Modernization Guide for N2 Controllers - Facility Explorer

Modernization Guide for N2 Controllers -Facility Explorer

LIT-12012045Building Technologies & Solutionswww.johnsoncontrols.com2019-03-22

ContentsContentsIntroduction...................................................................................................................................... 5

Choosing the right strategy............................................................................................................5

Scenario 1: legacy N2 Controller fails................................................................................................. 5

Scenario 2: small expansion.................................................................................................................5

Scenario 3: system modernization......................................................................................................6

Applying FX-PC Controllers as replacements for legacy N2 Controllers................................... 6

General differences and considerations....................................................................................... 7

Mounting................................................................................................................................................ 7

I/O interfaces......................................................................................................................................... 7

Zone bus not supported.......................................................................................................................7

XT bus not supported........................................................................................................................... 8

I/O wiring................................................................................................................................................8

N2 field bus network wiring.................................................................................................................9

Setting the N2 Controller address to be greater than 127.............................................................. 9

Programming tools and control logic...............................................................................................10

Downloading and commissioning.................................................................................................... 11

Integration into N2 Supervisor..........................................................................................................12

Specific device differences and considerations..........................................................................13

Replacing VMA14xx Series Variable Air Volume Modular Controllers..........................................13

Footprint considerations..........................................................................................................14

Point comparison......................................................................................................................14

I/O expansion comparison...................................................................................................... 15

Room Sensor comparisons......................................................................................................15

Control logic configuration......................................................................................................16

N2 Device and point configuration.........................................................................................16

N2 supervisor configuration....................................................................................................17

Replacing DX-9100 Extended Digital Controllers............................................................................ 18


Wiring connections comparison............................................................................................. 19


Additional considerations........................................................................................................ 23

Display comparison.................................................................................................................. 24


N2 device and point configuration.........................................................................................25

N2 Supervisor configuration................................................................................................... 25

Replacing UNT Unitary Controllers................................................................................................... 25




RLY Relay Module considerations...........................................................................................30

Zone bus considerations..........................................................................................................31





Replacing VAV1xx Variable Air Volume Box Controllers................................................................. 36

Footprint comparison...............................................................................................................36






Zone Terminal Unit considerations........................................................................................ 44

N2 Device and point configuration.........................................................................................44


Replacing AHU Air Handling Unit Controllers..................................................................................45

Footprint comparison...............................................................................................................45

Modernization Guide for N2 Controllers - Facility Explorerii



RLY Relay Module considerations...........................................................................................50

Function Module (FMK) considerations..................................................................................51


Zone Terminal Unit considerations........................................................................................ 52




Demolition and disposal............................................................................................................... 53

Converting to BACnet MS/TP field bus........................................................................................53

Device addressing..........................................................................................................................53

Control configuration for BACnet MS/TP.................................................................................... 54

Reusing existing N2 wiring for BACnet MS/TP........................................................................... 54

iiiModernization Guide for N2 Controllers - Facility Explorer

IntroductionAt Controller Configuration Tool (CCT) Release 10.1, a new enhancement was added enabling theFX-PC controller field bus to be configured for either BACnet® MS/TP or N2 networking protocol.This feature allows you to use certain FX-PC controllers as field replacements for legacy Metasys®or Facility Explorer® branded N2 controllers (hereafter referred to as legacy N2 controllers). Manyof these legacy N2 controllers are no longer in production, making direct replacement no longerfeasible.Customers with legacy N2 controllers installed in their building can benefit from N2-capable FX-PCcontrollers, because they enable cost-effective replacement and expansion of their installed base ofcontrollers by avoiding major control system renovation.These same customers also benefit from the more modern FX-PC controller technology, includingstate-based control, event-driven logic, and automatic tuning. In addition, the ability to switch theFX-PC controllers back to BACnet MS/TP provides customers with a cost-effective upgrade path to amodern, higher performance field bus technology.The modernization guide is intended to help you choose and implement the most appropriatestrategy for your customer. Also, this guide describes the key installation and configurationdifferences between the two families of controllers to help you prevent, minimize, and overcomeinstallation and configuration challenges.

Choosing the right strategyReplacement of legacy N2 controllers is driven by one of three scenarios. We recommend that youwork with your customer to develop a modernization plan (even if that plan is implemented in thefuture). With a modernization plan in place, you can better manage emergency replacement orsmall expansion scenarios.

Scenario 1: legacy N2 Controller failsIn this scenario, a legacy N2 controller fails, either electronically or mechanically. The customerneeds to replace just one controller. Consider the following options:Option 1: Replace the legacy N2 controller with an FX-PC controller configured for N2. See ApplyingFX-PC Controllers as replacements for legacy N2 Controllers for the key challenges to this option.Option 2: You may find Option 1 too challenging or not cost effective for just one controller. If so,consider finding a direct replacement. Many legacy N2 controllers are no longer in production.However, you may find direct replacements through sources other than new production. Forexample, you may find a direct replacement in the truck inventory of a service technician orthrough a Johnson Controls® distributor who has an inventory of legacy N2 controllers. Also, theJohnson Controls Repair Center has an inventory of refurbished legacy N2 controllers, as they offerrepair and return capability for these devices.Option 3: If the failed controller is used in a critical application and the situation is extremely time-sensitive, then you should consider moving a similar controller (if available) from a less criticalapplication and temporarily using it as a replacement. Then implement either Option 1 or 2 whentime permits.

Scenario 2: small expansionIn this scenario, your customer is planning to remodel their space, subdivide or rearrange existingspace, or expand their facility. As a result, their plan requires adding to their BAS either newequipment or existing equipment that was not previously connected to the BAS.Option 1: If only one or two new controllers are needed as additions to an existing N2 bus, youshould consider adding FX-PC controllers and configuring them for N2 protocol.Option 2: If many new controllers are needed, you should consider modernizing their BAS to useBACnet MS/TP. This option involves replacing the N2 supervisor with a BACnet supervisor, adding

5Modernization Guide for N2 Controllers - Facility Explorer

FX-PC controllers to operate the new or existing equipment, and configuring the FX-PC controllersfor BACnet protocol.

Note: If the existing N2 supervisor also supports managing BACnet MS/TP networks, then thesupervisor may not need to be replaced.

Scenario 3: system modernizationIn this scenario, the customer has an N2-based BAS and has previously replaced legacy N2controllers with N2-configured FX-PC controllers as a part of an earlier replacement scenario. Nowthe customer is contemplating future risk and the cost and disruption of more legacy N2 controllerreplacements.Option 1: You should consider modernizing the BAS to use BACnet MS/TP protocol. This optionrequires replacing the N2 supervisor with a BACnet supervisor, switching the existing N2-configured FX-PC controllers to BACnet, and replacing the remaining legacy N2 controllers withBACnet-configured FX-PC controllers.

Note: If the existing N2 supervisor also supports managing BACnet MS/TP networks, then thesupervisor may not need to be replaced. See Converting to BACnet MS/TP field bus for the keychallenges to this option.

Applying FX-PC Controllers as replacements forlegacy N2 ControllersTo apply FX-PC controllers as replacements for legacy N2 controllers, you need to consider thefollowing:Installation location

• Identify how and where the legacy N2 controller is physically mounted and wired.

• Determine if the existing controller enclosure is suitable for the replacement FX-PC controller byidentifying the amount of space available.

• If the replacement requires the addition of an FX-PCX to match point count, additional enclosurespace is required. Be sure that rework of a controller installation conforms to all local codes.For example, certain models of legacy controllers used spade lugs connectors; the replacementcontrollers use screw terminals.• Starting in 2005, the National Electrical Code (NEC) Article 409 mandates specific detail

marking in control enclosures. This requirement applies to any enclosures replaced orexpanded to hold the FX-PC products and accessories.

Input/Output (I/O) profileIdentify the number and types of all input and output devices connected to the legacy N2controller, including the signal types required to interface them.Sequence of operationObtain the expected sequence of operation from the legacy N2 controllers. Use one of thefollowing methods:

• Use the legacy N2 controller’s programming tool (HVACPro or GX Tool) to upload the legacy N2controller’s application file.

• If you are unable to upload the exact file from the target controller (for example, if the controllerdoes not power up), then obtain a saved backup file from the project archives.

Modernization Guide for N2 Controllers - Facility Explorer6

• If you are unable to obtain the exact file, then consider uploading a nearby controller with thesame or similar application.

• If you are unable to upload or obtain an exact or similar application file, then analyze themechanical equipment characteristics and control sequence from visual inspection or jobdocumentation and then confirm the expected sequence of operation with the customer.

N2 supervisor integrationIdentify which type of N2 supervisor (for example, NCM, N30, Companion, Facilitator, NAE, or FXSupervisory Controller) is providing supervisory control over the legacy N2 controller. Identify allcontrol features and services (for example, scheduling, optimal start/stop, alarming, trending,interlocking, global data sharing, supervisory code [LCT, GPL, JC Basic], or graphics) the N2supervisor is applying to the legacy N2 controller.

General differences and considerationsThis section details the general differences that exist between the legacy N2 controllers and FX-PC controllers. For unique differences based on the specific model of legacy N2 controller beingreplaced, see Specific device differences and considerations.

MountingFX-PC controllers are not physically identical to legacy N2 controllers and have a different mountingfootprint. As a result, when using FX-PC controllers to replace legacy N2 controllers, ensure that theintended mounting location (for example, if reusing the existing control panel) has enough spaceto accommodate the FX-PC controller. See Specific device differences and considerations for specificdimensions for legacy N2 controllers and their suggested FX-PC controller replacements.

Note: Depending on the I/O count used on the legacy N2 controller, two or more physicalcontrollers (an FX-PCG/FX-PCX combination) may be needed to replace a single N2 controller.

I/O interfacesFX-PC controllers have different numbers and types of onboard I/O than legacy N2 controllers.Which replacement FX-PC you select depends on how the legacy N2 controller was applied in thefield and how many I/Os were actually used by the legacy N2 controller. For more information, seeSpecific device differences and considerations to understand the onboard I/O differences betweenlegacy N2 controllers and FX-PC controllers.FX-PC controllers feature flexible input interfaces, allowing these controllers to support most of thesame sensors supported. However, some room sensors (for example, TE-6100-11/12, TE-67xx, orTE-67xx) that are used with legacy N2 controllers feature modular (phone) jack connections. Thesesensors require adaptation for use with the FX-PC controllers. See Specific device differences andconsiderations.

Zone bus not supportedLegacy UNT, VAV, AHU, and VMA1400 controllers supported a Zone Bus for connecting to:

• TMZ Series network room sensors

• TE-77 Series wireless temperature sensor and receivers

• ZTU Zone Terminal Units

• M100C Series networked actuatorsFX-PC controllers do not support the Zone Bus and do not support these devices. Instead, FX-PCcontrollers feature a different technology bus called the Sensor Actuator (SA) bus to connect NSSeries Network Sensors, FX-DIS1710 Local Display/Keypads, and FX-PCX Expansion I/O Modules.


When using an FX-PC controller to replace a legacy N2 controller that uses a TMZ sensor, you mustalso replace the TMZ sensor with an NS Series Network Sensor. Make note of any wiring changeor modifications needed when using a new sensor. The NS sensor provides many of the samefunctions as the TMZ sensor, including zone temperature sensing, zone temperature setpointadjustment, and LCD display. However, the NS sensor is housed in an enclosure that has a differentuser interface. For example, the NS sensor features a dial to adjust the zone temperature setpoint,whereas the TMZ features a pushbutton keypad. As a result, we recommend you work with yourcustomer to help them and their building’s occupants understand how to use the adjustmentfeatures of the new NS sensor.When using an FX-PC controller to replace a legacy N2 controller which uses a TE-77xx wirelesstransmitter/receiver, you must also replace the TE-77xx with the Facility Explorer One-to-OneWireless Room Sensing System. For more information, refer to the Facility Explorer One-to-OneWireless Room Sensing System Product Bulletin (LIT-12011664).When using an FX-PC controller to replace a legacy N2 controller that uses a ZTU Zone TerminalUnit, you must replace it with an FX-DIS1710 Local Display/Keypad.When using an FX-PC controller to replace a legacy N2 controller that uses an M100C zone busactuator, you must replace the actuator with a non-networked actuator. For dampers, use theM9100/M9200 Series. For valves, use the VA7800/VA-7150 Series. To control the new actuator, usean available analog output or configurable output on the FX-PC controller. If none are available, addan FX-PCX Expansion I/O Module.

XT bus not supportedLegacy DX-9100 Extended Digital Controllers supported an optional XT Extension Module withassociated XP Expansion I/O Modules to expand the DX-9100's input and output interfaces. FX-PCcontrollers do not support the XT/XP modules. Instead, for I/O expansion, the FX-PC controllerssupport the SA bus for connecting FX-PCs to IOM Expansion I/O modules.When using an FX-PC controller to replace a DX-9100 controller, you must also replace the XT/XPmodules. Either use available I/O interfaces on the FX-PC main controller or add FX-PCX ExpansionI/O modules.

I/O wiringSeveral differences exist between the I/O wiring connections of the FX-PC controllers and the legacyN2 controllers. Most FX-PC controllers have terminals that use screw type I/O wiring connections,except for FX-PCV models, which have spade terminals. Most legacy N2 controllers use spadelug type I/O wiring connections. You may need to modify the ends of the existing I/O wiringaccordingly.Also, FX-PC controller wiring terminal locations may not line up with the existing wiring. To alignwires to the corresponding FX-PC controller, you many need to:

• reroute wire from the enclosure terminal block to the FX-PC controller

• add longer wires to many of the controller terminals

• splice additional length onto existing wire if your installation does not have a terminal block

When modifying the I/O wiring to accommodate the replacement FX-PC controller, follow theserecommendations, whenever possible:

• use the same color insulation to preserve wiring standards

• use wire of the same material and gauge

• never splice copper to aluminum conductors without using an appropriate aluminum to copperconductor

• use positive mechanical connections in all splices


• follow splice manufacturer's instructions and crimp tool recommendations carefully

• consider using soldered connections if the enclosure location allows

• completely insulate each individual splice to protect from electrical shorts and corrosion

• use shrink-sleeve tubing, which provides a more reliable insulation than adhesive tape in mostapplications

N2 field bus network wiringWhen configured for N2, FX-PC controllers conform to N2 field bus networking standards. Whenusing an N2-configured FX-PC controller to replace a legacy N2 controller on an N2 field bus, youcan expect the same network performance. However, if the installation’s existing N2 network isalready heavily loaded or is frequently reporting off-line devices, then you should take steps toimprove the network performance before replacing legacy N2 controllers with FX-PC controllers.Refer to the N2 Communication Technical Bulletin (LIT-636018) and follow all N2 field bus networkingrules, including those for the following instances:

• Segment and total line length

• End-of-line terminations

• Number of devices per segment, between repeaters

Setting the N2 Controller address to be greater than 127N2-configured FX-PC controllers support the full range of possible N2 device addresses supportedby the N2 protocol standard (1-255); however, they require special configuration for addressesabove 127.

Note: This special configuration is required because FX-PC controller addresses above 127were originally intended for use with the Wireless Field Bus system.

To set the FX-PC controller's N2 address to be greater than 127, follow these steps:

1. Disconnect the 24 VAC supply from the FX-PC controller.

2. Remove the FC Bus connector from the FX-PC controller.

3. Set the FX-PC controller's address DIP switch to the desired N2 address.

4. Set the address switch segment labeled 128 to OFF.

Figure 1: Switch setting for address 149 with 128 segment OFF

5. Reconnect the 24 VAC supply to the controller.


6. Using a CCT tool connection at the FX-PC controller’s SA bus, download the firmware and N2-configured controller application file. The download process prompts you to confirm switchingthe communication protocol to N2.

7. Click OK to accept.

8. After the download has completed, disconnect the 24 VAC supply to the FX-PC controller.

9. Set the address switch segment labeled 128 to ON.

10. Reattach the FC Bus connector to the FX-PC controller.

11. Reconnect the 24 VAC supply to the FX-PC controller.

Programming tools and control logicCCT is the programming and commissioning tool for the FX-PC controller family, and its controllogic capabilities are similar but not identical to those of the legacy N2 controller programmingtools (for example, HVACPro and GX Tool). No utilities are available to convert the legacy N2controller's logic to be usable by CCT, and as a result, you need to recreate the control logic for thereplacement FX-PC controller using CCT.Recreating a UNT, VAV, VMA, or AHU controller application that was programmed with HVACProshould be straightforward. The CCT System Selection Wizard and Sideloop Wizard provide controllogic creation capabilities that are nearly identical to HVACPro's Question and Answer (Q&A) wizardand Sideloop wizard.Figure 2 shows how to begin configuring a new system in the tool. Figure 3 shows the N2Compatibility Options in the System Selection Tree.

Figure 2: New System


Figure 3: N2 Compatibility Options

Recreating a DX-9100 control application that was programmed with the GX Tool is morechallenging. The GX Tool was a custom programming tool which allowed the programmer tocreate custom control logic by connecting together various predefined logic modules to its I/O.CCT provides a similar custom programming interface using predefined logic modules, but itslogic modules are significantly different from the GX Tool's. Also the CCT programming canvas issignificantly different from the GX-Tool's. At CCT Release 10.1 a new Global Sequencer logic modulewas added that provides similar functionality as the GX Tool's Sequencer and Binary Sequencermodules.The control application programmed by CCT is significantly more advanced, containing moderncontrol advancements such as state-based control, event-driven logic, and automatic tuning.

Note: The N2 Compatibility Options option button does not appear for Central Heating,Central Cooling Plants, and Simple Central Plants because these systems typically use customlogic. For more information on programming and downloading controllers using CCT 10.1,refer to the Controller Tool Help (LIT-12011147).

Downloading and commissioningLegacy N2 controllers support local application downloading and commissioning using theappropriate programming and commissioning tool hosted on a computer (for example, HVACProor GX Tool), the computer's serial interface, and an RS-232 to RS-485 adapter (for example, the MM-CVT or IU-9100 or Zone Bus adapter).


FX-PC controllers also support local downloading and commissioning; however, they require adifferent technology. For local downloading and commissioning, FX-PC controllers require that CCTis hosted on a computer with a Bluetooth® interface or a third-party Bluetooth interface, and thatan FX-BTCVT Bluetooth Commissioning Converter is connected to the FX-PC controller's SA Bus.NCM and NAE Series supervisory devices contain a feature called Passthrough, which enablesyou to remotely download and commission legacy N2 controllers. FX Supervisory ControllerPassthrough do not support N2-configured FX-PC controllers. When you use an FX-PC controllerto replace a legacy N2 controller that is supervised by an FX Supervisory Controller, you losethe capability to use Passthrough to remotely download and commission the N2-configuredcontroller. You and your customers need to be aware that programming and commissioning theN2-configured FX-PC controller must be performed onsite with access to the FX-PC controller's SAbus connection.

Integration into N2 SupervisorWhen using FX-PC controllers to replace legacy N2 controllers, the N2 supervisor's configurationmay be impacted. The legacy N2 controller families have existed through several generations ofN2 supervisors. Depending on the timing of the original installation, legacy N2 controllers maybe supervised by one of many types and brands of N2 supervisors, including the NCM, NAE, N30,Companion, Facilitator, and FX Supervisory Controllers. N2-configured FX-PC controllers shouldwork with all Johnson Controls N2 supervisors. However, you must consider certain configurationsteps to ensure the system operates as expected after the replacement.In many instances, you can reconfigure the N2 supervisor online. However, some changes mayrequire off-line configuration and a supervisory controller download. Therefore, you may need tohave the appropriate tool such as System Configuration Tool (SCT) for NAEs, Project Builder forN30s, and FX Workbench for FX Supervisory Controllers.A legacy N2 controller is mapped into an N2 supervisor by defining in its database the controller'sN2 device type, N2 point types, and N2 point addresses. At CCT Release 10.1, an N2 Mappingfeature was added, allowing you to configure this information to resemble that of the legacy N2controller being replaced.

• N2 Device Type: With the CCT N2 Mapping feature, you can define the FX-PC controller's N2device type to be a UNT, AHU, VAV, or VND to match the legacy N2 controller being replaced. Forexample, consider a situation where you are replacing a UNT controller, and it is mapped into theN2 supervisor as a UNT N2 device type. With the N2 Mapping feature, you can configure the FX-PC controller to have a UNT N2 device type to match the N2 supervisor's definition.

Note: DX and FX-PCV controllers cannot be directly mapped as before and must now bedefined as VND devices.

• N2 Point Information: With the CCT N2 Mapping feature, you can define the FX-PC controller'sapplication points so that the N2 Short Name, Point Type, and Point Address match those of thelegacy N2 controller being replaced. For example, consider a situation where you are replacinga legacy UNT1x1 controller, and its Zone Temperature application point is mapped into the N2supervisor with a short name of ZN-T, and point type and address of AI-1. With the N2 Mappingfeature, you can configure the FX-PC controller's Zone Temperature application point to have thesame ZN-T, AI-1 information to match the N2 supervisor's definition.

Note: This functionality helps minimize the reconfiguration (device and point mapping)needed at the N2 supervisor, but may not be appropriate for all replacement situations. SeeSpecific device differences and considerations for more information.

Even with the N2 Mapping feature, the N2 supervisor's database may still require some changes.The FX-PC controller's application may not include all of the same application points as the legacyN2 controller being replaced. For example, some legacy N2 controller application points have noequivalent in FX-PC controllers. Therefore, the N2 supervisor reports these points as offline unlessthey are unmapped (deleted) from the N2 supervisor's database.


Also, some legacy N2 controller application points may be defined differently in FX-PC controllers,which would require remapping the FX-PC controller's N2 points in the N2 supervisor. Thisremapping may in turn require other configuration changes to the N2 supervisor, includingchanges to trend and alarm extensions, bound connections to graphics, and source and destinationconnections to system-wide control logic.Although the N2-configured FX-PC controller is functionally similar to the legacy N2 controller itreplaces, any changes to point mapping and associated changes to supervisory functionality maycause some confusion for your customers and operators. For example:

• The operator interface for adjusting the standby and unoccupied zone setpoints for VMA14xxcontrollers uses offset values, which are added to or subtracted from the zone setpoint; whereasthe interface for adjusting the standby and unoccupied zone setpoints for FX-PC controllers istheir actual, discrete values.

• N2 Open Override command to an FX-PC controller object value does not persist after powercycle.

• Commands to a Default Value attribute do not persist after a power cycle.

• Writing to a point in the FX-PC controller through the N2 network integration changes thepresent value of the attribute but does not write the value to non-volatile memory. Thismeans that the new value is not persisted following a power cycle of the FX-PC controller. Theworkaround is to use the Setpoint command to update the value in non-volatile memory.

Be sure to introduce the changes to your customer and the system operators accordingly.

Specific device differences and considerationsThe following table shows the legacy N2 controllers that can be functionally replaced with FX-PCcontrollers, along with a suggested FX-PC controller replacement.Table 1: Suggested replacement for legacy N2 Controllers

Legacy N2 Controller model Suggested FX-PC Controller replacementVMA14xx FX-PCV1832DX-9100 FX-PCA3611 plus PCX (to meet I/O)UNT1xx FX-PCG16xxUNT11xx FX-PCG26xxVAV1xx plus EDA/ATP FX-PCV1832 for VAV box applications

FX-PCG16xx for Expansion I/O applicationsAHU FX-PCA3611 plus FX-PCX (to meet I/O)

Replacing VMA14xx Series Variable Air Volume ModularControllersThe VMA14xx Series Variable Air Volume Modular controller was used extensively for VAV boxcontrol. The VMA14xx featured the integration of a differential pressure sensor and rotatingactuator into the controller package to reduce its overall mounting footprint and simplifyinstallation. The recommended FX-PC Series replacement controller model for the VMA14xx is theFX-PCV1832. See the following sections for key differences.


Footprint considerations• The FX-PCV1832 has a slightly larger footprint than the VMA14xx.

• Replacement in the same enclosure space is possible. However, it may be tight for someinstallations.

• The location of the retaining screw for the FX-PCV1832 controller is further away from theactuator shaft than on the VMA14xx.

Figure 4: Footprint considerations

Table 2: VMA14xx and FX-PC replacement dimensions

Dimension VMA14xx FX-PCV1832Height 153 mm (6 in.) 165 mm (6.5 in)Width 102 mm (4 in.) 125 mm (4.92 in.)Depth 102 mm (4 in.) 73 mm (2.9 in.)

Point comparisonTable 3: VMA14xx to FX-PC Controller point comparison

VMA1410 VMA1420 FX-PCV1832 FX-PCX2711

Termination Type Space lugs Spade lugs Spade lugs Screw terminalsAnalog Inputs 2 4 0 0Binary Inputs 3 0 0 0Universal Inputs 0 0 3 2Analog Outputs 0 2 0

Binary Outputs 0 5 3 0Configurable Outputs 0 0 2 0Universal Outputs 0 0 0 2Relay Outputs 0 0 0 2


Table 4: VMA14xx to FX-PC Controller point comparison

VMA14xx pointtype

Characteristic FX-PC Controllerpoint type

Characteristic

AI RTD Temp. Elem. (1k Ni, Si,Pt, or 2k NTC)

0-10 VDC Transducer

1.6k ohm SetpointPotentiometers

UI Resistance temperaturedetector (RTD) (1k Ni, 1k Pt,A99B Si)

Negative temperaturecoefficient (NTC) (10k Type L,2.252k Type 2)

Voltage Mode, 0–10 VDC

Current Mode, 4–20 mA

Resistive Mode, 0–2k ohmUI Dry Contact Maintained ModeBI Dry contactBI Dry Contact Maintained ModeAO Voltage Mode, 0–10 VDCCO Voltage Mode, 0–10 VDC

AO 0-10 VDC at 10 mA

UO Voltage Mode, 0–10 VDCBOBO 24 VAC Triac at 0.5ACO

24 VAC triac

I/O expansion comparisonBeginning with CCT Release 10.1, the FX-PCV1832 controller can use FX-PCX Expansion I/O Modulesfor I/O expansion on the Sensor Actuator (SA) Bus.

Room Sensor comparisonsTable 5: Room Sensor comparisons

Attribute VMA14xx FX-PCV1832 ImplicationNetworkSensorsSupported

TMZ Series ZoneSensors

NS Series NetworkSensors

Replace TMZ with NS sensor.

TE-77 Wireless RoomSensor Transmitter/Receiver

FX-WRZ7860 One-to-One Wireless SensingSystem

Replace TE-77 with FX-WRZ7860One-to-One Wireless SensingSystem.

Wireless SensorsSupported

WRS-TTxx FX-WRZ7860 One-to-One Wireless SensingSystem

Replace WRS-TTxx with FX-WRZ7860 One-to-One WirelessSensing System.

Analog SensorsSupported

TE-67 and TE-68Series

TE-77 and TE-68Series

Reusing sensors is possible.

Note: Some room sensors (TE-6100-11 and -12, TE-67xx, and TE-67xx) featured modular(phone) jack connections and require adaptation for use with the FX-PCG controllers.


If you reuse a TE-67xx or TE-68xx Series sensor, be aware that the single setpoint or no setpointmodels feature an LED, but the FX-PCG controller does not support the LED. As a result, you need tochange the sensor's DIP switch settings as follows:

• If Temporary Occupied function is required for the application, set the DIP switch positionson the back of the sensor to down, up, and down (LED disabled, but Sensor and Push Buttonenabled).

• If Temporary Occupied function is not required, set the DIP switch positions to down, down, anddown (LED and PB disabled).

Figure 5: TE-67xx and TE-68xx Sensor DIP Switch Setting

Dual setpoint sensor models do not feature an LED, and as a result, you should not need to changethe DIP switch settings.

Control logic configurationTable 6: Control logic comparison

Attribute UNT FX-PCG ImplicationProgramming Tool HVACPro CCT Recreate the UNT’s

control logic with CCT.Q/A Session for fan coils,unit vents, packagedrooftops, and heatpumps

System Selection Wizardfor fan coils, unit vents,packaged rooftops, andheat pumps

Control Logic

Sideloop Session Sideloop Wizard

Recreating the UNT'scontrol logic shouldbe straightforward byusing the CCT SystemSelection Wizard orSideloop Wizard.

N2 Device and point configurationLegacy VMA14xx controllers identified themselves to their N2 supervisor as a VMA device type.The FX-PCV1832 does not support identifying itself to its N2 supervisor as a VMA device type. As aresult, you must use the CCT's N2 Mapping interface to set the FX-PCV1832 controller's device typeto VND and reconfigure the N2 supervisor so that the FX-PCV controller is mapped as a VND device.


Figure 6: Using CCT to set the FX-PCV1832 device type to VND

Additionally, the CCT System Selection Wizard for the Single Duct VAV Box (VAV-SD) applicationautomatically defines the FX-PCV1832 controller's N2 point mapping table to resemble theVMA14xx controller's N2 point map. Doing so eliminates the need to change the N2 supervisor'spoint mapping configuration. All other VAV box control applications (for example, dual ductapplications) require you to use the CCT N2 Mapping interface to manually create the N2 pointmapping table.

N2 supervisor configurationAs described previously, the FX-PCV1832 does not support identifying itself to an N2 supervisor asa VMA device type. As a result, you must reconfigure the N2 supervisor so that it is mapped as aVND device. Also, if the FX-PCV1832 N2 point mapping does not exactly match its N2 supervisor'spoint mapping, then you need to reconfigure the N2 supervisor so that it does. The procedure forperforming these changes depends on the type of N2 supervisor.

• For an N30 type N2 supervisor, perform these changes offline using the Project Builder tool.Refer to the Project Builder User's Guide (LIT-693205).

• For an NAE type N2 supervisor, perform these changes offline using the System ConfigurationTool (SCT). Refer to N2 Integration with the NAE Technical Bulletin (LIT-1201683).

• For an NCM type N2 supervisor, changing the NCM database requires you to delete the oldhardware and define the new hardware. The incremental DDL compile method (@NC+) using theDELETE keyword simplifies the NCM database change. GPL and JC Basic processes may not needto be recompiled. Refer to the DDL Programmer's Manual (LIT-630010).

• For an FX Supervisory Controller type N2 supervisor, perform these changes offline using FXWorkbench. Refer to the FX Workbench User's Guide (LIT-12011149).

For replacements that switch to VND Device Type, point mapping is unrestricted. To make the FX-PCV1832 replacement operation as similar as possible to the old VMA14xx device:

• Select a Supervisor Object Type that matches the replaced controller point.

• For multi-state objects, select an appropriate States Text table.

• Use the Supervisor Object Definition to restrict commands.


Table 7: Point limitations of PCV1832

Network point type Network point addressAI 1-8BI 1-8AO 1-8BO 1-8ADF 1-256ADI 1-256BD 1-256

Replacing DX-9100 Extended Digital ControllersThe DX-9100 Extended Digital Controller, like its predecessor, the Lab and Central Plant (LCP)controller, was used most popularly for central plant and air handling unit control; however,its flexible programmability enabled it to be applied to a wide variety of equipment controlapplications, especially those requiring custom configurations. Also, its onboard real-time clock andoperator interface made it popular for stand-alone equipment control applications.The recommended FX-PC replacement controller model for the DX-9100 is the FX-PCA3611. See thefollowing sections for key differences.

Note: This section includes details for the N2 versions of the DX-9100 only. Althoughreplacement of the LonWorks® N2E devices face many of the same challenges, you mustreplace devices such as the DX-9121 (TP78 topology) and DX-9200 (FTT topology) with LNSeries programmable LonWorks controllers.

Footprint considerationsThe external terminals on the base of DX-9100 makes it about 2 inches taller but about one inchnarrower than the FX-PCA3611. Replacement in the same enclosure space may be possible whennot using all of the I/Os on the DX. Special consideration is required for DX-9100 Series controllersthat mount on the face of an enclosure. You may need to find a retrofit solution such as using anew panel enclosure.

Figure 7: Footprint considerations - FX-PCA3611


Table 8: DX-9100 and FX-PCA3611 replacement dimensions

Dimension DX-9100x FX-PCA3611Height 200 mm (7.9 in.) 150 mm (5.9 in.)Width 184 mm (7.2 in.) 220 mm (8.7 in.)Depth 100 mm (3.9 in.) 57.5 mm (2.3 in.)

Consider that the onboard I/O count for an FX-PCA3611 is slightly less than a DX-9100. As a result,you may need to add an FX-PCX Expansion I/O Module even if the old installation did not use XT/XPextension modules.Installations that used one or more extension module sets may need extensive rearrangingto accommodate the equivalent point count FX-PCXs. Some space is regained as the XTcommunication module is removed.

Figure 8: Footprint considerations - FX-PCX3711

Table 9: XT/XP and FX-PCX replacement dimensions

Dimension XT Plus 1 XPs XT Plus 4 XPs FX-PCX3711Height 118 mm (4.65 in.) 118 mm (4.65 in.) 150 mm (5.9 in.)

Width1 140 mm (5.5 in.) 350 mm (13.8 in.) 90 mm (3.5 in.)

Depth 57 mm (2.25 in.) 57 mm (22.5 in.) 53 mm (2.1 in.)

1 Each XT or XP module is 70 mm (2.76 in.) wide.

Wiring connections comparisonTable 10: Wiring connection similarities, differences, and implications

Attribute DX-9100 FX-PCA3611 ImplicationI/O Wiring


Table 10: Wiring connection similarities, differences, and implications

Attribute DX-9100 FX-PCA3611 ImplicationConnectionLocation

See Figure 9. See Figure 9. You can reuse the existing I/Owiring if the existing wiring is longenough to reach the FX-PCA3611I/O wiring connection points. Ifnot, you need to lengthen the I/Owiring.

Connection Type Fixed screwterminalconnectors

Fixed screwterminalconnectors

No change is necessary.

N2 WiringConnectionLocation

See Figure 9. See Figure 9. You can reuse the existing I/Owiring if the existing wiring is longenough to reach the FX-PCA3611wiring connection points. If not,you need to lengthen the I/Owiring.

Connection Type 4-wire removablescrew terminalconnector

4-wire removablescrew terminalconnector

Replace the DX-9100's N2 wiringconnector with the FX-PCA3611'swiring connecter.

Power Supply WiringConnectionLocation

See Figure 9. See Figure 9. You can reuse the existing powersupply wiring if the existing wiringis long enough to reach the FX-PCA3611 power supply connectionpoint. If not, you need to lengthenthe I/O wiring.

Connection Type Fixed, 2-wire screwterminal connector

Removable, 2-wirescrew terminalconnector

No change is necessary.


Figure 9: Comparison between DX-9100 and FX-PCA3611 Controllers' wiring connection locations

Point comparisonTable 11: DX point comparison

Code number Terminationtype

AI BI AO BO RO

DX-9100-8154 ScrewTerminal

8 8 2 6 —

DX-9100-8454 ScrewTerminal

8 8 8 6 —

Expansion Modules used with XT-9100-8304 communications interface:XP-9102 6 2 —XP-9103

—8

XP-9104 4 4XP-9105 8

—

XP-9107

—

—

—

—4

Expansion modules used with XTM-905-5 communications interface:XPA-821 6 — 2 — —XPB-821

ScrewTerminal — 8 — — —

XPL-401XPE-401

3

XPE-404

—

4XPT-401

4

4XPT-861

ScrewTerminal

—

—

—

8—


Table 12: FX-PCA/FX-PCX point comparison

Codenumber

Terminationtype

UniversalInputs (UI)

BI AO BO ConfigurableOutputs (CO)

UniversalOutputs(UO)

RO

FX-PCA2611

6 2 2 3 4 —

FX-PCA2612

5 4 — — 5

FX-PCA3611

ScrewTerminal

8 6 6 6

—

—

—

FX-PCX1711

— 4 — —

FX-PCX2711F

2

—

2 2

FX-PCX2721

8 2 — —

FX-PCX3711

4

—

4 4

FX-PCX3721

16

—

FX-PCX3731

—

8

—

8

—

FX-PCX4711

6 2 2 3 4

FX-PCX1711

— 4

— —

FX-PCX2711

ScrewTerminal

2 —

— — —

2 2

Table 13: DX/XP point comparison

DX/XP pointtype

Characteristics FX-PCA/FX-PCXPoint Type

Characteristics

AI RTD (Ni1000, Pt1000, A99)

0-10 VDC (300k minimumimpedance)

0/4-20 mA (100 ohmimpedance)

UI Resistance temperaturedetector (RTD) (1k NI, 1k PT,A99B SI)




Resistive Mode, 0–2k ohmDI Potential-free contacts UI Dry Contact Maintained Mode


Table 13: DX/XP point comparison

DX/XP pointtype

Characteristics FX-PCA/FX-PCXPoint Type

Characteristics

Transition counter function:maximum 10 Hz

BI Dry Contact Maintained Mode

Pulse Counter/AccumulatorMode (High Speed), 100 Hz

AO Voltage Mode, 0–10 VDC

Current Mode, 4–20 mACO Voltage Mode, 0–10 VDC

AO Version 1: [AO1-2]

0-10 VDC (maximum 10 mA)

0/4-20 mA (maximum 500ohm)

Version 2

0-10 VDC (AO1-2 and AO9-15)

0/4-20 mA (AO1-2 and AO9-10only)

UO Analog Output, Voltage Mode,0–10 VDC

Analog Output, Current Mode,4–20 mA

BOCO

24 VAC TriacDO Triac 24 VAC, 0.5 amperecontinuous (0.8 ampere peak)

UO Binary Output Mode, 24 VAC/DC FET

RO XP9107: Latching relays

XPL-401: Latching relays,manual override

RO Signal mode: Maintained

Startup OFF State Enable:False

Single-Pole, Single-Throw: UL916:1/4 hp 120 VAC,

1/2 hp 240 VAC; 360 VA

Pilot Duty at 120/240 VAC(B300); 3 A Non-inductive24-240 VAC; EN 60730: 6 (4) AN.O. or N.C. only

RO XPE-401: Electricallymaintained, manual override

RO Signal mode: Maintained

Startup OFF State Enable: TrueRO XPE-404: On/Off or pulse,

manual override (commonsupply)

RO Signal mode: Start Stop

Startup OFF State Enable: True

Additional considerationsWhen using active sensors, be sure that the FX-PC controller and I/O module can provide sufficientcurrent at the voltage required by transmitters.Current mode of Universal Input range is limited to 4-20 mA. The FX-PC controller does not supportthe 0-20 mA Analog Input range.FX-PC controller power requirements are greater than DX-9100. Recalculate power requirements forall replacement configurations. Include any auxiliary devices that are also powered by the DX-9100


or its transformer. Remember to include power requirement for any FX-DIS1710 module whencalculating transformer capacity.The DX family used a slightly different communication protocol. The FX-PC family controllers usethe N2 Open protocol.The real-time clock and alarm functions available in FX-PC controllers support many stand-aloneapplications.

Display comparisonThe DX-9100 featured an onboard LCD display and an optional DT9100 display unit. You canpartially duplicate the local display functionality by replacing it with an FX-DIS1710. However, theFX-DIS1710 does not provide access to real-time clock functions (such as scheduling, trending, andalarming).Table 14: Differences between DX-9100 front panel display, DT-9100 local display, and FX-DIS1710

Function or feature DX front panel DT-9100 local display FX-DIS1710Show attachedexpansion modulepoints

Yes Programmable Yes

Password protection No Programmable Single userI/O Override capability LCP Key inserted Programmable YesSetpoint adjustment LCP Key inserted Programmable YesDisplay Real TimeClock, Calendar,Exception Days,Daylight Saving Time

Yes Display date and timeonly

Display date and timeonly

Adjust Clock andSchedule functions

LCP Key inserted No No

Control logic configurationTable 15: Control logic comparison

Attribute DX-9100 FX-PCA3611 ImplicationProgramming Tool GX-Tool CCT You can recreate the

DX-9100's controllogic with CCT, butit requires customprogramming using adifferent programmingtool interface.

Programming Modules Sequencer

Binary Sequencer

Global Sequencer

DX-9100 applications created with the GX Tool cannot be duplicated using the CCT System SelectionWizard. As a result, you must recreate the control application using the CCT custom programmingcapabilities.


N2 device and point configurationDX-9100 controllers identify themselves to their N2 supervisor as a Sys91 device type. The FX-PCA3611 does not support identifying itself to its N2 supervisor as a Sys91 device type. As a result,you must use the CCT N2 Mapping interface to set the FX-PCA3611 controller’s device type toVND, and reconfigure the N2 supervisor so that it is mapped as a VND device. See N2 Supervisorconfiguration for more information.In addition, you must use the CCT N2 Mapping interface to manually create the N2 point mappingtable.

N2 Supervisor configurationAs described previously, the FX-PC controllers do not support identifying themselves to an N2supervisor as a SyS91 device type. As a result, you must reconfigure the N2 supervisor so that theFX-PC controller is mapped as a VND device. Also, if the FX-PCA3611 N2 point mapping does notexactly match its N2 supervisor point mapping, then you need to reconfigure the N2 supervisorso that it does match the supervisor point mapping. The procedure for performing these changesdepends on the type of N2 supervisor.





For replacements that switch to VND Device Type, point mapping is unrestricted. To make the FX-PCA3611 replacement operation as similar as possible to the old DX-9100 controllers:




Replacing UNT Unitary ControllersUNT Unitary Controllers were used extensively for controlling packaged rooftop and heat pumpunits, small air handling units, unit ventilators, fan coils, and other terminal units serving a singlezone or room. They were also frequently used as I/O devices for generic monitoring and control.Various UNT models were offered, and they were applied to a wide range of applications. To replacea UNT controller in an application where only a few of its inputs are being used, we recommendusing the FX-PCG1611controller. To replace a UNT controller in an application where most or all ofits inputs are being used, we recommend using the FX-PCG2611controller. If the FX-PCG controllerdoes not have enough onboard I/O to meet the replacement application requirements, then addFX-PCX Expansion I/O Modules. Make note of any special application controllers such as for usein low or extended temperature applications. Contact your Johnson Controls representative ortechnical support group for recommendations.

Footprint considerationsAll models of UNT controllers have a footprint slightly larger than an FX-PCG1611 controller, soreplacing a UNT with an FX-PCG1611 using the same enclosure space is highly probable. The FX-


PCG2611 is approximately 1 in. (2.5 cm) wider than a UNT. As a result, if you use an FX-PCG2611 toreplace a UNT, be sure to verify that enough space is available in the enclosure.

Figure 10: Dimensional comparison of UNT versus FX-PCG1611


Figure 11: Dimension comparison of UNT versus FX-PCG2611

Table 16: Dimensional comparison of UNT versus FX-PCG1611 and FX-PCG2611

Dimension UNT (All Models) FX-PCG1611 FX-PCG2611Height 165 mm (6.5 in.) 150 mm (5 9 in.) 150 mm (5 9 in.)Width 163 mm (6.4 in.) 164 mm (6.5 in.) 190 mm (7.5 in.)Depth 56 mm (2.2 in.) 54 mm (2.1 in.) 54 mm (2.1 in.)

Wiring connections comparisonTable 17: Wiring connection similarities, differences and implications

Attribute UNT FX-PCG ImplicationI/O WiringConnectionLocation

See Figure 12. See Figure 12. You can reuse the existing I/Owiring if the existing wiring is longenough to reach the FX-PCG I/Owiring connection points. If not,you need to lengthen the wiring.

Connection Type Spade lugconnectors

Fixed screwterminalconnectors

Remove spade lug connectorsfrom I/O wiring.


Table 17: Wiring connection similarities, differences and implications

Attribute UNT FX-PCG ImplicationN2 WiringConnectionLocation

See Figure 12. See Figure 12. You can reuse the existing I/Owiring if the existing wiring is longenough to reach the FX-PCG N2connection point. If not, you needto lengthen the wiring.

Connection Type Removable, 3-wirescrew terminalconnector


Replace the UNT's N2 wiringconnector with the FX-PCGs.


See Figure 12. See Figure 12. You can reuse the existing powersupply wiring if the existing wiringis long enough to reach the FX-PCGpower supply connection point.If not, you need to lengthen thewiring.

Connection Type Spade lug withremovable 2-wirescrew terminalconnector


Remove existing connectors frompower.

Figure 12: Wiring layout comparison of UNT versus FX-PCG

Point comparisonTable 18: UNT Point comparison


AI BI AO BO RO

UNT110/120UNT112/113

Spade Lug 6 4 — 8 —


Table 18: UNT Point comparison


AI BI AO BO RO

UNT111/121 2 6UNT140 — 8UNT141

ScrewTerminal

6 42 6

UNT1108 — — 8UNT1126 2 — 6UNT1144

SpadeLug withRemovableScrewTerminalOption

6 4

4 — 4

Table 19: FX-PCG point comparison

Codenumber

Terminationtype

UniversalInputs (UI)



RO

FX-PCG1611 2 1 — — —FX-PCG2611

ScrewTerminal 6 2 2

3—

42

FX-PCG2711

2 — 2

FX-PCG2721 8 2 —

—

FX-PCX3711

ScrewTerminal

4

—

—

—

4

—

4

Note: Add FX-PCXs as required to match point count need.

Table 20: UNT to FX-PCG/FX-PCX Controller point comparison

UNT point type Characteristic FX-PCG/FX-PCXpoint type

Characteristic

AI RTD Temp. Elem. (NI, SI orPT)

0-10 VDC Transducer

2k ohm SetpointPotentiometers

UI Resistance temperaturedetector (RTD) (1k NI, 1k PT,A99B SI)




Resistive Mode, 0–2k ohmBI 4-Dry Contacts UI Dry Contact Maintained

Mode


Table 20: UNT to FX-PCG/FX-PCX Controller point comparison

UNT point type Characteristic FX-PCG/FX-PCXpoint type

Characteristic

BI4-Accum. Input BI Dry Contact MaintainedMode




AO 0 to 10 VDC at 10 mA

UO Voltage Mode, 0–10 VDCBOBO 24 VAC Triac at 0.5 A 1

CO24 VAC Triac 2

RO 24 VAC Relays at 2 A, 13AInrush (Class 2) 3

RO 4 (Single-Pole, Single-Throw:UL 916:1/4 hp 120 VAC

1/2 hp 240 VAC; 360 VA

Pilot Duty at 120/240 VAC(B300); 3 A Non-inductive24-240 VAC; EN 60730: 6 (4)A N.O. or N.C. only

1 UNT11n - Low Side Switching only - UNT14n - Low or High Side Common Selectable2 FX-PCGx611 - Low or High Side switching3 UNT11nn Source sinking or dry contact (jumper selectable per output)4 RO available on FX-PCX2711, FX-PCX3711

RLY Relay Module considerationsRLY relay modules were frequently added to the UNT controller's binary outputs. You can reuse RLYrelay modules when you replace the UNT with an FX-PCG. Each RLY relay module must be wired toone FX-PCG binary or to one configurable output (configured for binary output mode). If both relayson one RLY relay module are used, the FX-PCG controller outputs must be configured identically.Alternatively, you can replace RLY relay modules with FX-PCX models with onboard relay outputs.


Figure 13: Connecting RLY Relay Modules to FX-PCG Controller

Zone bus considerationsUNT controllers support a Zone Bus for optionally connecting TMZ Series network room sensors,TE-77 Series wireless temperature sensor or receivers, a ZTU Zone Terminal Unit, and M100CSeries networked actuators. FX-PC controllers do not support the Zone Bus, and accordingly do notsupport these devices. Instead, FX-PC controllers feature a Sensor Actuator (SA) bus for connectingNS Series Network Sensors, FX-DIS Local Display/Keypad, and FX-PCX Series Expansion I/O Modules.When using an FX-PC controller to replace a UNT controller that uses a TMZ sensor, you must alsoreplace the TMZ sensor with an NS Series Network Sensor. The NS sensor provides many of thesame functions as the TMZ sensor, including zone temperature sensing, zone temperature setpointadjustment, and LCD display. However, the NS sensor is housed in an enclosure that has a differentuser interface. For example, the NS sensor features a dial to adjust the zone temperature setpoint,whereas the TMZ features a pushbutton keypad. As a result, we recommend you work with yourcustomer to help them and their building's occupants understand how to use the adjustmentfeatures of the new NS sensor.When using an FX-PC controller to replace a UNT controller that uses a TE-77xx wirelesstransmitter/receiver, you must also replace the TE-77xx with the Facility Explorer One-to-OneWireless Room Sensing System. For more information, refer to the Facility Explorer One-to-OneWireless Room Sensing System Product Bulletin (LIT-12011664).When using an FX-PC controller to replace a UNT controller that uses a ZTU Zone Terminal Unit, youmust replace the ZTU with an FX-DIS1710 Local Display/Keypad. You can partially duplicate the ZoneTerminal Unit functionality with the FX-DIS1710. However, the FX-DIS1710 does not provide accessto real-time clock functions such as scheduling, trending, and alarming.


When using an FX-PC controller to replace a UNT controller that uses an M100C zone bus actuator,you must replace the actuator with a non-networked actuator. For dampers, use the M9100/M9200Series. For valves, use the VA7800/VA-7150 Series.To control the new actuator, use the available analog output or configurable output interfaces onthe FX-PC controller. If none are available, add an FX-PCX Expansion I/O Module.


Attribute UNT FX-PCG Controller ImplicationNetwork SensorsSupported

TMZ Series Zone Sensors NS Series NetworkSensors

Replace TMZ with NSsensor.


FX-WRZ7860 One-to-OneWireless Sensing System

Replace TE-77 withFX-WRZ7860 One-to-One Wireless SensingSystem.


WRS-TTxx FX-WRZ7860 One-to-OneWireless Sensing System

Replace WRS-TTxx withFX-WRZ7860 One-to-One Wireless SensingSystem.


TE-77 and TE-78 Series TE-77 and TE-78 Series Reusing sensors ispossible.

Note: Someroom sensors(TE-6100-11 and-12, TE-67xx, andTE-67xx) featuredmodular (phone)jack connectionsand requireadaptation for usewith the FX-PCcontrollers.

If you reuse a TE-67xx or TE-68xx series sensor, be aware that the single setpoint or no setpointmodels feature an LED, but the FX-PC controller does not support the LED. As a result, you need tochange the sensor's DIP switch settings as follows:

• If Temporary Occupied function is required for the application, set the DIP switch positionson the back of the sensor to down, up, and down (LED disabled, but Sensor and Push Buttonenabled). The FX-PC controllers do not support the shorting of AI-1 to sense the Temp Occbutton.




Dual setpoint sensor models do not feature an LED. Therefore, you do not need to change the DIPswitch settings.

Control logic configurationRecreating a VMA14xx controller's application that was programmed with HVACPro should bestraightforward. The CCT System Selection Wizard and Sideloop Wizard provide control logiccreation capabilities that are nearly identical to HVACPro's Question and Answer (Q&A) wizard andSideloop wizard.At Release 10.0, the FX-PCV1832 controller featured N2 field bus networking (not switchableto BACnet MS/TP). Also at Release 10.0, pre-built, single-duct VAV box control applications filesreplaced VMA14xx controllers programmed with HVACPro. Those pre-built files contained controllogic translators to make the FX-PCV1832 controller's VAV box control application better resemblethe VMA14xx controller's application created with HVACPro and minimize reconfiguration of the N2supervisor.At Release 10.1, pre-built VAV box control applications are no longer provided. Instead, all controllogic translators provided by the pre-built, single-duct VAV box control application files are nowoptions that you can select using the CCT System Selection Wizard. Select the N2 CompatibilityOptions section of the System Selection Wizard to choose the appropriate replacement application(see Figure 15).


Figure 15: N2 compatibility options

N2 device and point configurationLegacy UNT controllers identify themselves to their N2 supervisor as a UNT device type. The FX-PCG supports identifying itself to its N2 supervisor as a UNT device type, which eliminates the needto change this setting in the N2 supervisor's configuration. To configure this capability, use the N2Mapping feature of CCT as shown in Figure 16.


Figure 16: Compatibility options

Additionally, the CCT System Selection Wizard for the Mixed Air Single Duct Air Handling Unit(MASD) application includes an option to automatically define the N2 mapping table to minimize N2supervisor reconfiguration. All other applications require you to manually create the N2 MappingTable.

N2 Supervisor configurationAs described previously, you can configure the FX-PCG controller to identify itself to an N2supervisor as a UNT device type. If you configure the FX-PCG this way, you do not need toreconfigure the N2 supervisor in this regard.Also, if you configure the MASD application to automatically generate the N2 mapping table, thenyou do not need to reconfigure the N2 supervisor in this regard. However, if the FX-PCG N2 pointmapping does not exactly match its N2 supervisor's point mapping, then you need to reconfigurethe N2 supervisor so that it does. The procedure for performing these changes depends on thetype of N2 supervisor.






For replacements that switch to VND Device Type, point mapping is unrestricted. To make the FX-PCG replacement operation as similar as possible to the old UNT device:




Replacing VAV1xx Variable Air Volume Box ControllersVAV1xx Variable Air Volume Box Controllers were used extensively for controlling VAV boxes, andthey were also frequently used as I/O devices for generic monitoring and control.To replace a VAV1xx controller in a VAV box application, we recommend using the FX-PCV1832controller. To replace a VAV1xx controller in an I/O expansion application, we recommend using theFX-PCG1611 controller.

Footprint comparisonAll models of VAV1xx have a footprint slightly larger than an FX-PCG1611 1 controller. Replacinga VAV1xx with an FX-PCG1611 in an I/O application using the same enclosure space is highlyprobable.When used in a VAV box control application, the VAV1xx is typically connected to an EDA seriesactuator or an ATP series actuator/pressure transducer assembly. You need to replace both theVAV1xx and the EDA/ATP actuator with the FX-PCV1832. The FX-PCV1832 is mounted in place of theEDA/ATP actuator, so this dimensional comparison is key. The FX-PCV1832 is slightly larger than theEDA/ATP. As a result, if you use an FX-PCV1832 to replace a VAV1xx controller plus EDA/ATP actuatorassembly, be sure to verify that enough space is available in the enclosure.


Figure 17: Dimensional Comparison of VAV1xx versus FX-PCG1611

Figure 18: Dimension comparison of VAV1xx versus FX-PCV1832


Figure 19: Dimension comparison of EDA/ATP versus FX-PCV1832

Table 22: Dimensional comparison of VAV1xx versus FX-PCG1611, and FX-PCV1832

Dimension VAV1xx EDA/ATP Actuator FX-PCG1611 FX-PCV1832Height 165 mm (6.5

in.)144.8 mm (5.7 in.) 150 mm (5.9 in.) 165 mm (6.5

in.)Width 163 mm (6.4

in.)101.6 mm (4.0 in.) 164 mm (6.5 in.) 125 mm (4.92

in.)Depth 56 mm (2.2 in.) 59.1 mm (2.3 in.) 54 mm (2.1 in.) 73 mm (2.9 in.)

Wiring connections comparisonTable 23: Wiring connection similarities, differences, and implications

Attribute VAV1xx FX-PCG ImplicationI/O WiringConnectionLocation

See Figure 20. See Figure 20. You can reuse theexisting I/O wiring ifthe existing wiring islong enough to reachthe FX-PCG's I/O wiringconnection points.If not, you need tolengthen the wiring.

Connection Type Spade lug connectors Fixed screw terminalconnectors

Remove spade lugconnectors from I/Owiring.



Attribute VAV1xx FX-PCG ImplicationN2 WiringConnectionLocation

See Figure 20. See Figure 20. You can reuse theexisting N2 wiring if theexisting wiring is longenough to reach the FX-PCG's N2 connectionpoint. If not, you needto lengthen the wiring.

Connection Type Removable, 3-wire screwterminal connector

Removable, 4-wire screwterminal connector

Replace the UNT'sN2 wiring connectorwith the FX-PCG's N2connection point.


See Figure 20. See Figure 20. You can reuse theexisting power supplywiring if the existingwiring is long enoughto reach the FX-PCG's power supplyconnection point. If not,you need to lengthenthe wiring.

Connection Type Spade lug withremovable 2-wire screwterminal connector


Remove existingconnectors from powersupply wiring anduse FX-PCG's screwconnector.

Figure 20: Wiring layout comparison of VAV1xx versus FX-PCG1611



Attribute VAV1xx FX-PCV1832 ImplicationI/O WiringConnectionLocation

See Figure 21. See Figure 21. You can reuse theexisting I/O wiring ifthe existing wiring islong enough to reachthe FX-PCV1832's I/O wiring connectionpoints. If not, you needto lengthen the wiring.

Connection Type Spade lugs Spade lugs No change is necessary,but be careful whenmatching the I/Onumber.


See Figure 21. See Figure 21. You can reuse theexisting N2 wiring ifthe existing wiring islong enough to reachthe FX-PCV1832's N2connection point. If not,you need to lengthenthe wiring.

Connection Type Removable 3-wire screwterminal connector

Removable 4-wire screwterminal connector

Remove connectorfrom the existing N2wiring and use theFX-PCV1832's screwconnector.


See Figure 21. See Figure 21. You can reuse theexisting power supplywiring if the existingwiring is long enoughto reach theFX-PCV1832's powersupply connectionpoint. If not, you needto lengthen the wiring.

Connection Type Spade lug withremovable 3-wire screwterminal connector

2-wire removable screwterminal connector

Remove existingconnectors from powersupply wiring and useFX-PCV1832's screwconnector.


Figure 21: Wiring comparison of VAV1xx versus FX-PCV1832

Point comparisonTable 25: VAV point comparison

Codenumber

Terminationtype

AI BI AO BO RO

VAV110 — 8VAV111

Spade Lug 6 42 6

VAV140 — 8VAV141

ScrewTerminal

6 42 6

—

Table 26: FX-PC point comparison

Codenumber

Termination type UniversalInputs(UI)



RO

FX-PCG1611 Screw Terminal 2 1 4FX-PCV1832 Spade Lug 3

32

— —

FX-PCX2711 Screw Terminal 2—

—

— — 2 2


Table 27: VAV to FX-PCV1832 Controller point comparison

UNT point type Characteristic FX-PCV1832 PointType

Characteristic

AI RTD Temp. Elem.(NI, SI or PT)

0-10 VDCTransducer

2k ohm SetpointPotentiometers

UI Resistance temperature detector(RTD) (1k NI, 1k PT, A99B SI)

Negative temperature coefficient(NTC) (10k Type L, 2.252k Type 2)



Resistive Mode, 0–2k ohmUI Dry Contact Maintained ModeBI 4-Dry Contacts

BI4-Accum. Input BI Dry Contact Maintained Mode

Pulse Counter/Accumulator Mode(High Speed), 100 Hz



AO 0 to 10 VDC at 10mA

UO Voltage Mode, 0–10 VDCBOBO 24 VAC Triac at 0.5

A CO24 VAC Triac

Zone bus considerationsVAV1xx controllers support a Zone Bus for optionally connecting TMZ Series network room sensors,TE-77 Series wireless temperature sensors and receivers, and M100C Series networked actuators.FX-PC controllers do not support the Zone Bus, and accordingly do not support these devices.Instead, FX-PC controllers feature a different technology bus called the Sensor Actuator (SA) bus forconnecting NS Series Network Sensors and FX-PCX Series Expansion I/O Modules.When using an FX-PC controller to replace a VAV1xx controller that uses a TMZ sensor, you mustalso replace the TMZ sensor with an NS Series Network Sensor. The NS sensor provides many of thesame functions as the TMZ sensor, including zone temperature sensing, zone temperature setpointadjustment, and LCD display. However, the NS sensor is housed in an enclosure that has a differentuser interface. For example, the NS sensor features a dial to adjust the zone temperature setpoint,whereas the TMZ features a pushbutton keypad. As a result, we recommend you work with yourcustomer to help them and their building's occupants understand how to use the adjustmentfeatures of the new NS sensor.When using an FX-PC controller to replace a VAV1xx controller that uses a TE-77xx wirelesstransmitter/receiver, you must also replace the TE-77xx with the Facility Explorer One-to-OneWireless Room Sensing System. For more information, refer to the Facility Explorer One-to-OneWireless Room Sensing System Product Bulletin (LIT-12011664).When using an FX-PC controller to replace a UNT controller that uses an M100C zone bus actuator,you must replace the actuator with a non-networked actuator. For dampers, use the M9100/M9200Series. For valves, use the VA7800/VA-7150 Series.To control the new actuator, use the available analog output or configurable output interfaces onthe FX-PC controller. If none are available, add an FX-PCX Expansion I/O Module.



Attribute VAV1xx FX-PCV1832 ImplicationNetwork SensorsSupported

TMZ Series Zone Sensors NS Series NetworkSensors

Replace TMZ with NSsensor.


FX-WRZ7860 One-to-OneWireless Sensing System

Replace TE-77 withFX-WRZ7860 One-to-One Wireless SensingSystem.


WRS-TTxx FX-WRZ7860 One-to-OneWireless Sensing System

Replace WRS-TTxx withFX-WRZ7860 One-to-One Wireless SensingSystem.


TE-77 and TE-78 Series TE-77 and TE-78 Series Reusing sensors ispossible.

Note: Someroom sensors(TE-6100-11 and-12, TE-67xx, andTE-67xx) featuredmodular (phone)jack connectionsand requireadaptation for usewith the FX-PCcontrollers.

If you reuse a TE-67xx or TE-68xx series sensor, be aware that the single setpoint or no setpointmodels feature an LED, but the FX-PC controller does not support the LED. As a result, you need tochange the sensor's DIP switch settings as follows:

• If Temporary Occupied function is required for the application, set the DIP switch positionson the back of the sensor to down, up, and down (LED disabled, but Sensor and Push Buttonenabled).



Dual setpoint sensor models do not feature an LED. Therefore, you do not need to change the DIPswitch settings.


Control logic configurationTable 29: Control logic comparisons

Attribute VAV1xx FX-PCV1832 ImplicationProgramming Tool HVACPro CCT Recreate the VAV's

control logic with CCT.Q/A Session for VAVSingle Duct

System Selection Wizardfor VAV Single Duct

Control Logic


Recreating the VAV'scontrol logic shouldbe straightforward byusing the CCT SystemSelection Wizard orSideloop Wizard.

Downloading Locally through the ZoneBus or N2 Bus usingAS-CVPRO or MM-CVTor remotely using NAEPassthrough

Locally throughSA Bus using FX-BTCVT BluetoothCommissioningConverter

Must be onsite todownload applicationusing CCT.

Zone Terminal Unit considerationsThe VAV1xx controller supported an optional ZTU Zone Terminal Unit, which is not compatibleand cannot be used with FX-PC Controllers. You can partially duplicate the Zone Terminal Unitfunctionality by replacing it with an FX-DIS1710 Local Display/Keypad; however, the FX-DIS1710does not provide access to real-time clock functions such as scheduling, trending, and alarming.

N2 Device and point configurationLegacy VAV1xx controllers identify themselves to their N2 supervisor as a VAV device type. The FX-PCV and FX-PCG support identifying themselves to its N2 supervisor as a VAV device type, whicheliminates the need to change this in the N2 supervisor's configuration. To configure this capability,use the N2 Mapping feature of CCT to set the FX-PCV or FX-PCG controller's device type to VAV.

Figure 23: Using CCT to set the FX-PC Controller's device type to VAV

No utilities are available to automatically recreate the N2 Mapping Table, so you must manuallyrecreate it using CCT.


N2 Supervisor configurationAs described previously, you can configure the FX-PC controller to identify itself to an N2 supervisoras a VAV device type. If you configure the FX-PC controller this way, you do not need to reconfigurethe N2 supervisor in this regard.If the FX-PC controller's N2 point mapping does not exactly match its N2 supervisor's pointmapping, then you need to reconfigure the N2 supervisor so that it does. The procedure forperforming these changes depends on the type of N2 supervisor.





For replacements that switch to VND Device Type, point mapping is unrestricted. To make the CCTcontroller replacement operation as similar as possible to the old VAV1xx device:

• Select a Supervisor Object Type that matches the replaced controller point

• For multi-state objects, select an appropriate States Text table

• Use the Supervisor Object Definition to restrict commands

Replacing AHU Air Handling Unit ControllersAHU controllers were used extensively for controlling air handling units, especially for complexunits requiring more I/O interfaces than the UNT. Many FX-PC controller models can replace anAHU, but we recommend using the FX-PCA3611 because of its onboard I/O complement. If theFX-PCA3611 controller does not have enough onboard I/O to meet the replacement applicationrequirements, then add FX-PCX Expansion I/O Modules.

Footprint comparisonAHUs came mounted in two different configurations: a tower configuration and a three-highUniversal Packaging Module (UPM). If the AHU is a tower configuration, you must replace the entiretower with a new control panel. If the AHU is in a UPM, there should be enough space for an FX-PCA3611. However, you may need to relocate auxiliary gear.The AHU controller's terminal board has a footprint slightly narrower but longer than an FX-PCA3611. Using the same enclosure space for replacement may require you to move auxiliarycomponents, such as limit switches and electro-pneumatic transducers. Also, if an FX-PCXExpansion I/O Module is required to match the AHU's full I/O count, then additional enclosurespace may be required.


Figure 24: Dimensional comparison of AHU versus FX-PCA3611 plus FX-PCX3711

Table 30: Dimensional comparison of AHU versus FX-PCA3611 and FX-PCX3711

Dimension AHU (All Models) FX-PCA3611 FX-PCX3711Height 165 mm (6.5 in.) 150 mm (5.9 in.) 150 mm (5.9 in.)Width 163 mm (6.4 in.) 220 mm (8 7 in.) 190 mm (7.5 in.)Depth 56 mm (2.2 in.) 57.5 mm (2.3 in.) 53 mm (2.1 in.)


Wiring connections comparisonTable 31: Wiring connection similarities, differences and implications

Attribute AHU FX-PCA3611 ImplicationI/O WiringConnectionLocation

See Figure 25. See Figure 25. You can reuse theexisting I/O wiring ifthe existing wiring islong enough to reachthe FX-PCA's I/O wiringconnection points.If not, you need tolengthen the wiring.

Connection Type Fixed screw terminalconnectors

Fixed screw terminalconnectors

Remove spade lugconnectors from I/Owiring.


See Figure 25. See Figure 25. You can reuse theexisting N2 wiring if theexisting wiring is longenough to reach theFX-PCA's N2 connectionpoint. If not, you needto lengthen the wiring.

Connection Type Removable, 3-wire screwterminal connector


Replace the AHU's N2wiring connector withthe FX-PCA.


See Figure 25. See Figure 25. You can reuse theexisting power supplywiring if the existingwiring is long enoughto reach the FX-PCA's power supplyconnection point. If not,you need to lengthenthe wiring.

Connection Type Removable 3-wire Molexconnector


Remove existingconnectors from powersupply wiring anduse FX-PCA's screwconnector.


Figure 25: Wiring layout comparison of AHU versus FX-PCA

Point comparison


AnalogInputs(AI)

BinaryInput (BI)

AnalogOutput(AO)

BinaryOutput(BO)

RelayOutput(RO)

AHU102 Spade Lug 8 8 6 10 –RLY100 4RLY050/002

Cable Kit/ScrewTerminal

– – – –2



AnalogInputs(AI)

BinaryInput (BI)

AnalogOutput(AO)

BinaryOutput(BO)

RelayOutput(RO)

IAPIDP

Uses one AI each

OAP102/103

Note:Replacementrequires oneAC, CO, or UOcombinedwith externalElectro-Pneumatictransducer.

Cable Kit/ScrewTerminal

Mounted in Function Module Kit(FMK102)

M110C Zone Bus

Uses one AO each

Damper and Valve Actuators

Table 32: FX-PCA and FX-PCX Point Comparison

CodeNumber

TerminationType

UniversalInput (UI)

BI AO BO ConfigurableOutput (CO)


RO

FX-PCA2611

6 2 2 –

FX-PCA2612

5 4 –

– – –

5

FX-PCA3611

8 6 6 6 – – –

FX-PCX2711

2 – 2 2

FX-PCX2721

9 2 – –

FX-PCX3711

ScrewTerminals

4

–

–

– –

4 4

Table 33: AHU/FX-PCA/FX-PCX Point Comparison

AHU Point Type Characteristics FX-PCG/FX-PCXPoint Type

Characteristics

AI RTD Temp. Elem. (NI, SI, or PT)

0-10 VDC Transducer

4–20 mA

UI Resistance temperaturedetector (RTD) (1k NI, 1k PT,A99B SI),




Table 33: AHU/FX-PCA/FX-PCX Point Comparison

AHU Point Type Characteristics FX-PCG/FX-PCXPoint Type

Characteristics

UI Dry Contact Maintained ModeBI 0-15 VDC Dry Contacts, TTLthresholds BI Dry Contact Maintained Mode


AO Current Mode, 4–20 mA

Voltage Mode, 0–10 VDCCO Voltage Mode, 0–10 VDC

AO 0-10 VDC at 10 ma

0-10 VDC (using 500 ohmresistor)

Zone Bus (up to sixM110CGA-2 actuators)

UO Analog Output, Voltage Mode,0–10 VDC

Analog Output, Current Mode,4–20 mA

BOCO

24 VAC Triac

Note: All Triac configuredBO and UO outputsare electrically isolated(capable of switchingHigh or Low side).

BO 24 VAC Triac at 0.5 A

UO Binary Output Mode, 24 VAC/DC FET

RO Optional relay kit 240 VAC at 5amps

RO Single-Pole, Single-Throw: UL916:1/4 hp 120 VAC, 1/2 hp240 VAC; 360 VA

Pilot Duty at 120/240 VAC(B300); 3 A Non-inductive24-240 VAC; EN 60730: 6 (4) AN.O. or N.C. only

RLY Relay Module considerationsRLY relay modules are frequently added to the AHU controller's binary outputs. You can reuse RLYrelay modules when replacing the AHU with an FX-PCA3611. You must wire each RLY relay moduleto one FX-PCA3611 binary or to one configurable output (configured for binary output mode).If both relays on one RLY relay module are used, you must configure the FX-PCA3611 controlleroutputs identically. Alternatively, you can replace RLY relay modules with FX-PCX models withonboard relay outputs.


Figure 26: Connecting RLY Relay Modules to FX-PCA3611 Controller

Function Module (FMK) considerationsAHU controllers frequently used FMK Function Modules to provide input and output interfaces.Follow these guidelines when replacing the AHU controller and FMK Function Modules:

• Each input function module (IAP, IDP) must be wired to one FX-PCA/FX-PCX set for current mode.

• Each output function module (OAP) must be wired to one FX-PCA/FX-PCX AO or UO set for currentmode.

• Optionally, FMK modules may be replaced by equivalent products. (For example, replaceOAP102/103 with EP-8000.)

• When selecting transducers to replace OAP and OSV Function Modules, be sure to match thetransducer output pressure range (psig or kPa) and volume (SCIM or SCCM) to the demands ofthe actuator.

Zone bus considerationsAHU controllers supported a Zone Bus for connecting M100C Series networked actuators. FX-PCcontrollers do not support the Zone Bus, and accordingly do not support these devices. When usingan FX-PC controller to replace an AHU controller that uses an M100C zone bus actuator, you mustreplace the actuator with a non-networked actuator. For dampers, use the M9100/M9200 Series.For valves, use the VA7800/VA-7150 Series.To control the new actuator, use the available analog output or configurable output interfaces onthe FX-PC controller, or, if none are available, add an FX-PCX Expansion I/O Module.


Zone Terminal Unit considerationsThe AHU controller supported an optional ZTU Zone Terminal Unit, which is not compatible andcannot be used with FX-PC controllers. You can partially duplicate the Zone Terminal functionalityby replacing it with an FX-DIS1710 Local Display/Keypad; however, the FX-DIS1710 does not provideaccess to real-time clock functions such as scheduling, trending, and alarming.

Control logic configurationTable 34: Control logic comparisons

Attribute AHU FX-PCA ImplicationProgramming Tool HVACPro CCT Recreate the AHU's

control logic with CCT.Q/A Session for mixedair single path, mixed airdual path, 100% outsideair single path, 100%outside air dual path

System Selection Wizardfor mixed air single duct,mixed air dual duct,100% outside air singleduct, 100% outside airdual duct

Control Logic


Recreating the AHU'scontrol logic shouldbe straightforward byusing the CCT SystemSelection Wizard orSideloop Wizard.

Downloading Locally through the ZoneBus or N2 Bus usingAS-CVPRO or MM-CVTor remotely using NAEPassthrough

Locally throughSA Bus using FX-BTCVT BluetoothCommissioningConverter

Must be onsite todownload applicationusing CCT.

N2 device and point configurationLegacy AHU controllers identify themselves to their N2 supervisor as an AHU device type. The FX-PCA3611 supports identifying itself to its N2 supervisor as an AHU device type, which eliminates theneed to change this setting in the N2 supervisor's configuration. To configure this capability, usethe N2 Mapping feature of CCT to set the FX-PCA controller's device type to AHU.Additionally, the CCT System Selection Wizard for the Mixed Air Single Duct Air Handling Unit(MASD) application includes an option to automatically define the N2 mapping table to minimize N2supervisor reconfiguration. All other applications require you to manually create the N2 MappingTable.

N2 Supervisor configurationAs described previously, you can configure the FX-PCA3611 controller to identify itself to an N2supervisor as an AHU device type. If you configure the FX-PCA3611 this way, you do not need toreconfigure the N2 supervisor in this regard.Also, if you configure the MASD application to automatically generate the N2 mapping table,then you do not need to reconfigure the N2 supervisor in this regard. However, if the FX-PCA3611N2 point mapping does not exactly match its N2 supervisor's point mapping, then you needto reconfigure the N2 supervisor so that it does. The procedure for performing these changesdepends on the type of N2 supervisor.






For replacements that use the AHU Device Type, the following point mapping restrictions must beobserved.

• The range of allowable Point Addresses for each mapped Network Point Type is restricted.

• CCT N2 Point Mapping tool does not enforce these restrictions; an application could beconfigured with CCT that results in points that cannot be mapped into an N2 supervisor.

• Many of the allowed ADF, ADI, and BD Point Addresses are Read Only, meaning no commandingis allowed.

Demolition and disposalBefore disposing of legacy N2 controllers, consider the following:

• Many legacy N2 controllers may be salvageable. Check with the Johnson Controls Repair Centerbefore disposing.

• Follow all state and provincial laws regarding disposal of electronic components.

• Dispose of all removed components in an environmentally sensitive manner.

Converting to BACnet MS/TP field busCCT 10.1 includes the ability to configure the field bus networking protocol to be N2 or BACnet MS/TP. The previous sections of this document describe how you can use this feature to help supportlegacy N2 controller installations by providing a replacement strategy using FX-PC controllersconfigured for N2 field bus networking. You can also use this selectable protocol feature to providea cost-effective, field bus modernization strategy. Once you have replaced several of the legacy N2controllers with N2-configured FX-PC controllers, and your N2 supervisor also supports managingBACnet MS/TP field bus networks, you may want to consider reconfiguring the FX-PC controllers touse BACnet MS/TP field bus networking to gain a modern, higher performance field bus.From a sequence-of-operation perspective, FX-PC controllers operate the same whether they areconfigured for N2 or for BACnet MS/TP; however, some differences should be considered beforeproceeding. This section of the document describes the key differences between using FX-PCcontrollers on an N2 field bus network versus on a BACnet MS/TP field bus network to help youprevent, minimize, and overcome installation and configuration challenges.

Device addressingN2-configured FX-PC controllers support the full range of possible N2 device addresses supportedby the N2 protocol standard (1-255); however, BACnet-configured FX-PC controllers only supportaddresses 4-127. When switching the FX-PC controllers from N2 to BACnet MS/TP, you may need tochange your network's device addressing scheme to accommodate this limitation.


Control configuration for BACnet MS/TPWhen you are ready to move to a BACnet MS/TP configuration, use CCT to switch the FX-PCcontrollers' field bus network to BACnet MS/TP and then re-download the controller application files(*.caf) to the desired FX-PC controllers.As you convert FX-PC controllers to BACnet MS/TP, we recommend that you keep the controllersdisconnected from the Field Controller (FC) Bus network until all have been converted to BACnetMS/TP and the supervisory controller has been reconfigured for BACnet MS/TP. Follow these stepsto convert N2-configured FX-PC controllers to BACnet MS/TP:

1. Disconnect the FC Bus connector from the FX-PC controller.

2. Ensure there is 24 VAC supply to the FX-PC controller.

3. Use CCT and an SA bus connection to upload the FX-PC controller's application file.

4. Clear the N2 Mapping Table and save the application file.

5. Disconnect the 24 VAC supply from the FX-PC controller.

6. Set the address switch to the desired BACnet MS/TP address. See Device addressing for detailsabout N2 and BACnet MS/TP device addressing.

Note: When configured for BACnet MS/TP, the address switch segment labeled 128establishes the FX-PC controller for wireless mode. If you are not intending on using theFX-PC controller in a wireless network, then set the 128 segment to OFF.

7. Connect the 24 VAC supply to the FX-PC controller.

8. Using the CCT tool and an SA bus connection, download the BACnet-configured application tothe FX-PC controller.

9. When the download process asks to confirm switching the communication protocol to BACnet,click Accept.

10. Reconnect the FC Bus connector to the FX-PC controller.

Reusing existing N2 wiring for BACnet MS/TPWhen converting FX-PC controllers from N2 to BACnet MS/TP, you may encounter some challengeswith reusing the existing field bus network wiring. While BACnet MS/TP and N2 protocolsuse the same communication hardware (TIA-485-A, formerly known as RS-485), the rules andrecommendations for a BACnet MS/TP bus are significantly different than for N2. The guidelinesin this section should be followed when planning to convert an existing N2 field bus network toBACnet MS/TP.N2 network wiring guidelines have changed over time. The most recent recommendationestablishes 22 AWG or heavier as the preferred size, but still allows for 18 through 26 AWG wire.Your customer's network may use a variety of these wiring options, depending on when eachnetwork segment was installed. Wire gauge recommendations are different for BACnet MS/TP.BACnet MS/TP network guidelines recommend 22 AWG wire.N2 network uses 9600 baud rate. BACnet MS/TP can be configured for up to 76.8k baud. The higherbaud rates of BACnet MS/TP may not run efficiently on 18 AWG cable. Also, electrical impedancecharacteristics of the wire degrade the signals.Johnson Controls engineering conducted extensive tests using 3-wire 18 AWG cable, and they foundnegligible performance variation with the shield-terminated test versus the unterminated testand negligible performance improvement by reducing the number of devices on a segment at aparticular baud rate.


Table 35: Recommended network wiring for BACnet MS/TP using 3-wire 18 AWG cable

Baud rate Devices Segment length (ft.) Offline or onlinealarms

Errors

76.8k 50 2,000 0 138.4k 50 4,000 0 019.2k 50 5,000 0 19600 50 5,000 0 0

Consider the following workaround options, and select the most appropriate options based on yourspecific installation situation:

• Use repeaters, placed at closer intervals to boost the signal

• Reduce the BACnet MS/TP baud rate

• Replace long N2 network cable runs with wireless routers

• Use Wireless Field Bus connections to alter the network configuration

• Replace long N2 network cable runs with BACnet MS/TP recommended cable

• Use fiber-optic modems between network segments

• Use protocol converter devices to manage the network


© 2019 Johnson Controls. All rights reserved. All specifications and other information shown were current as of documentrevision and are subject to change without notice.

Documents

Modernization Guide for N2 Controllers - Facility Explorer