Operations Maintenance Manual - Sutron Corporation · Sutron Corporation ModbusLinkPlus Rev. C Operations & Maintenance Manual 12/15/2016 pg. 4 1. Introduction ModbusLinkPlus is an

ModbusLinkPlus

Operations & Maintenance Manual

Part No. 8800‐1197 Revision – C

October 27, 2016

Sutron Corporation ModbusLinkPlus Rev. C Operations & Maintenance Manual 12/15/2016 pg. 2

TABLE OF CONTENTS

1. Introduction ..................................................................................................................................... 4

1.1 Features .............................................................................................................................. 4

2. Unpacking ........................................................................................................................................ 5

3. Hardware ......................................................................................................................................... 6

3.1 Power Connector ................................................................................................................ 6

3.2 LEDs .................................................................................................................................... 7

3.3 Terminal Block Description................................................................................................. 7

4. Setup and Operation ........................................................................................................................ 8

4.1 Configuration as a ‘Gateway’ or ‘Remote Node’ ............................................................... 8

4.2 Modbus Registers ............................................................................................................... 8

4.3 Input Registers (Live Readings) .......................................................................................... 8

4.4 Holding (Read/Write) Registers ........................................................................................ 10

4.5 Polled Measurements ...................................................................................................... 12

4.6 Diagnostic Commands ...................................................................................................... 12

4.7 Scheduled Measurements (Pushed Data) ........................................................................ 13

4.8 Setup ................................................................................................................................ 14

4.9 Network Setup ................................................................................................................. 14

4.10 Analog Sensor Setup......................................................................................................... 14

4.11 Single Ended Analog Inputs 0‐4v (VA, VB) ........................................................................ 15

4.12 Differential Voltage Input (Diff C, Diff D, Diff E) ............................................................... 15

4.13 Digital Inputs (WS/DIG IN1 / TB DIG CH2) ....................................................................... 16

4.14 Frequency Measurement ................................................................................................. 17

4.15 Counter/Tipping Bucket ................................................................................................... 17

4.16 Voltage Level‐ Digital Sensors .......................................................................................... 17

4.17 SDI‐12 Sensor Input .......................................................................................................... 17

4.18 RS232/RS485 Port, Wake Input ........................................................................................ 18

5. ModbusLink Network Basics........................................................................................................... 19

6. Troubleshooting and Maintenance ................................................................................................. 22

6.1 Troubleshooting ............................................................................................................... 22


6.2 Maintenance .................................................................................................................... 22

Appendix A ......................................................................................................................................... 23

Writing Holding Registers Using XPert ........................................................................................... 23

Appendix B .......................................................................................................................................... 25

Firmware Upgrade .......................................................................................................................... 25

Appendix C .......................................................................................................................................... 26

FCC and IC Certification .................................................................................................................. 26

Appendix B .......................................................................................................................................... 27

Specifications .................................................................................................................................. 27

Ordering .......................................................................................................................................... 28

Appendix D ......................................................................................................................................... 29


1. Introduction

ModbusLinkPlus is an ultra‐low power wireless node, fully compatible with Sutron’s ModbusLink wireless sensor network (WSN) family. The ModbusLinkPlus can measure up to two single ended analog sensors, three differential analog sensors, two SDI‐12 sensors, and two digital inputs. The ModbusLink family is Sutron’s proprietary ultra‐low power, self‐healing, ad‐hoc mesh network, optimized to provide years of service and using only an internal lithium battery. The ModbuslinkPlus module can also be programmed to automatically measure sensors periodically. The scheduled measurement data is automatically pushed to the Gateway. If no ack is received, the data will be retransmitted after completion of the next scheduled measurement.

A ModbusLink network consists of one ‘Gateway’ connected to a Modbus Master/Logger/Data Recorder and at least one ‘Remote Node’. A ModbusLinkPlus or ModbusLink‐M module can be used as a ‘Gateway’. A ModbusLinkPlus configured as a slave or a ModbusLink(s) can be used as ‘Remote Nodes’.

1.1 Features

1 mile LOS range ( longer ranges possible via intermediate nodes/mesh networking)

Very low power consumption.

All ‘Slave Nodes’ are fully functional and capable of routing messages, while staying in low power mode

5 years battery life (included)

RSSI level indication to indicate Signal strength.

Multiple Networks can co‐exist without interfering with each other.

Simple Modbus commands to configure, maintain network

3 independently programmable switched +12v power supplies


2 single ended analog inputs ( programmable gain)

3 differential analog inputs (programmable gain)

2 digital inputs, configurable to measure frequency or counts with programmable debouncing.

2 SDI‐12 sensors

Programmable Measurement Scheduler automatically measures Sensors and pushes data to Gateway.

Un‐Acked Pushed data is stored onboard.

Stored data is automatically pushed to the Gateway in response to Acks

2. Unpacking

Remove the ModbusLink Plus unit from the shipping container and visually inspect the unit for signs of damage during shipment. Report any such damage to the factory immediately to ensure a prompt response and resolution. Retain one shipping container in the event a factory return is necessary.

Please note that if a return is required, a return material authorization (RMA) number is required. To get this RMA number, call the Sutron Customer Service Department at 703 406 2800.


3. Hardware

3.1 Power Connector

The Module can be powered by an external (8v ‐ 20v) battery or the internal battery (3.4v to 13v). The external battery must be wired to the terminal block. A 2‐pin connector on the right side of the ModbusLinkPlus can be used to power the unit off a lithium battery. If both batteries are connected, ModbusLinkPlus will select the higher of the two voltage sources. If one of the sources fails, ModbuslinkPlus will seamlessly switch to the other source without interrupting operation. The performance/functionality of the module is identical, regardless of the power input source.


3.2 LEDs

Three LEDs provide an indication to the current state of ModusLinkPlus module. A green ‘status’ LED blinks

every 5 seconds to indicate normal operation. If errors are present, the ‘status’ LED will blink red instead.

The Modbus command table provides a description of various error conditions that can be reported by the

ModbusLinkPlus module. In addition, the module also has an orange LED to indicate RF activity. RF activity

indicates that the module is either sending or receiving an RF packet.

3.3 Terminal Block Description

Pin Number/Label Description

1. GND Ground Terminal for external battery

2. EXT BATT 8v‐16v DC power supply input

3. GND Ground Terminal for RS232/RS485 Modbus Port

4. SW’D +12 Programmable Switched 12v supply for Modbus Sensors( Future use)

5. RXD/485 A Modbus Rx Terminal/ RS485‐A

6. TXD/485 B Modbus Tx terminal/ RS485‐ B

7. DTR/Wake Wakes interrupt for Modbus Port. Tie this pin HIGH to keep the Modbus port active

8.WS/DIG IN 1 Frequency input/ Digital input (TPG or position ) Channel 1

9. GND Ground Terminal ( WS/Digital)

10.WS/DIG IN 2 Frequency input/ Digital input (TPG or position ) Channel 2

11. SW’d +12 Programmable Switched 12v for powering Digital sensors

12. GND GND terminal for SDI‐12 Sensor

13. SW’D +12 Programmable Switched +12v supply for powering SDI‐12 sensor

14. DATA SDI‐12 Data bus

15. DIFF E+ Positive input of Diff E pair

16. DIFF E‐ Negative input of Diff E pair

17. GND Ground terminal for Diff E pair

18. VREF (2.5v) 2.5v Reference voltage for analog sensors

19. DIFF D+ Positive input of Diff D pair

20. DIFF D‐ Negative input of Diff D pair

21. GND Ground terminal for Diff C pair

22. DIFF C+ Positive input of Diff C pair

23. DIFF C‐ Negative input of Diff C pair

24. VREF (2.5v) 2.5v Reference voltage for analog sensors

25. GND Ground terminal for Diff E pair

26. SW’d +12 Programmable Switched 12v for powering Analog sensors

27. ANALOG B Single ended analog input B

28. ANALOG A Single ended analog input A


4. Setup and Operation

4.1 Configuration as a ‘Gateway’ or ‘Remote Node’

The ModbusLinkPlus module can be configured as a Gateway or a Remote Node via Modbus commands. To connect the ModbuslinkPlus module to a PLC/Data logger, the module must be configured as a ‘Gateway’. Each ModbuslinkPlus module in the same network must be assigned a unique ‘Node Address’ that is used to identify that node in the Network. In order to connect to a Modbus Master/Logger via either the RS232 or the RS485 port, the ModbusLinkPlus module must be configured as a ‘Gateway’ by configuring the Node Address to 50 (0x32). Any other address value configures the module as a remote node.

The Modbus communication port (RS232/RS485) is managed by software. The port is automatically turned off when not in use, however tying the WAKE pin HIGH prevents the port from being turned off. If a PLC/Logger wants to send Modbus command to the logger, the ‘Wake’ pin must be pulled HIGH. The port will remain open as long as the ‘Wake’ pin is tied HIGH. This could be useful for configuring the remote node using a direct RS232/RS485 connection. The DTR pin on most RS232 interfaces can be used as the ’Wake’ input. All features of the ModbusLinkPlus are available via the Modbus Port.

4.2 Modbus Registers

All measurements supported by the ModbusLinkPlus are mapped to Modbus registers in memory. Input (Modbus) registers are read only registers that can be read using Function code 0x04. When reading or writing registers, the number of registers read or written to must always match the table(s) below. If the register count does not match the expected value, an error code will be returned. This safety check, ensures that registers are not accidently corrupted or overwritten.

Holding registers are read/write registers that can be read using function code 0x03 and written using function code 0x16. Input registers are used to initiate a measurement and retrieve the result, while Holding registers can be used to read/write configuration parameters, read/write certain measurement values (like TPG count) or perform certain actions (factory reset, reboot system).

All measurements have been grouped into one of four categories (Digital, Analog, SDI‐12 or RS232/RS485). Each category has its own independently switched +12v supply that can be used to power (warm up) sensors in that group. The switched supply for each category can be independently programmed to power the sensors (between 0s to 30s) before making a measurement. After making a measurement, the switched supply will be automatically turned off to conserve power.

4.3 Input Registers (Live Readings)

All measurements (including diagnostics) are mapped to unique modbus registers. Some measurements can be scheduled to be automatically executed periodically. The ModbuslinkPlus will sequentially perform all scheduled measurements and pack the data with a time stamp. Measurements that can be scheduled are indicated by a in the table below.


REG ADDR REG CNT DESCRIPTION SCHED

0 2 Live measure Analog Input Channel VA

1 2 Live measure Analog Input Channel VB

2 2 Live measure Analog Input Channel DIFF‐C

3 2 Live measure Analog Input Channel DIFF‐D

4 2 Live measure Analog Input Channel DIFF‐E

5 1 Live measure SDI Sensor #1 and update Cache Sensor param data array.

6 2 Cached data SDI sensor #1, Param #1





12 1 Live measure SDI Sensor #2 and update Cache Sensor param data array.




16 28 Scheduled Measurements Data

17 10 Read Node Diagnostic information(1)

18 19 Live Network Scan(2)

19 1 Last Message RSSI

20 2 Live measure Auxiliary battery voltage


4.4 Holding (Read/Write) Registers

Holding registers are read/write registers that can be used to configure or set certain registers. Function code 0x03 must be used to read the holding register, code 0x16 enables writing to a register. If a PC is used to configure the modules, any PC based utility ( for eg. Baseblock ComTest Pro) can be used. The ‘Wake/DTR’ pin will have to be tied High at power up. The Appendix has a detailed description about how to write holding registers using Sutron’s Xpert data logger.

REG ADDR REG CNT READ/WRITE DESCRIPTION

RANGE DEF. VAL

0 1 R/W Node Address 1…50 1

1 1 R/W Network ID 0…13 13

2 1 R/W Measurement Schedule in seconds 60…3600 900

3 4 R/W System Time(3)

4 1 W Delete log (Key = 0xA1A1) 0xA1A1

5 4 W Pushed Data Ack(4)

6 1 R/W Analog Measurements Warmup (seconds) 0…30 1

7 1

R/W

Enable/Disable Analog Channel VA (scheduled meas)

0…1 0(disabled)

8 1 R/W Analog Channel VA measurement gain(5) 0…6 0

9 1

R/W

Enable/Disable Analog Channel VB (scheduled meas)

0…1 0(disabled)

10 1 R/W Analog Channel VB measurement gain(5) 0…6 0

11 1

R/W

Enable/Disable Analog Channel DIFF‐C(scheduled meas)

0…1 0(disabled)

12 1 R/W Analog Channel DIFF‐C measurement gain(5) 0…6 0

13 1

R/W

Enable/Disable Analog Channel DIFF‐D(scheduled meas)

0…1 0(disabled)

14 1 R/W Analog Channel DIFF‐D measurement gain(5) 0…6 0

15 1

R/W

Enable/Disable Analog Channel DIFF‐E(scheduled meas)

0…1 0(disabled)

16 1 R/W Analog Channel DIFF‐E measurement gain(5) 0…6 0

17 1 R/W SDI Measurements Warmup (seconds) 0…30 1

18 1 R/W SDI Sensor #1 Address

‘0’…’9’ ‘a’…’z’ ‘A’…‘Z’

‘0’

19 1

R/W

Enable/Disable SDI #1 Param1 (scheduled meas)

0…1 0(disabled)


20 1

R/W


0…1 0(disabled)

21 1

R/W


0…1 0(disabled)

22 1

R/W


0…1 0(disabled)

23 1

R/W


0…1 0(disabled)

25 1 R/W SDI Sensor #2 Address

‘0’…’9’ ‘a’…’z’ ‘A’…‘Z’

‘1’

26 1

R/W


0…1 0(disabled)

27 1

R/W


0…1 0(disabled)

28 1

R/W


0…1 0(disabled)

29 1 R/W Digital Measurements Warmup (seconds) 0…30 1

30 2

R/W Read/Write Dig Channel 1 Input (Write only for counter configuration.

31 1 R/W Enable/Disable Digital CH#1 (scheduled meas) 0…1 0(disabled)

32 1 R/W Digital Ch#1 Sample Duration (ms) (6) 0…10000 500

33 1

R/W Read/Write Channel 1 Pull direction 0…1 0 = Pull Down,

1 = Pull up

34 2

R/W Read/Write Dig Channel 2 Input (Write only for counter configuration.

35 1 R/W Enable/Disable Digital CH#1 (scheduled meas) 0…1 0(disabled)

36 1 R/W Digital Ch#1 Sample Duration (ms) (6) 0…10000 500

37 1

R/W Read/Write Channel 2 Pull direction 0…1 0 = Pull Down,

1 = Pull up

38

1

W Reboot /Factory Reset

0=REBOOT 0xA1A1=RESET

2 byte value decides operation

39 1 W Emergency Reboot Destination Node 1…50

40 1 W Destination Node Address for Query command 1…50

41 20 R Destination Route/RSSI Query (7)

42 1 R/W Modbus port baud rate(7) 0…5 0

43 1 R/W Upgrade Firmware on Remote node(8) 1…50 N/A


4.5 Polled Measurements

Reading any Modus input register assigned to an input will force a new measurement (except cached SDI parameter registers) and return the data back as a regular Modbus response. The warmup parameter configured for each group (Analog, Digital and SDI) of sensors should be considered when programming the timeout parameter on the logger. The ModbusLinkPlus also supports diagnostic commands that can be polled as regular Modbus commands.

4.6 Diagnostic Commands

The ModbusLinkPlus supports the following diagnostic commands to query the status of an individual node and also query network parameters.

The Node Diagnostics command (Input register # 10) returns the firmware version for various software modules, total packet count and dropped packet count. The response is packed in a binary structure (NODE_DIAG)

Byte Cnt Description

4 Application version (IEEE 754 floating point)

4 Network Stack Version(IEEE 754 floating point)

4 Modbus Stack Version(IEEE 754 floating point)

2 Total Packet Count

2 Dropped Packet Count

2 Reserved

The Network scan command (0x14) performs a scan global scan and returns all nodes that are part of the network. The Network scan command takes about 30s to complete. The response is packed as a binary structure NETWORK_QUERY_DATA

Byte Cnt Description Range

1 Command ID 1= Network Scan Results 2= Route query Results

1 Num of address’s in address payload 0…36

36 Address payload Array(1 byte per address) Array contains a list of all node address

(7) The ModbuslinkPlus supports commands that can be used to query the route and the RSSI to a destination node address. The command returns the complete path and RSSI for each intermediate node to the destination node. The process of querying the route to a destination node consists of 2 parts.

1) Write the destination address to holding register # 88.

2) Start the Query process by reading Input register #36


The response is packed as a binary structure NETWORK_ROUTE_RSSI_DATA


1 Command ID 2= Route query Results

1 Num of address’s in address payload 0…17

1 Node Address Hop#1 Array contains a path to the destination Node. 1 byte node address followed by 2 bytes of RSSI informationj

2 Rssi as seen by current Node (address in previous byte)

0…83

1 Node Address Hop#2 Array contains a path to the destination Node. 1 byte node address followed by 2 bytes of RSSI informationj

2 Rssi as seen by current Node (address in previous byte)

0…83

The last received message RSSI can by queried by reading Input Register # 0x15. The value is a 2‐byte integer value between 0 and 83 that represents the Energy level (ED_LEVEL) in the received signal. The RF power can be calculated by using the formula

RF Power (dBm) = ‐94 dBm * ED_LEVEL

For reliable communication, an Energy level higher that 15 dBm is required.

4.7 Scheduled Measurements (Pushed Data)

The Modbuslink can be programmed with a measurement interval (Holding Register #2) to automatically measure enabled sensors at a fixed period. If atleast one sensor is enabled, a write command to Holding register #3 (system time) starts the measurement scheduler. The System time must be packaged as a binary structure (TIME_STRUCT) described below. The measurement interval is calculated from the top of the hour.

TIME_STRUCT


2 Year (unsigned integer)

1 Zero based Month 0…11

1 Zero based Day 0…30

1 Zero based Hour 0…22

1 Zero based Minutes 0…58

1 Zero Based Seconds 0…58


All enabled sensors are measured sequentially in the order in which they appear in table xx. After completion of the last measurement, the data is pushed to the logger via the Gateway. The Pushed data is formatted as a response to a Read Input Register #18 (0x12) command. The data format for the pushed packet is described in section NODE_PUSHED_DATA described below. The pushed data packet includes a time stamp (TIME_DATA). On receiving pushed data, the logger must send an ACK back to the node from which it received the data. The format of the Ack Packet is identical to the format of the System Time command and must be match the time stamp contained in the Pushed packet being Acked.

NODE_PUSHED_DATA

Byte Cnt Description

2 CRC cyclic redundancy check

7 TIME_DATA

1 Payload byte count

40 Sensor value (maximum of 10 values in IEEE 754 floating point)

If no Ack was received when the next scheduled measurement cycle completes, the new data is stored to the internal log chip and the old Un‐Acked packet is resent. If an ACK is successfully received by the original node, the time‐stamp in the Ack packet is compared to time stamp that was sent as part of the pushed data. If the time stamps match, the node checks its log chip for any pending data.

4.8 Setup

4.9 Network Setup

A modbuslink network can be modified/setup by writing to 2 modbus holding register (Node address register, Network ID registers). Each ModbusLinkPlus module in a network must have a unique node address. The Node address can be set by writing to the new address value to holding register (register address 0x00). Setting the node address to a value 0x32 configures the module to act as a ‘Gateway’. The Network ID can be modified by writing to the holding register at address 0x01. All ModbusLinkPlus modules (within radio range) that share the same Network ID can communicate with each other.

4.10 Analog Sensor Setup

The ModbusLink Plus module supports two single ended 0‐4v analog sensors and 3 differential sensors. The analog module has a 2.5 reference output for sensors that need a precise reference voltage and a programmable switched +12v supply that can be used to power analog sensors.

Analog Channel Range Configuration

Register Value Input Range

0 1.5v*


1 1.25v*

2 625mv*

3 312 mv*

4 156mv*

5 78mv*

6 39mv*

7 19mv*

*Input Ranges with low end input (‐) tied to VRef (2.5v)

4.11 Single Ended Analog Inputs 0‐4v (VA, VB)

Inputs 0‐4V A and 0‐4B are designed to be general purpose 0‐4 Volt DC input. While sometimes referred to as a single ended input, it is designed to measure voltage with respect to analog ground. These inputs have a high impedance (>2 Meg Ohms) and will not load down or draw significant current. The input range is 0V to 4V. Negative voltages with respect to AGND may NOT be measured on these inputs.

To connect a sensor:

The voltage output by the sensor should be connected to either A or B.

The analog ground from the sensor needs to be connected to AGND.

The sensor will likely require power – connect that to VREF if 2.5V is appropriate or to +SW POWER which is 12V (or whatever power ModbusLinkPlus is supplied with).

Make sure to set up the warmup (the amount of time to power the sensor before reading its output) as required by the sensor.

If the sensor has a power ground, connect that to AGND.

4.12 Differential Voltage Input (Diff C, Diff D, Diff E)

Measurements Diff C, Diff D and DIFF E are designed to operate with a special type of analog output found on many sensors that use a bridge configuration or any sensor that outputs a very small voltage. This input type has a + and ‐ input that connects to the sensor output.


Typically, a bridge sensor will be powered on VREF (sometimes referred to as excitation), have a signal + and signal –, and provide a wire for the analog ground. NOTE: If after wiring the sensor, it displays a negative reading, you may reverse the + and ‐ leads coming from the sensor.

Typically a bridge sensor will be powered on “VREF” (sometimes referred to as excitation), have a “signal +” and “signal –“, and provide a wire for the analog ground. NOTE: If after wiring the sensor, it displays a negative reading, you may reverse the “+” and “‐“ leads coming from the sensor.

4.13 Digital Inputs (WS/DIG IN1 / TB DIG CH2)

ModbusLinkPlus has 2 digital input channels that support the following types of digital inputs:

o Frequency

o Counter/Tipping bucket

o Level digital sensors

Each Digital channel can be independently configured to measure any of the above sensor inputs. The digital module has a programmable switched +12v supply that can be used to power digital sensors.


4.14 Frequency Measurement

Setting the measurement interval to a non‐zero value configures the input for frequency measurement.

Frequency measurement can be used to measure sensors that output a frequency like a RM Young sensor.

The ModbusLink Plus module will sample the input for the measurement interval and provide a result that is the average frequency of the input during that time span. If no signals are noticed on the input during the time, the measurement is considered bad.

4.15 Counter/Tipping Bucket

Setting the measurement interval to zero configures the input for counting transitions. The input can be configured to increment the counter either on a falling edge or rising edge. A pull‐up or pull‐down is automatically enabled based on the selected edge.

The current count can be read by reading a single holding register. The count is automatically reset to zero at power‐up. The count can also be set to a fixed value (or zero) by writing the desired value to the same holding register.

A debouncing interval can be programmed (holding register) for each channel to reduce the effects of switching/transient noise.

4.16 Voltage Level‐ Digital Sensors

The two digital input channels can be used measure Level digital inputs (read line state as 1 or 0). Regardless of whether the Digital Input is configured to measure frequency or as a counter, the current pin state can be read by reading the appropriate input register (Register# 602 for channel 1 or register # 606 for channel 2). A value of 1 indicates that the current pin state is high, 0 indicates a low state.

4.17 SDI‐12 Sensor Input

The ModbusLinkPlus module can be configured to measure up to two SDI‐12 sensors. Each SDI Sensor must have a unique SDI address as per the SDI‐12 protocol. The SDI address for each of the two SDI sensors can be configured by writing to holding register #18 and register #25.

All SDI‐12 communication begins with the SDI‐12 master issuing an SDI‐12 command. The command can either be a measure command (‘M’ command), a concurrent command (‘C’ command) or a continuous measure command (‘R’ command). In addition to these commands, some sensors may support custom commands known as extended commands.

The current version of the ModbusLink Plus firmware only supports ‘M’ commands. An SDI‐12 measure command consists of an SDI‐12 address and the measurement number (for eg. “0M1!” instructs sensor with address ‘0’ to initiate measurement ‘M1’). The addressed sensor should then reply with the number of parameters that will be returned and the time required complete the measurement. Once the time has elapsed, the SDI‐12 master should issue a read command (‘D’ command) to read the results. Please refer to www.sdi‐12.org for a detailed description of the SDI‐12 protocol.


The ModbusLinkPlus module implements the complete SDI‐12 protocol stack to handle all the necessary commands and timing constraints to query an SDI‐12 sensor and collect the response. Each parameter returned by the sensor is automatically stored in the appropriate modbus register (refer Table: 2). All parameters are stored as 4 byte (2 modbus registers) float values.

Each SDI sensor has an input register that forces a live measurement (M‐Command) and populates the ‘Param’ registers in its group with the data received from the sensors. Reading the ‘Param’ register will NOT perform new measurement.

The SDI‐12 module has a programmable switched +12v supply that can be used the SDI‐12 sensors.

4.18 RS232/RS485 Port, Wake Input

The ModbusLinkPlus module has an RS232/RS485 port that can be used to interface with a data logger (Modbus master). Either the RS232 or the RS485 port can be activated by writing to the appropriate holding register. If the ModbusLink Plus module is configured as a ‘Gateway’ (to interface with a data logger), it accept Modbus commands over the RS232/RS485 port. If the module is not configured as a ‘Remote Node’, the RS232/RS485 port will be turned off. In order to force ModbusLinkPlus to listen for incoming commands, tie the ‘DTR/Wake’ (terminal pin#7) to the +ve (+3.4‐13v or +8‐16v, whichever is present) terminal of the power supply. This might be useful for configuring/testing the remote units.


5. ModbusLink Network Basics

A ModbusLink network can consist of ONLY one ‘Gateway’ and one or more ‘Remote Nodes’ with the same Network‐ID. All slave units must have the same Network‐ID as the Master in order to communicate with the Master/slaves in the network. For the purpose of simplicity, the Network‐ID can be represented by an imaginary physical wire connecting each ModbusLink module to other ModbusLink modules having an identical Network‐ID, in a mesh‐like topology. Multiple networks each with their own ‘Gateway’ and ‘Remote Node(s) ‘can coexist within range of each other, provided they have unique Network‐IDS. The default Network‐ID is ‘7’. No two ‘Gateway’ modules with the same Network‐ID should be within RF range of each other.

When the Modbus Logger sends a Modbus command to the ‘Gateway’, it extracts the address information from the command and tries to find a ‘Remote Node’ with the same address in the network. If the destination node is not within radio range of the ‘Gateway’ module, it will try to discover a route via intermediate node. If multiple routes are possible to the destination, the most efficient route will be selected.

In the above figure, consider the example where the ‘Gateway’ (G) receives a Modbus command from the Modbus logger, addressed to Modbus Sensor #6.The ‘Gateway’ broadcasts a route discovery request to all ‘Remote Nodes’ in the network. Nodes#2, 3, and 5 receive the discovery request. They each note that they have a direct path to the ‘Gateway’.

Node# 3, 5 rebroadcast the discovery request. The request is received by Nodes 2, 4 and 6. Node 6 notes it has a path to the ‘Gateway’ through 2 and sends the route complete message to M through 2. Node 4 also rebroadcasts the discovery request which is also received by 6; however, it is ignored by 6 since it already has a superior route.

Once a route has been established, data can be sent through the route to the destination node. Data messages are never broadcast to conserve power. They are only addressed to a single node (unicast) which could either be the destination for the message or an intermediate node en‐route to the destination as shown below:

G

3

2

4

56

Logger


The ‘Gateway’ will send all data destined for node 6, to node 2. node 2 will in turn forward the message to node 6. The other nodes do not play any role in delivering the message to node 6, thus conserving power.

If an intermediate node cannot deliver a message to the next hop, it informs the sender, which starts a new route discovery.

Message Delivery

M

3

2

4

56


The ModbusLink Plus module is also available in a NEMA enclosure with a battery, antenna cable and an antenna.


6. Troubleshooting and Maintenance

6.1 Troubleshooting

The following checklist will help in troubleshooting problems:

PROBLEM POSSIBLE CAUSE

No/Intermittent response from (local) ModbusLink Plus module

Ensure that the module is powered and the baud rate (9600) and parity(NONE) are correctly set on the modbus master/PC side. Configure the Modbus Master/Logger to add a delay of atleast 15ms after waking the module (WAKE/DTR pin) and before sending the Modbus command.

Unable to query remote ModbusLink Plus

Ensure that the Modbus master/PC (Rs232/RS485) settings are correct.

Ensure that the remote node address matches the device ID in the modbus command

Ensure that all the modules have the same Network ID

Ensure that the Antenna is properly secured

Intermittent or lost data Ensure that the Antenna is properly secured and that LOS link is available between the node and its neighbor

Check if multiple networks have the same NW ID. Check for duplicate node addresses with the same network.

If data loss persists, change the NW ID.

Nw Scan does not report all nodes.

Check if all nodes in the network have the same NW ID. Check for duplicate Node addresses.

Analog/Digital/SDI12 sensor returns an error.

Check sensor connections.

If the sensor is powered by the switched supply, ensure that the warmup duration for that group is long enough.

6.2 Maintenance

Maintenance of the unit should be performed at regular intervals which are dependent upon the conditions of use. Typical maintenance for the unit consists of checking the wiring to make sure it is not corroded or frayed and examining the unit to ensure that there is no physical damage.


Appendix A

Writing Holding Registers Using XPert

Writing to any of the holding registers used to configure or reset certain values can be done using any MOdbus utility. Sutron’s XPert data logger offers a simple way to write Modbus registers using the Graphical setup with a ‘const’ block, an ‘MBTag’ block and an’MBut’ block as shown below. In the example below the Analog warmup is being set to 10 secs.

Edit the ‘const’ block to the new value to be written to the Holding register.

Edit the ‘MBTag’ properties and set the Base Register value to the address of holding register being written to. Also update the ‘Register Type to ‘Holding Register’ and ‘Tag Type’ to ‘ushort’.


The last step consists of setting the properties of the ‘MBOut’ block. The setting on this block are similar to the ‘MBtag’ Block.

Ensure that the COM port, Timeout and other settings are set to match the Physical com port # used. Click on the ‘values’ button and update the ‘MBOut’ Values.

Now exit the Graphical Setup tab and click the ‘Sensors’ tab. Select the MBOut block and perform a single measurement.


Appendix B

Firmware Upgrade

Serial Upgrade

The ModbusLinkPlus firmware can be upgraded using a RS232 serial connection. Once an image has been successfully uploaded to local node’s EEPROM, power cycling the node will burn the new image to flash memory.

The image can be uploaded to the local node using any terminal program (baud rate =9600, no parity) like hyperterminal or TeraTerm. To initiate the upload process power cycle the local node and press the ESC key (within 5 seconds) multiple times till the ModbusLinkPlus acknowledges each ESC keystroke with a ‘C’. The module is now ready to receive an upgrade file. Use the send file option to send the image (IHex file) to the local node. The ModbuslinkPlus will acknowledge each record with a ‘.’ .

At the end of the transfer, a status message – “Transfer successful“ or “Transfer Fail” will be displayed as shown in the screenshot below. The entire transfer usually about 5mins.

Over‐The‐Air Firmware Upgrade

Once the firmware has been successfully uploaded to the local node, it can then be disseminated to other nodes (over the air) in the Network, one node at a time. In order to send the image to a destination node address, write that node address to Holding register # 39. Once the image has been successfully sent to the remote node, it will automatically reboot itself and upgrade itself.


Appendix C

FCC and IC Certification

WARNING: The user of this product must ensure that FCC and IC labeling requirements are met. This includes a clearly visible label on the outside of the enclosure specifying the appropriate FCC/IC identifiers for this product as well as the FCC notice below.

______________________________________________________________________________________

Note: Contains FCC ID: HDB‐6461‐1311‐1

IC: 1088A‐646113111

The enclosed device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.

______________________________________________________________________________________


Appendix B

Specifications

NETWORK

Frequency 2.4 GHz license free band

Range 1mile LOS

Network type Ad‐hoc homogenous mesh

Power consumption 300µA @ 7.2v average (~3mA for ModbusLink Plus (M) if using modbus over RS485)

Battery Life ~ 3.5 years (internal battery included)

RF power 20 dBm (max)

Antenna 3.2 dBi external antenna

Leds 3 LEDs (RF, Status, Errors)

MODBUS

Modbus protocol RTU mode

Communication RS232 / RS485

Baud Rates 38400, 19200, 57600, 9600, 4800, 1200

Parity None

MECHANICAL /ENVIRONMENTAL

Enclosure 5” x 4’ x 2” NEMA rated enclosure

Weight ~400gms

Temperature ‐40C to +60C

Power Input (optional) 6‐20v

Antenna Connector RP‐SMA Female


SENSOR INPUTS

Analog 2 x single ended inputs (0‐5v) 3 x Differential inputs (0‐39mv)

Digital 1 x Frequency (Max 1Khz) 1 x Digital counter (Tipping bucket input)

SDI‐12 2 SDI sensors (max 4 parameters)

Ordering

ModbusLink

MBLinkPlus‐1 ModbusLink Plus base (does not include antenna and RP‐SMA antenna cable)

1291‐1041 3.2 dBi whip antenna

6411‐1664‐30 RP‐SMA antenna cable

MBLinkPlus‐1E ModbusLink Plus with NEMA enclosure(includes antenna, RP‐SMA antenna cable and battery )

6661‐1325‐1 3 dBi External omni antenna and mounting kit with 20 feet low loss cable.


Appendix D

Dear Customer:

Thank you for making the important decision to purchase Sutron equipment. All Sutron equipment is

manufactured and tested to the highest quality standards as set by Sutron’s Quality Assurance Department. Our

Customer Service Representatives have years of experience with equipment, systems and services. We have

electronic technicians with field and applications experience, not limited to technical school training.

Sutron Equipment Repairs

Sutron maintains a Repair Department at the Virginia factory (22400 Davis Drive, Sterling, VA 20164).

Average turn‐around time for repairs ranges from ten to thirty days after Sutron receives equipment for

repair.

Prior to returning any equipment for repair, please call Customer Service at (703) 406‐2800 for a Return

Material Authorization (RMA) number. Then send the faulty equipment back to the Virginia factory**.

Sutron Customer Service will repair Sutron‐manufactured equipment sent to us for repair within 30 days of

the time we receive the item or that repair is free of charge.*

Please provide our Customer Service Representative with your email address when receiving the RMA

number so that we can email you when your equipment is received at Sutron and again when it is shipped

back to you.

Expedited repairs can be completed within one (1) week for an additional expedite fee of $200.00.

Repaired equipment is warranted for a period of 180 days after the repair shipment date.***

We appreciate your cooperation in achieving a quick turn‐around by promptly providing cost approval

decisions, Purchase Order and credit card information once we have supplied you with a repair estimate.

Customer Phone Support: 8:00 am to 8:00 pm EST, Monday through Friday

Customer Service Representatives routinely handle a wide variety of questions every day. When equipment

questions arise, please feel free to contact me or one of Sutron’s Customer Service Representatives. We are

available from 8:00 am to 8:00 pm EST Monday through Friday and are happy to take your calls. The main

Customer Service number is (703) 406‐2800, extension #5. After 5 pm EST Monday through Friday, please use

extension #6.

We typically answer most datalogger, transmitter, sensor and interface questions on the first call. If we cannot

quickly answer a question on an interface, we will work with you until we find a solution.

Sometimes a problem is application related. Although we pride ourselves on handling 95% of application related

questions over the phone, we maintain constant contact with our Integrated Systems Division and Engineering

Division for additional assistance.


On‐Site Visits

Of course not all problems can be fixed over the phone. Sometimes a customer needs an on‐site technician to

identify site related problems or troubleshoot a network. Sutron provides these services at a reasonable cost.

Please call for details.

Training

Training is an important part of the Sutron Customer Service Success policy. With proper training, you will learn

how to take advantage of all the benefits and tools that Sutron equipment provides. We are available for, and

frequently provide, on‐site introductory training at our Customers’ facilities. We also hold three (3) day training

seminars approximately four times per year at our Sutron headquarters in Sterling (near Washington, DC).

Contact me or your Sutron Regional Sales Manager for details.

If you would like to learn more about Sutron products, please email [email protected]. Thank you again for

your business,

Paul Delisi, Customer Service Manager

[email protected]

* Note: The 30 day guarantee applies only to Sutron‐manufactured products. The 30 day guarantee does not apply to

the following: bulk shipments of 10 or more repair items, third party or buy‐ship products, shipments awaiting

payment authorizations, cases where delays are caused by international customs, shipping or other regulations.

Additionally, the 30 day guarantee is exclusive of domestic and international transit times.*

** Transportation charges for equipment returns are the responsibility of the Customer.

*** See Warranty .Any products repaired or replaced under Warranty will be warranted for the balance of the Warranty

period or for a period of 180 days from the repair shipment date, whichever is greater.


COMMERCIAL WARRANTY

SUTRON MANUFACTURED EQUIPMENT

THE SUTRON CORPORATION WARRANTS that the equipment manufactured by its Manufacturing Division shall

conform to applicable specifications and shall remain free from defects in workmanship and material for a

period ending two years from the date of shipment from Sutron’s plant.

Sutron’s obligation under this Warranty shall be limited to repair at the factory (22400 Davis Drive, Sterling, VA

20164) or, at Sutron’s option, replacement of the defective product. In no event shall Sutron be responsible for

incidental or consequential damages, whether or not foreseeable or whether or not Sutron has knowledge of

the possibility of such damages. This Warranty shall not apply to products that have been damaged through

negligence, accident, misuse or acts of nature such as floods, fires, earthquakes, lightning strikes, etc.

Sutron’s liability, whether in contract or in tort, arising out of warranties or representations, instructions or

defects from any cause, shall be limited exclusively to repair or replacement parts under the aforesaid

conditions.

Sutron requires the return of the defective electronic products or parts to the factory to establish claim under

this Warranty. The customer shall pre‐pay transportation charges to the factory. Sutron shall pay transportation

charges for the return of the repaired equipment to the customer when the validity of the damage claim has

been established. Otherwise, Sutron will pre‐pay shipment and bill the amount to the customer. All shipments

shall be accomplished by best‐way surface freight.

Sutron shall in no event assume any responsibility for repairs or alterations made other than by Sutron. Any

products repaired or replaced under this Warranty will be warranted for the balance of the Warranty period or

for a period of 180 days from the repair shipment date, whichever is greater. Products repaired at cost will be

warranted for 90 days from the date of shipment.

NON‐SUTRON MANUFACTURED EQUIPMENT

The above Warranty applies only to products manufactured by Sutron. Equipment provided, but not

manufactured by Sutron, is warranted and will be repaired to the extent of and according to the current terms

and conditions of the respective equipment manufacturers.

EXTENDED WARRANTY AND ON‐SITE MAINTENANCE

Extended warranty and on‐site maintenance contracts are available. Price quotations may be obtained from

Sutron Customer Service Representatives.

Documents

Operations Maintenance Manual - Sutron Corporation · Sutron Corporation ModbusLinkPlus Rev. C Operations & Maintenance Manual 12/15/2016 pg. 4 1. Introduction ModbusLinkPlus is an