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LabView Users Group Meeting June 20th, 2006
Process Control Using Compact Field Point/Labview Real-time
Michael TocksteinMicroelectronics Technology Department
Electronics Photonics LaboratoryJune 20th, 2006
LabView Users Group Meeting June 20th, 2006
LabView Users Group Meeting June 20th, 2006
Outline
• Furnace Bank Control Application Overview• Requirements of our System• Compact Fieldpoint (cFP) Overview• Connecting to cFP• Labview Real-Time code structure• Remote Panels• Shared Variables• Things to Remember about Real-Time Software
LabView Users Group Meeting June 20th, 2006
LabView Users Group Meeting June 20th, 2006
Our Control Project
Gas Flow
• Wafer Processing
1 2 3
LabView Users Group Meeting June 20th, 2006
LabView Users Group Meeting June 20th, 2006
Requirements• Adaptable to Existing System• Single cFP Control Unit Covers:
– Process Sequence Controller– Gas Flow Controllers– Boat Loaders– Four Three-Zone Furnace Tubes
• Programmable for new Process• Graphical User Interface• Remote Access from Office• Technician Friendly
LabView Users Group Meeting June 20th, 2006
LabView Users Group Meeting June 20th, 2006
What is Real-Time?
• Independently Run Controllers
• Real-Time = Real Reliable
LabView Users Group Meeting June 20th, 2006
Why cFP/LV Real-Time For Our System?
• Eliminates need for separate controllers for each aspect of the process (i.e. gas flow, temp control, etc…)
• Very customizable through both hardware and software
• Best interface for our “individual” channels• Very reliable since VI runs independently
from PC• Network Ready
LabView Users Group Meeting June 20th, 2006
Compact FieldPoint Assembly
• Includes:– CPU and Process Control Module– Backplane– Digital and Analog I/O Modules– Connector Blocks
LabView Users Group Meeting June 20th, 2006
LabView Users Group Meeting June 20th, 2006
cFP Backplane
• 4 or 8 channel backplanes available
• I/O modules receive power directly from backplane
• NI data bus protocol
LabView Users Group Meeting June 20th, 2006
LabView Users Group Meeting June 20th, 2006
cFP Control Module
• Labview Real-Time code runs in on-board controller, not your PC
• Ethernet port• Serial port• 11-30 VDC input. (20W power
supply recommended) • Provides power to backplane• “cFP-2000”
LabView Users Group Meeting June 20th, 2006
LabView Users Group Meeting June 20th, 2006
Discrete Output Module
• 16 Channels, 2A sinking per channel
• Used for control of gas flow
• “cFP-DO-403”
LabView Users Group Meeting June 20th, 2006
LabView Users Group Meeting June 20th, 2006
Pulse Width Modulator (PWM) Module
• 8 channels of PWM
• Used for control of Watlow 100A Solid State Relay Firing
• Pulse period parameters set through “Measurement and Automation Explorer” (MAX)
• “cFP-PWM-520”
LabView Users Group Meeting June 20th, 2006
LabView Users Group Meeting June 20th, 2006
Thermocouple Input Module
• 8 channels of any type T/C
• Used for temperature monitoring of the three zone heaters
• Selection of T/C and Cal through MAX
• Uses isothermal connector blocks
• “cFP-TC-120”
LabView Users Group Meeting June 20th, 2006
LabView Users Group Meeting June 20th, 2006
Discrete Input Module
• 32 digital input channels• Compatible with 24VDC
sourcing-output devices• Used to read important
indicators, (e.g. vacuum seal, etc…)
• “cFP-DI-304”
LabView Users Group Meeting June 20th, 2006
LabView Users Group Meeting June 20th, 2006
Connector Blocks
• Two types:– “cFP-CB-1”– “cFP-CB-3”
• Connected to corresponding module through backplane
• Used to physically wire devices to cFP unit
LabView Users Group Meeting June 20th, 2006
LabView Users Group Meeting June 20th, 2006
cFP Hardware Setup
• NI Measurement and Automation Explorer– Will “see” any NI hardware on the network– Assign IP address– Set parameters– Ready to Go!
LabView Users Group Meeting June 20th, 2006
Components of the Real-Time Software
• “Drivers” for each cFP module• PID control blocks
– Needed to control temperature
• Program “step” code– Needed to take program through the logical sequence
of events required for a specific process
• Safety shutdown code– Temperature Overshoot– Zone Differential Exceeded– Manual Shutdown
LabView Users Group Meeting June 20th, 2006
LabView Users Group Meeting June 20th, 2006
cFP Module “Drivers” in LV 7.1
LabView Users Group Meeting June 20th, 2006
LabView Users Group Meeting June 20th, 2006
“Drivers” in Labview 8
• “Drivers” are much easier to implement in Labview 8.
• Labview 8 has “drag and drop” features which allow you to drag a specific channel of a device (along with it’s “drivers”) over to your VI from the project window.
LabView Users Group Meeting June 20th, 2006
Drag and Drop “Drivers” For Each Device Channel
Source: [1]
LabView Users Group Meeting June 20th, 2006
What is PID?
• Proportional-Integral-Derivative
PIDCompensator
SYSTEM+-
Desired Setpoint
LabView Users Group Meeting June 20th, 2006
PID Control Blocks
• Necessary for each zone of our temperature controller
LabView Users Group Meeting June 20th, 2006
LabView Users Group Meeting June 20th, 2006
High Level Program Flow Chart
User EntersTable Values
Start Program
Read InputsFrom cFP
Compare InputsTo Table
Activate DesiredOutputs
Set Center ZoneTemperature
Set DelayCounter
Compare DelayCounter to Zero
Increment RowCounter
Reset ColumnCounter
IncrementColumn Counter
IncrementColumn Counter
IncrementColumn Counter
Outer ZonesTrack Center
Zone Temperature
True
False
False
True
LabView Users Group Meeting June 20th, 2006
Program Step Code
• Reads Table
• Determines if input requirements are met
• Activates desired outputs
• Sets new temp
• Waits a desired time before next step
LabView Users Group Meeting June 20th, 2006
Program Table
LabView Users Group Meeting June 20th, 2006
LabView Users Group Meeting June 20th, 2006
Program Table Values• Decimal numbers correspond to a binary value which
represents I/O ports.• Example for a particular output step:
Actual = N2 NH3 H2SiCl2 GateValve A B C D Want = On OFF OFF On On Off On OnBinary = 1 0 0 1 1 0 1 1
10011011b = 155dTech enters 155 into table.• Independent number conversion needed to save memory
space onboard real-time controller. LabView Users Group Meeting June 20th, 2006
LabView Users Group Meeting June 20th, 2006
Control Panel
• Available on host PC and remote window.
LabView Users Group Meeting June 20th, 2006
LabView Users Group Meeting June 20th, 2006
Remote Panel
• Built in Web server.
• Monitor/control your application from a Web browser
• Advantage to user running a long duration process
LabView Users Group Meeting June 20th, 2006
Shared Variables
• Allows easy communication of data between Real-Time target VI and Host VI
• Save program memory onboard Real-Time target by conducting most processing tasks on board PC using Host VI
• Available only in Labview 8
LabView Users Group Meeting June 20th, 2006
Things To Remember About The Real-Time Software
• When you execute your program, it is downloaded and run on the Real-Time controller, not your PC!– This effects the size of your program and
ultimately limits the number of “bells and whistles” you can have
LabView Users Group Meeting June 20th, 2006
Summary
• Advantages of using cFP w/ LV Real-Time:– Very Flexible– Expandable– Relatively Easy to Understand– Simple Network Interface
• Disadvantages:– Limited Memory– Expensive
LabView Users Group Meeting June 20th, 2006
LabView Users Group Meeting June 20th, 2006
References[1] NI LabView Real-Time Hands-On Seminar Manual.
February 2006 Edition. Part Number 351171C-01
Additional ResourcesI. National Instruments: www.ni.com
II. Compact Field Point: http://www.ni.com/compactfieldpoint/
III. Labview Tour: http://www.ni.com/swf/labview/us/tour