Steps to Create a PID Control Loop with the FP-3000 Network Module

Primary Software: Driver Software>>NI-FBUS
Primary Software Version: 2.3.5
Primary Software Fixed Version: N/A
Secondary Software: N/A

Problem: I would like to create a PID control loop with my FP-3000 Network Module, but the manuals don't explain this very well. What do I need to do in order to create a PID control loop with the FP-3000?

Solution: The following steps should help get you started with your PID control loop. This explanation uses a hypothetical setup, where an FP-AO-200 Current Output Module and an FP-AI-110 Analog Input Module are connected to the FP-3000 Network Module. In this example, we are going to set the Analog Input module to read 0 to 5.2V and the Analog Output module to produce 0 to 21 mA. It is recommended that you follow this guide exactly the first time through. Once you get one PID loop running, then make adjustments to match your needs.

Note 1: You will need to connect a current load (or field device) to channel 0 of the FP-AO-200. Generally, this will involve connecting the load to pin 1 (Current Out) and pin 2 (Common). You will also need to provide power for the analog output circuitry of the analog output module. This involves connecting a power supply to one pair of the V and C terminals on the terminal base. This can be done in several ways. See KnowledgeBase 1RL9K2US for more information on powering output modules and the implications for isolation. If the device is a loop-powered device, pin 17 (V Supply) can be used to power the device. See the FP-AO-200 Operating Instructions for more information on field wiring.

Note 2: This document also assumes that you have connected the FP-3000 to the bus, successfully launched the NI-FBUS Configurator version 2.3 or later, and done nothing more.

Note 3: If you are using NI-FBUS Configurator version 2.3.5 or later, the Autoconfigure function will run automatically the first time the FP-3000 is connected to the bus. You can skip step 3.

1. In the left-hand side of the Configurator window you will see a heading for your FP-3000 (e.g., Fieldpoint-4E49434005_FP3000_00B). Under this heading will be an entry that says:

----- NO TAG ----- (RB)

Right-click on this entry and select Set Tag from the pop-up menu. Enter "my3000" (or another suitable name) as the new name.

2. Right-click on the newly renamed "my3000" tag and select Open from the pop-up menu. This will open a new window. Make sure that the OOS button is depressed.

3. Go to the Options tab and change the value of the FP_Autoconfigure parameter to "Autoconfigure", and then press the Write Changes button. Wait until all modules are autodetected (this may take some time).

4. Close the new window and then right-click on the heading for your FP-3000.

5. Select Instantiate New Block from the pop-up menu. Set the Block Type to "Pid Block" and set the number of blocks to 1. This will create a new entry under the heading for your FP-3000 called:

----- NO TAG -----(PDIC)

Right-click on this entry and select Set Tag from the pop-up menu. Enter "myPID" (or another suitable name) as the new name.

6. In the left-hand side of the Configurator window is a heading called Function Block Application. Double-click on this heading. This will open a white panel called the Function Block Application Editor in the middle of the Configurator window. This is the area where you will graphically connect your function blocks.

7. Right-click in the center of Function Block Application Editor and select FBAP Templates >> PID Feedback Control from the pop-up menu. This will bring up a window that asks if you want to use the currently saved values. Click the No button. You should now see three function block template entries in the Function Block Application Editor: Template (AI), Template (PID), and Template (AO).

8. Right-click on Template (AI) and select Replace With >> Fieldpoint-4e49434005_FP3000_00B0 >> FPModule 02 Channel 00 (AI110) from the pop-up menu. (Your choices in this menu will look slightly different. The module number will depend on where your module is physically located in the bank.)

9. Right-click on Template (PID) and select Replace With >> Fieldpoint-4e49434005_FP3000_00B0 >> myPID (PIDC) from the pop-up menu.

10. Right-click on Template (AO) and select Replace With >> Fieldpoint-4e49434005_FP3000_00B0 >> FPModule 01 Channel 00 (AO200) from the pop-up menu.

11. Double-click on the AI function block to open its properties window and ensure the following parameters are set as below:

I/O Config Tab
   FP_AI_110_RANGE   0-5.2V

Assuming you have not changed some of the FP-3000 optional settings, changing this parameter will appropriately adjust the XD_SCALE below:

Scaling Tab
   OUT_SCALE
      EU_100             100
      EU_0                 0
      UNITS_INDEX          %
	
   XD_SCALE
      EU_100             5.2
      EU_0                 0
      UNITS_INDEX          V (capital V for volts)
      L_TYPE        Indirect

Click on the Write Changes button and then close the window.

11. Double-click on the AO function block to open its properties window and ensure the following parameters are set correctly:

I/O Config Tab
   FP_AO_200_RANGE   0-21 mA

Assuming you have not changed some of the FP-3000 optional settings, changing this parameter will appropriately adjust the XD_SCALE below:

Scaling Tab
   PV_SCALE
      EU_100        100
      EU_0            0
      UNITS_INDEX     %
	
   XD_SCALE
      EU_100          0.021
      EU_0            0
      UNITS_INDEX     A (capital A for amps)

Click on the Write Changes button and then close the window.

12. Double-click on the PID function block to open its properties window and ensure the following parameters are set correctly:

Process Tab
   SP
      VALUE     50
      (the range is 0-100, arbitrary set-point)
	
Scaling Tab
   PV_SCALE
      EU_100        100
      EU_0            0
      UNITS_INDEX     %
	
   OUT_SCALE
      EU_100        100
      EU_0            0
      UNITS_INDEX     %
	
Tuning Tab
   GAIN       1.5
   RESET     10 Sec
   RATE       0 Sec

(Note: The GAIN, RESET, and RATE will be unique for your system.) Click on the Write Changes button and then close the window.

13. Click on the Download Project icon in the taskbar. This will open the Download Configuration window. Select the Write Contained Block Parameters, the Clear Devices, and the Automatic Mode Handling options. Then click the Download button.

14. When the download process finishes (you will see a pop-up message that confirms this), click the Done button to close the Download Configuration window.

15. Your blocks should all be in Auto mode. Click the Monitor Mode icon (it looks like an eye) to observe the behavior of your PID loop. You can adjust the monitoring rate down from 5 seconds so that it reads the values more frequently.

Related Links: Product Manuals: NI-FBUS Configurator User Manual
Product Manuals: FP-3000 Network Module User Manual
Product Manuals: FieldPoint FP-3000 Network Module Operating Instructions

Attachments:

Report Date: 02/22/2000
Last Updated: 04/05/2005
Document ID: 1ULD4SM6

Your Feedback!

Poor | Excellent

Yes

Document Quality?

Answered Your Question?

Please Contact NI for all product and support inquiries.