Tutorial 3: pid control of a simulated process, Tutorial 3: pid control of a simulated process -5 – National Instruments NI-FBUS User Manual
Page 63
Chapter 3
NI-FBUS Configurator Tutorials
© National Instruments Corporation
3-5
NI-FBUS Configurator User Manual
You also can monitor the configuration using the block configuration
window for any individual function block. Observe the values and
changes in the parameters. Check the Periodic Updates box to cause
the parameters to be read at the specified rate when the block is
running.
Tutorial 3: PID Control of a Simulated Process
This tutorial assumes you have already gone through Tutorial 2, which
describes how to modify function blocks, write parameters, and test a
configuration.
1.
If necessary (that is, if your device supports function block
instantiation), create a PID function block.
a.
Right-click the device in the configuration tree and select
Instantiate New Block.
b.
Select PID Block and click OK.
c.
Right-click the new tag and select Set Tag. Change the name of
the tag to something like
FP-PID
.
2.
Open the Function Block Application Editor window.
3.
Create a PID Feedback control application using the control templates
that come with the NI-FBUS Configurator.
a.
Right-click in an empty area of the Function Block Application
Editor window.
b.
Select FBAP Templates»PID Feedback Control. A dialog box
asks if you want to use the parameters saved in the template. Since
this is a generic template, the function block parameters are
probably more suitable than the template parameters. Choose No.
This operation places a PID template on the Function Block
Application Editor window. Notice the blocks are grayed
out—a visual indication that the blocks are merely shells.
4.
Assign function blocks to fill in the template blocks.
a.
Right-click an AI template block, highlight Replace With,
and select an AI function block. This block will provide the
process value to the PID block.
b.
Right-click the AO template block, highlight Replace With,
and select an AO function block. This block is the output that will
be controlled by the PID block.
c.
Right-click the PID template block, highlight Replace With,
and select a PID function block.