Pid code sample – Rockwell Automation 2080-LC10-12DWD Micro810 Programmable Controllers User Manual User Manual
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Rockwell Automation Publication 2080-UM001D-EN-E - September 2012
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IPID Function Block Appendix D
energy for the former and the inductive and capacitive storage energy for the
latter. Motor drive systems and heating systems can be typically modeled by the
LR and C electric circuit.
PID Code Sample
The illustration above shows sample code for controlling the PID application
example shown before. Developed using Function Block Diagrams, it consists of
a pre-defined function block, IPIDCONTROLLER, and four user-defined
function blocks. These four are:
• PID_OutputRegulator
This user-defined function block regulates the output of
IPIDCONTROLLER within a safe range to ensure that there is no
damage to the hardware used in the process.
IF RMIN
≤ RIN ≤ RMAX, then ROUT = RIN,
IF RIN < RMIN, then ROUT = RMIN,
IF RIN > RMAX, then ROUT = RMAX.
• PID_Feedback
This user defined function block acts as a multiplexer.
IF "FB_RST" is false, FB_OUT=FB_IN;
If "FB_RST" is true, then FB_OUT=FB_PREVAL.