Rockwell Automation 1746-BTM Barrel Temperature Control Module User Manual - Manual (Page 41)

1 Publication 1746-UM010B-EN-P - April 2001
Chapter
4
Setting Autotune and Gains Values
This chapter shows you how to independently set the gains for each
PID loop of the BTM module. This includes:
•
setting PID gains
•
autotuning the loops
•
fine tuning the loops
•
using the PID equation
•
configuring the autotuning and gains block
Sequence of Setting PID
Gains Any time you successfully autotune the loop, write an autotune block
to the module, or write a gains block to the module, a new set of PID
gains is established on the module. The following list summarizes the
process:
•
Autotuning causes the module to measure the process dynamics
and calculates PID gains.
•
Reading the PID gains block from the module copies the PID
gains generated by autotuning into the SLC files.
•
Writing the PID gains block to the module overwrites any PID
gains that had been in the module.
•
Autotuning or writing the autotune block to the module causes
the module to calculate PID gains and overwrite any PID gains
that had been in the module.
At initial start–up, you must write the autotune block to the BTM
module or perform autotuning. If you select autotuning, for any loop
that is successfully tuned, the gains are calculated by the module.
Gains you sent to the module for a loop in any gains block previous
to successful autotuning of the loop are superseded by the gains
derived from autotuning. If you then read the gains block, it contains
the gains derived from autotuning.
If autotuning is not successful for any loops (as indicated in the status
block) the gains you sent for those loops before autotuning is used by
the module.