Siemens SIMATIC 505 - Initial Loop-Tuning Parameter Values; Before Tuning Loops

Selected Functions
5-23
5.11.3
Check the following items before tuning loops:
• Clamp and ram position inputs must be steady (not more than
± 16 counts). If the counts exceed this range, the loop cannot be tuned
correctly.
• Adjust zero and span of the valve amplifier cards.
• Have on hand a strip chart recorder (2 channels or more). T able 5-2 lists
approximate initial values of the parameters to set up the loop.
T able 5-2 Initial Loop-tuning Parameter V alues
Parameters Standard Dynamic
Velocity scaling factor (VSF) 16–24 16–24
Loop Gain (P) 500 500
Loop Rate (R) None None
Loop Reset (I) 20000 0
Rate is rarely needed for T urboPlastic applications since the
process response is quick.
Reset is always needed in the standard algorithm since gain by
itself produces a constant output.
Before T uning
Loops
CAUTION
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