ABB ACS280, Firmware Manual, Page: 59 / 430

Program features 59
The examples provided in this chapter are based on PID set 1. You can set the
desired values for the PID trim function parameters to get the expected result.
When PID trim is activated, bit 5 Trim mode is set to 1 in parameter
40.06
Process PID status word .
See the speed, torque and frequency reference chains in chapter
10 Control
chain diagrams for more information on the PID trim addition to the respective
reference chains.
The following PID trim modes are available:
• Direct
• Proportional
• Combined
Direct
The direct method is suitable when you need tension control at fixed rpm/line
speed.
In this mode, the PID trim output (parameter
40.05 Process PID trim output act
)
is relative to the maximum speed (parameter 30.12 Maximum speed ), torque
(
30.20 Maximum torque 1
) or frequency (
30.14 Maximum frequency
). You can
make the selection with parameter 40.52 Set 1 trim selection .
The calculated trimmed output actual is the same throughout the speed range
with respect to the stable PID output.
The
40.05 Process PID trim output act
value is calculated using the following
formula:
Par40.05
Par40.01
100
------------------------
 
 
Par30.12 or 30.20 or 30.14    Par40.55 
=