ABB ACS180 Firmware Manual page 75

The graph below shows the PID trim output in direct mode throughout the speed
range. A fixed trim speed reference is added throughout the speed range.
40.05 Process PID trim output act
0
Note: In the above graph, it is assumed that the PID output is limited or stable at 100.
This is for clarity only. In real life scenarios, the PID output can vary based on the
setpoint and the actual value.
Example:
If:
parameter 40.52 Set 1 trim selection
parameter 40.56 Set 1 trim source
parameter 30.12 Maximum speed
parameter 40.01 Process PID output
parameter 40.55 Set 1 trim adjust
then:
100
 
--------- -
Par40.05 =
 
100
Par40.05 = 750
Proportional
The proportional method is suitable for applications where tension control is required
throughout the speed range but not near zero speed.
In this mode, the PID trim output actual (parameter
) is relative to the reference selected by parameter
and with 40.01 Process PID output actual
It is recommended that the speed reference selected in
pointer and the reference source in
to make the proportional mode active.
In most of the use cases, the process speed reference is connected in
trimmed ref pointer. For example, if EXT1 control mode is used and the reference
Drive speed reference
= Speed
= PID output
= 1500 rpm
actual= 100 (limited to 100)
= 0.5,
 
1500 0.5
22.11 Ext1 speed
40.55 Set 1 trim adjust
40.05 Process PID trim output act
40.53 Set 1 trimmed ref pointer
or 40.03 Process PID setpoint
40.53 Set 1 trimmed ref
ref1are equal. This is required
Program features 75
actual.
40.53 Set 1