ABB ACS280, Firmware Manual, Page: 61 / 430

Program features 61
reference source is AI scaled, then
22.11 Ext1 speed ref1
and
40.53 Set 1 trimmed
ref pointer should be configured to AI1 scaled .
Parameter
40.05 Process PID trim output act
is calculated using the following
formula:
The below graph shows the PID trim output in proportional mode throughout
the speed range. Here, the trimmed output is directly proportional to the value
of parameter 40.53 Set 1 trimmed ref pointer .
Note: In the above graph, it is assumed that the PID output is limited or stable
at 100. This is for understanding purpose only. In real case scenario, PID output
can vary based on the setpoint and actual.
Example :
If:
parameter
40.52 Set 1 trim selection
=
Speed
parameter
40.56 Set 1 trim source
=
PID output
parameter
40.53 Set 1 trimmed ref pointer
=
AI1 scaled
parameter
22.11 Ext1 speed ref1
=
AI1 scaled
parameter
12.20 AI1 scaled at AI1 max
= 1500
parameter
12.12 AI1 scaled value
= 750 (AI1 actual scaled value)
parameter
40.01 Process PID output actual
= 100 (limited to 100)
parameter
40.55 Set 1 trim adjust
= 0.5,
then:
Par40.05
Par40.01
100
------------------------
 
 
Par40.53  Par40.55 
=
40.55 Set 1 trim adjust
40.53 Set 1 trimmed ref pointer
0
40.05 Process PID trim output act
Par40.05
100
100
----------
 
 
750  0.5 
=
Par40.05 375
=