ABB ACS280, Firmware Manual, Page: 62 / 430

62 Program features
At zero speed, the
40.05 Process PID trim output act
value depends on both the
40.55 Set 1 trim adjust and 40.54 Set 1 trim mix parameter values. However,
adjusting
40.54 Set 1 trim mix
near to zero speed will give quick correction.
Example :
If,
parameter 40.52 Set 1 trim selection = Speed
parameter
40.56 Set 1 trim source
=
PID output
parameter 30.12 Maximum speed = 1500 rpm
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 40.54 Set 1 trim mix = 0.1
parameter
40.55 Set 1 trim adjust
=
0.5
then
Combined
The combined mode is suitable for applications where the user needs to
maintain tension from zero speed to maximum speed. The combined mode is a
combination of direct and proportional modes. Here, the trim for zero speed is
defined by parameter
40.54 Set 1 trim mix
and the trim for speed greater than
zero speed is defined by parameter 40.55 Set 1 trim adjust . The trim value is
directly proportional to the value of parameter
40.53 Set 1 trimmed ref pointer
.
The process speed reference is connected in parameter 40.53 Set 1 trimmed ref
pointer
. For example, if EXT1 control mode is used and the reference source is
AI1 scaled , then 22.11 Ext1 speed ref1 and 40.53 Set 1 trimmed ref pointer shall
be configured to
AI1 scaled
.
The 40.05 Process PID trim output act is calculated using the following formula:
Par40.05
100
100
----------
 
 
750  0.5 
=
Par40.05 375
=