Process Controller Pid1 - ABB ACS355 series User Manual

152 Program features


Process controller PID1

PID1 has two separate sets of parameters
PID SET 2). Selection between parameter sets 1 and 2 is defined by a parameter.
In most cases when there is only one transducer signal wired to the drive, only
parameter set 1 is needed. Two different parameter sets (1 and 2) are used, eg, when
the load of the motor changes considerably in time.

External/Trim controller PID2
PID2 (42 EXT / TRIM
• External controller: Instead of using additional PID controller hardware, the user
can connect PID2 output through drive analog output or fieldbus controller to
control a field instrument like a damper or a valve.
• Trim controller: PID2 can be used to trim or fine tune the reference of the drive.
See section Reference trimming

Block diagrams
The figure below shows an application example: The controller adjusts the speed of a
pressure boost pump according to the measured pressure and the set pressure
reference.
Example:
Pressure boost pump
A C S 6 0 0
Drive
A C T P A R F U N C D R I V E
E N T E R
L O C R E S E T R E F
R E M
3
0 . . . 1 0 b a r
2
4 . . . 2 0 m A
3
PID) can be used in two different ways:
on page 130.
PID control block diagram
%ref
Actual values
4014
.
. .
4021
AI1
AI2
IMOT
(40 PROCESS PID SET
PID
ref
4001 k
ti
4002
td
4003
i
4004 dFiltT
errVInv
4005
PIDmax
oh1
ol1
PIDmin
...
%ref = 4010
1, 41 PROCESS
Switch
Frequency
reference
Speed
reference
9904 = 0