ABB ACS850 series, Manual

Page: 94 / 370

94 Application macros
PID control macro
The PID control macro is suitable for process control applications, for example
closed-loop pressure, level or flow control systems such as
• pressure boost pumps of municipal water supply systems
• level-controlling pumps of water reservoirs
• pressure boost pumps of district heating systems
• material flow control on a conveyor line.
The process reference signal is connected to analog input AI1 and the process
feedback signal to AI2. Alternatively, a direct speed reference can be given to the
drive through AI1. Then the PID controller is bypassed and the drive no longer
controls the process variable.
Selection between direct speed control (control location EXT1) and process variable
control (EXT2) is done through digital input DI3.
The stop/start signals for EXT1 and EXT2 are connected to DI1 and DI6 respectively.
A constant speed (300 rpm) can be activated through DI4.
Default parameter settings for PID control macro
Below is a listing of default parameter values that differ from those listed in chapter
Additional parameter data (page 263 ).
Parameter
PID control macro
default
No. Name
10.04 Ext2 start func In1
10.05 Ext2 start in1 DI6
10.10 Fault reset sel C.FALSE
12.01 Ext1/Ext2 sel DI3
13.05 AI1 min scale 0.000
13.09 AI2 max scale 1500.000
13.10 AI2 min scale 0.000
21.02 Speed ref2 sel PID out
21.04 Speed ref1/2 sel DI3
26.02 Const speed sel1 DI4
26.06 Const speed1 300 rpm