100 Program features
In process PID control, a process reference (setpoint) is connected to the drive
instead of a speed reference. An actual value (process feedback) is also brought
back to the drive. The process PID control adjusts the drive speed in order to keep
the measured process quantity (actual value) at the desired level (setpoint). This
means that user does not need to set a frequency/speed/torque reference to the drive
but the drive adjust its operation according to the process PID.
The simplified block diagram below illustrates the process PID control. For more
detailed block diagrams, see pages 452 and 453.
The drive contains two complete sets of process PID controller settings that can be
alternated whenever necessary; see parameter 40.57 PID set1/set2 selection.
Note: Process PID control is only available in external control location EXT2; see
section Local control vs. external control (page 85).
Process
PID
AI1
Process
actual
values
AI2
• • •
FBA
Setpoint
Speed, torque or
frequency
reference chain
Filter
Limitation
ACS580 FW.book Page 100 Wednesday, September 21, 2016 9:48 PM
To Next Page
Loading...
