Cascade Control Function - Mitsubishi Electric MELSEC-Q Series User Manual

3 SPECIFICATIONS

3.2.13 Cascade control function

Master
(CH1)
Slave
(CH2)
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(1) Cascade control function
The cascade control can perform the control with the channel 1 as master and
the channel 2 as slave. The channel 2 cannot be used as master and the
channel 1 cannot be used as slave.
The master performs PID operations by inputting the measured value (PV1) of
targets that are controlled at the last, converts the manipulated value (MV1) to
cascade signals by bias and gain, and corrects the set value (SV2) of the slave.
The slave performs the PID control according to the set value (SV2) corrected
into the cascade signals.
-
PV1
+
SV1
-
PV2
+
SV2
+
The cascade control is suitable for when there is a large time delay between the
heater and the part where needs temperature stabilized.
Example) Resin temperature control of a nozzle part of an extrusion machine
PID operation
PID operation
Gain
Cascade
signals
MELSEC-Q
MV1
Cascade
ON
MV2
Bias
Cascade
OFF
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