RKC INSTRUMENT Z-TIO-G, Instruction Manual

Page: 192 / 246

9. COMMUNICATION DATA DESCRIPTION
IMS01T28-E4
9-84
 Cascade control function
Cascade control monitors the controlled object temperature in the master unit and then corrects the set
value in the slave unit depending on the deviation between the target value (set value) and actual
temperature. The slave unit controls the non-controlled object (heater, refrigeration device, etc). As a result,
the controlled object temperature can be reached and controlled at the target value.
At cascade control that uses internal communication, one of the channels of the connected modules is
specified the master, and the other arbitrary channels of the modules are controlled as slaves.
Example: When two Z-TIO modules are used for Cascade control
Address 0 (CH1) is set as the master channel and the Address 1 channels (CH1, CH2) are used as slaves.
If “1: Cascade control function” is selected with the SV select function, the Manipulated output (MV) of
the master will be the Set value (SV) of the slave.
Master cannel
(CH1)
Communication
PV
Slave cannel
(CH2)
Slave cannel
(CH3)
Heater Heater
Cylinder
Nozzle
(Extruder)
Sensor
Sensor
Sensor
Communication
PV
Master MV
Local SV
PID
MV
Digital
filter
Master
Bias
Remote SV
Scale
conversion
MV
Local SV
PID
Remote SV
(Internal communication)
Z-TIO module
Communication
PV
Master MV
Local SV
PID
MV
Digital
filter
Master
Bias
Remote SV
Scale
conversion
Block diagram of Cascade control by internal communication