Cascade Standard Control; Cascade Heating/Cooling Control - Omron E5AR-T User Manual

■ Cascade Standard Control

● AT with Cascade
Control
IN1
PV
+
SP
PID
MV
Channel 1
Remote SP
RSP
SP
FSP
Fixed SP
Channel 2
OUT1
● Operation for
Primary Side Input
Errors

■ Cascade Heating/Cooling Control

The Control Mode parameter does not need to be set for Position-proportional Control Models. These
models always perform position-proportional control.
• Cascade control can be performed using standard control (heating
control or cooling control).
• Input 1 is for the primary loop (channel 1) and input 2 is for the
secondary loop (channel 2).
(1) Execute AT for the secondary side to find the suitable PID
constants.
Set the PV on the secondary side during stable control near the
IN2
primary side SP as the fixed SP for the secondary side.
Set the channel 2 SP mode to Fixed SP Mode (cascade open), set
the secondary side to independent control and execute AT.
Once AT has been completed, find the secondary side PID
constants.
(2) Change to cascade control and execute AT for the primary side to
find the suitable PID constants.
PV
+
Change the channel 2 SP mode to Remote SP Mode (cascade
closed), change to cascade control, and execute AT for channel 1.
PID
MV
If an error occurs on the primary side, the value set for the MV at PV
Error parameter is output as the primary side (channel 1) MV. The
secondary side continues control of the remote SP equivalent to the
primary side setting for the MV at PV Error parameter. This means that
the primary side (channel 1) MV at PV Error parameter must always
be set.
• Cascade control can be performed using heating/cooling control.
• Input 1 is for the primary loop (channel 1) and input 2 is for the
secondary loop (channel 2).
4.6 Selecting the Control Mode
4-17