Micromod Micro-DCI: 53MC5000 Multi-Loop Process Controller Instruction Manual - Manual (Page 262)

14.0 CS40 - DUAL TWO LOOP CASCADE
CONTROLLER
14.1 CS40 - DUAL TWO LOOP CASCADE CONTROLLER
The Dual Two Loop Cascade Controller provides four standard PID controllers that function as two
cascade pairs. Each cascade pair is arranged with a primary and related secondary controller.
Transfer between local and cascade control in each cascade pair is bumpless and balanceless be-
cause each pair’s primary controller output is forced to match the secondary controller setpoint
when the secondary controller is in local mode. (See Section 12, Two Loop Cascade Controller for
process application description.) A typical low-resolution display Dual Two Loop Cascade Control-
ler application is illustrated in Figure 14-1.
Ensure the controller is capable of supporting four control loops by comparing the model number of
the controller (found on the controller tag) with the model number breakdown provided in Section 1.
Figure 14-1. Typical CS40 Dual Two Loop Cascade Controller
Application
B
C
A 1 A
2
A 1 , B, C = #1 PRIMARY LOOP
A 2 , B, C = #1 SECONDARY LOOP
D 1
D 2
E
F
D 1 , E, F = #2 PRIMARY LOOP
D 2 , E, F = #2 SECONDARY LOOP
TT
VALVE
COLD
WATER
AI1 - #2 PRIMARY
PROCESS VARIABLE
AI3 - #2 SECONDARY
PROCESS VARIABLE
DI1 - #2 CASCADE ENABLE
(CLOSED CONTACT)
DI0 - #1 CASCADE ENABLE
(CLOSED CONTACT)
AI2 - #1 SECONDARY PROCESS VARIABLE
AI0 - #1 PRIMARY
PROCESS VARIABLE
AO1 #2 SECONDARY
CONTROL OUTPUT
DO1 - #2 SECONDARY PROCESS
ALARMS
DO0 - #1 SECONDARY PROCESS
ALARMS
AO0 - #1 SECONDARY
CONTROL OUTPUT
PUMP
TT
TT TT
PUMP
VALVE
STEAM
Section 14. CS40 - Dual Two Loop Cascade Controller
14-1