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36 control 3 – Micromod Micro-DCI: 53MC5000 Multi-Loop Process Controller FLEXIBLE CONTROL STRATEGIES User Manual

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2.7.36 CONTROL 3

The Control 3 (CON 3) module combines the operations of Deviation/Alarm Calculation (D/C) and
Proportional Integral Derivative (PID) modules. The D/C functionality of the CON 3 module calcu-
lates the deviation (DV) value from the setpoint (SP) and the process variable (PV). Before the cal-
culation is performed, the setpoint value is conditioned not to exceed the T1 rate of change limit. If
the calculated deviation falls within the Control Zone (CZ) value, the deviation is forced to 0.0. If
the DV value exceeds parameter values that were entered for alarm limits PL1 and PL2, and the
Alarm Deadband (ADB), then Process Alarms PA1 and PA2 are activated as determined by the
Control Alarm Mode (AIX) parameter selection. The DV output from the D/C functionality is routed
internally as the DV input to the PID functionality, which means it can not be accessed as a wirelist
datapoint as would be the case if both modules were separate. The PID functionality computes the
Control Output (CO) signal based on the DV input from the D/C, other input variables, and parame-
ter entries (see Section 2.7.15 or 2.7.26 for PID formulas).

When the Auto/Manual Switch 3 (AMS 3) module is in auto mode, the CON 3 CO output is forced
to equal the Auto Value (CO) out from the AMS 3 module.

The tables that follow list the input variables and the parameters. An illustration of the Control 3
module follows the tables.

Inputs

WIRELIST

SYMBOL

DATA

TYPE

ASSIGNED VALUE

B230

PV3

C

B231

SP3

C

B232

FF3

C

Output Datapoints: C227, C229, C231, L182, L183

Parameters

Parameters

SYMBOL

DATAPOINT

ASSIGNED VALUE

SYMBOL

DATAPOINT

ASSIGNED VALUE

T1-3

C225

OL3

C218

CZ3

C222

IR3

C223

PL1-3

C211

PB3

C214

PL2-3

C212

TR3

C215

ADB3

C213

TD3

C216

AIX3

B350

MR3

C219

OH3

C217

RSW3

L178

Section 2. FCS Modules

CON-3

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