Configuration - Siemens SIMATIC S7-1200 Function Manual

6.4.3

Configuration

You can carry out the configuration via your user program, the configuration editor or the
Inspector window of the PID_Temp call.
When using PID_Temp in a cascade control system, ensure the correct configuration of the
settings specified below.
If a PID_Temp instance receives its setpoint from a superior master controller and outputs its
output value in turn to a subordinate slave controller, this PID_Temp instance is both a
master controller and a slave controller simultaneously. Both configurations listed below
have to be carried out for such a PID_Temp instance. This is the case, for example, for the
middle PID_Temp instance in a cascade control system with three concatenated measured
variables and three PID_Temp instances.
Configuration of a master
Setting in the configuration editor or
Inspector window
Basic settings → Cascade:
Activate "Controller is master" check
box
Basic settings → Cascade:
Number of slaves
Basic settings → Input/output parame-
ters:
Selection of the output value (heating)
= OutputHeat
Basic settings → Input/output parame-
ters:
Clear "Activate cooling" check box
PID control
Function Manual, 03/2017, A5E35300227-AC
DB parameter
Config.Cascade.IsMaster =
TRUE
Config.Cascade.CountSlaves
Config.Output.Heat.Select = 0
Config.ActivateCooling =
FALSE
6.4 Cascade control with PID_Temp
Explanation
Activates this controller as a master in a cas-
cade
Number of directly subordinate slaves that
receive their setpoint directly from this master
The master only uses the output parameter
OutputHeat.
OutputHeat_PWM and OutputHeat_PER are
deactivated.
The cooling has to be deactivated at a master.
Using PID_Temp
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