Siemens SIMATIC S7-1500T Function Manual

Using PID_Temp
6.4 Cascade control with PID_Temp
PID control
Function Manual, 03/2017, A5E35300227-AC
195
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
DB parameter
Explanation
Basic settings → Cascade:
Activate "Controller is master" check
box
Config.Cascade.IsMaster =
TRUE
Activates this controller as a master in a cas-
cade
Basic settings → Cascade:
Number of slaves
Config.Cascade.CountSlaves Number of directly subordinate slaves that
receive their setpoint directly from this master
Basic settings → Input/output parame-
ters:
Selection of the output value (heating)
= OutputHeat
Config.Output.Heat.Select = 0 The master only uses the output parameter
OutputHeat.
OutputHeat_PWM and OutputHeat_PER are
deactivated.
Basic settings → Input/output parame-
ters:
Clear "Activate cooling" check box
Config.ActivateCooling =
FALSE
The cooling has to be deactivated at a master.

Siemens SIMATIC S7-1500T Specifications

General

Brand	Siemens
Model	SIMATIC S7-1500T
Category	Controller
Language	English