Output Settings; Basic Settings Of Output - Siemens SIMATIC S7-1200 Function Manual

Using PID_Temp
6.2 Configuring PID_Temp
6.2.3

Output settings

6.2.3.1

Basic settings of output

Method for heating and cooling
If cooling is activated in the basic settings, two methods are available for calculating the PID
output value:
● PID parameter switching (Config.AdvancedCooling = TRUE):
The output value calculation for cooling takes place by means of a separate PID
parameter set. Based on the calculated output value and the control deviation, the PID
algorithm decides whether the PID parameter for heating or cooling is used. This method
is suitable if the heating and cooling actuators have different time responses and different
gains.
Pretuning and fine tuning for cooling are only available if this method is selected.
● Cooling factor (Config.AdvancedCooling = FALSE):
Output value calculation for cooling is effected with the PID parameters for heating under
consideration of the configurable cooling factor Config.CoolFactor. This method is
suitable if the heating and cooling actuators have a similar time response but different
gains. If this method is selected, pretuning and fine tuning for cooling as well as the PID
parameter set for cooling are not available. You can only execute the tuning for heating.
Cooling factor
If the cooling factor is selected as the method for heating/cooling, this factor is used in the
calculation of the output value for cooling. This allows different gains of heating and cooling
actuators to be taken into account.
The cooling factor is not set automatically or adjusted during tuning. You have to configure
the correct cooling factor manually by using the ratio "Heating actuator gain/Cooling actuator
gain".
Example: Cooling factor = 2.0 means that the heating actuator gain is twice as high as the
cooling actuator gain.
The cooling factor is only effective and can only be changed if "Cooling factor" is selected as
the method for heating/cooling.
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Function Manual, 03/2017, A5E35300227-AC
PID control