Siemens SIMATIC S7-1200 Function Manual page 192

Using PID_Temp
6.4 Cascade control with PID_Temp
Example
The following block diagram shows a cascade control system with PID_Temp using the
simplified example of a chocolate melting unit:
The PID_Temp_1 master compares the process value of the chocolate temperature
(TempChocolate) with the setpoint specification by the user at the Setpoint parameter. Its
output value OutputHeat forms the setpoint of the slave PID_Temp_2.
PID_Temp_2 attempts to regulate the process value of the water-bath temperature
(TempWater) to this setpoint. The output value of PID_Temp_2 acts directly on the actuator
of the controlled system (heating of the water bath) and thus influences the water-bath
temperature. The water-bath temperature in turn has an effect on the chocolate temperature.
FAQ
For more information, see the following FAQs in the Siemens Industry Online Support:
● Entry ID 103526819 (https://support.industry.siemens.com/cs/ww/en/view/103526819)
See also
Program creation (Page 193)
192
Function Manual, 03/2017, A5E35300227-AC
PID control