ANSWER:
If you are regulating the pulse with pulse width modulation, the controller variable is converted into pulses on a rapid call level. This puts a considerable load on the CPU. To avoid this loading on the CPU, pulse width modulation can be decentralized to the ET 200S with the "2 PULSE Module".

The SIMATIC Standard PID Control and Modular PID Control software control packages and the controllers integrated in the STEP 7 "Standard Library > PID Control Blocks" are suitable for this.

Please note the following points for linking the software controllers:

• Use the "2 PULSE Module" in "Pulse Width Modulation" mode.
• Use the "LMN_PER" variable output with the software controllers.
• For the "PWM Output Format" in the "2 PULSE Module" you must set "SIMATIC S7 Analog Value" accordingly.
• The period should be selected to match the scanning time of the controller.
• To increase the resolution, you can use 0.1 ms as the time basis.

Keywords:
Software controller, Controller module