Resetting Functional Switching - Siemens SIMATIC S7-1200 Safety Programming Manualline

3 Methods for Safety Programming
3.10

Resetting functional switching

Safe actuators are frequently used for functional switching. The relevant safety
standards require that resetting the safety function does not trigger a restart of the
machine. When the safety function is triggered, functional switching must therefore
be reset and a new switch-on signal must be required.
Recommendation

Lock process control in the standard user program with the release signal from
the safety program. As a result, safe shutdown also resets process control.

Transfer the release signal from the safety program using a global data block
(see also Chapter 3.9).
Figure 3-15: Locking process control with the release signal
ProcessControl
start
stop
Safety Programming Guideline
Entry ID: 109750255, V1.0,
Standard user program
DataFromSafety
10/2017
Safety program
Safety
release
33