Re)Start Protection - Siemens SIMATIC PCS 7 Operating Manual

7.5.2

(Re)start protection

If the process does not permit the safety program to start up automatically with the initial
values, you will need to program a response to F-startup.
The F_START F-block is used to signal an F-startup of the safety program with the initial
values. The COLDSTRT output parameter tells you that an F-startup has been triggered.
In this example, a flip-flop is set when the F-program is started up, which passivates the
output drivers. Once all the process conditions have been fulfilled, the operator can release
the F-output signals by resetting the flip-flop using the F-acknowledgment function
(F_QUITES block).
Note
For more options when programming (re)start protection, please refer to the "SIMATIC
Industrial Software S7 F/FH Systems – Configuring and Programming"
(https://support.industry.siemens.com/cs/ww/en/view/101509838) manual.
Compendium Part B - Process Safety (V8.2)
Operating Manual, 07/2016, A5E35031794-AB
Configuring the safety program
7.5 F startup and (re)start protection
105