Emergency STOP and power -up

Dear colleagues


I am learning to program siemens plc.

I have a problem with how to solve the problem with a power outage and emergency STOP.

A colleague told me he uses OB100 on power up and then the program continues
(he put into OB100 marker).

He also told me that in the program (which I added in the attachment),
he connects the signal from OB100 together with the emergency STOP.



I got lost in writing the program.

I would be grateful for your help with the explanation.




I have a question how to attach the entire program with TIA PORTAL V16? I can't attache because the size is to large.

I am not quite following so here is a general answer.
Set all process values, that need to be maintained in case of power loss, as retentive.

Use OB100 which runs only once on startup, to initialize some data with specific values or to do something with the retained data if needed.
E-Stop should not turn the PLC off and it should in itself (its circuit) render the machine safe including disconnecting power to output devices if that makes them safe. In addition to that the PLC logic can reset the outputs (and any other tags or data) on loss of E-Stop and sets or initialize tags and data on E-Stop signal being restored.b

Thank you

I agree with kalabdel, What I have done before is as suggested, i.e. make things that need to be stored retentive, I usually "HOLD" the process i.e. have a hold routine or bit that stops any energisation of outputs This is set in the startup (power up) or by E-stop or stop button, so in the event of any of the preceeding, the process is held until resumed by the operator (providing all other things like E-stop have been reset etc).
The other things to consider are an Abort could be just reset everything, a routine to bring a machine or process back to a starting position, it will depend on many factors like is the process recoverable from when it stopped.