SFC Initialisation

PLCnext Engineer
1

Hi,
I’m currently trying to do the following thing on the SFC add-on :
An emergency stop is activated, i set my SFC to HALT mode,
Then a button ‘Reset’ is push, the SFC come back to step 1.

I found how to set to HALT mode, but i can’t find how to put the SFC to step 1.
How can i do ?

2

Here is the answer from the PLCnext Engineer support team:

if you set the variable to “Halt”-Mode you can operate via. the inputs
Step_ID and Activate_Step to the first step for example.
The right Step_ID can be select below the struct Step_States.

Important:
**The ID can be different to the Step count.**Example = Step 1 has ID 2?name=image.png?name=image.png?name=image.png
If you have additional questions do not hesitate to ask.

3

Hi Robin02,
first things first so check the help page for programming in SFC. You’ll find the FBs’ parameter description.
Then I would suggest something along this pseudo code:
IF ResetButton = TRUE AND SfcFB.Active_Operating_Mode = HALT THEN

//Go through all steps and deactivate them
WHILE(I < Step_States.StateCount) DO
SfcFb.Deactivate_Step(Step_States.StateList[I]);
I++
End_while

//Crawl through the structure and check the object property. Return the ObjectID of init step
InitStepID := FindInitStep(SfcFb.STRUCTURE);
SfcFb.Activate_Step(InitStepID)

End_If