Siemens plc

[Spiros82]

Hi all i would like to post the next question.i have 7 plcs(siemens 1212c cpu) that must be able to run only if winncc runtime is active.My approach was that when the login screen of wincc runtime is loaded then it sets a n.o contact inside plc start running function.the problem is that in this way if a plc isnt powered on when runtime login screen is loaded and gets powered on later when the login screen isnt active anymore the n.o. cant be set and the plc cant run.Any alternatives?

 

[controlsdude]

Maybe your confusing system running start conditions versus PLC in run mode? I am sure you can have a plc tag interface with your wincc application where you look for a bit to be set from wincc. Use this bit not set to flag an alarm condition. And also use this wincc tag bit to qualify the plc that the system can be started.

Is this what your saying or please rephrase your question?