Need Help

[jcbvh 0]

Alright guys. I feel like a idiot asking this What does the Circle with the "-1" before the OR/AND gates in this drawing means? Back ground: PLC 5, The inputs are from Emergency Stop pushbuttons UPDATE: Drawimg removed...We agree, that it is a NOT. Thanks Guys Edited 25 Oct 2013 by jcbvh

[drx 2]

Hi, which standard is that ? It really looks like an NOT gate though I can't tell for sure as I've never seen one like this, but considering the other gates are not fitting any standard neither, the NOT seems very plausible. Edited 25 Oct 2013 by drx

[PLCMentor.com 60]

Yeah that is an interesting drawing. I would also guess that it is a NOT function.