Good afternoon to everybody,

I'm seeing a project already done, the "production line" is very long , for this reason is divided into zones. I have a function(FB) called "emergency Zones" where there are all the zones. In one the segments I have found the E_Stop function. The only thing I have got is the E_STOP input. There's a bit of a Safety DB that is a series of "Emergency mushrooms" actived. The ACK_NEC is a ALWAYS 1 bit, then the ACK input is called "emergency restore". I know what does it means "Emergency restore", but I don't get what does it makes the fucntion.

I know it sound a stupid question but just looking the segment I don't totally get what it makes.

Study of complete PLC logic will only find out how it is used. 

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