JCBIII

roger that. Sounds Like Ive basically got it right then. The E-Stop dumps air pressure, and there is no high voltage to worry about anywhere. So the logic resets the plc to a safe re-start condition basically.  I have a 5 amp e-switch so Im going to go ahead and run all 24v power through it (with the exception of the plc itself)  That'll take care of both power and air.

Hey folks.  IF anyone here has just a second, I have a very simple PLC program, but it's the first one I have ever done and I want to make sure its "done right" ...or at least that I have the right idea even if I need to change things. I basically watched Automation Directs Videos for 2 days and then wrote this.   The program simply uses a start button to  start a drum that fires 3 air cylinders in a sequence. the complete bit resets the drum.    The question is have is with the e-stop circuit.  To follow OSHA guidelines of "denergizing the device"  when the e-stop is pressed, what i have done a #1, connected the main air dump valve in series with the e stop switch (non plc controlled in other words)      and In the PLC i put in 5 or 6 E stop rungs, that reset the control bits, and reset the air cylinder coils.   I did all this in the main program, I'm not sure if that's the correct place or if I should of done an interrupt or something.  (deactivating the cylinders wont cause anything to drop or anything) Anyway looking forward to your input always trying to learn.  oh one other question.  Should I also wire the 24v to my  air solenoids through the e-stop as well or is logic good enough? Insert Press.ckp