My workplace had a visit from a Health and Safety inspector a while back, and despite our ShopBot being housed an enclosed in a room, we were asked to install a safety mechanism to stop the CNC from operating if anyone opened the door to enter the room.


I should point out that I am in the uK and there are some quite strict Health and Safety regulations, so if an inspector officially asks you to do something and you don't there can be legal implications. We have a PRS Alpha purchased in 2008-9.


So I got hold of a magnetic safety switch that has been attached the door, and a relay that I have installed in the control box and connected to input 5.


Initially I wanted to use input 4 as I read in the documentation that it acts just like pressing the space bar. I assumed that meant that when input 4 is triggered the CNC would stop and you would receive the same message has hitting the space bar.


I wanted the option of resuming the cutting file instead of having to reload it and restart it from the line it was last on. Unfortunately I can't get input 4 to work.


I connected a simple switch to the input 4 terminal and ground, but there was no response from input 4. I tried setting input 4 to Normal Open and Normal Closed but still nothing. The input 4 indicator is dark green and the number 4 is red, not sure what that indicates.


Have I misunderstood being able to use input 4 in this way?


If I can get input 4 to work would I get the same options to restart the cutting file as hitting the space bar?


Sorry about the long post.




P.S I did try to post the same question earlier but not sure what happened to it....