Another Input 4 question

We have a PRS Alpha ShotBot purchased 2008-9. We recently had a visit from a health and safety inspector and despite the CNC being in an enclosed room they wanted us to install a stop switch mechanism so the machine would halt when someone opened the door and entered the room.

I must explain at this point that we are in the UK and we have quite strict health and safety regulations that are enforceable by law. So to ignore a request from an inspector can result in fines.

We have installed a magnetic safety switch to the door and safety relay inside the control box and connected it to input 5. So this now works and stops the CNC etc.

My query is this; We wanted to connect to input 4, as in the documentation it states that input 4 works just like hitting the space bar on the keyboard. We could not get any response from input 4 so instead we used input 5. input 5 works but when the CNC stops the message that appears on the screen does not give us the option to continue the cutting file like it does when you hit the space bar.

When testing Input 4 there was no response. We wired a simple switch that would connect input 4 terminal to ground, nothing happened. We tried with input 4 set to normal open and normal closed. there was no change to the input light on in the control software and no interruption of the moving machine. Just out of interest the input light for input 4 is dark green but the number 4 is red, what does this indicate?

Does anyone have an idea of what might be going on or have we misunderstood being able to use input 4 in this way.

If we could use Input 4 would the message window on the screen be the same as the one you get when hitting the space bar?

Sorry about the long post.....