Home Switch Problem

Hi all, i'm having problems with the wiring of my home switches, mach 3 doesn't seem to recognise them in the diagnostic screen but they are working, but incorrectly, you have to press the the switch a couple of times before the axis stops. at the moment they are connected up open circuit, so when the switch is pressed it becomes live i have swapped the wires but to no avail. I have no idea whats going on and i'm not sure how to configure mach 3 with regard to the inputs and outputs etc
The switch is a mechanical lever type as shown. any help would be most appreciated
one wire goes to earth in the control box and the other is pin. pins used are X=13 Y=12 Z=11

Hi Kev

what breakout board are you using ?
and how have you wired the switches ?

it looks like you have wired the switches as normaly open
( if a wire breaks the control will never see a switch close ! )

John

Hi John the bob looks like this. I have tried both normally open and normally closed

looking at the breakout boards inputs

Attachment 21208

when the limit switch is closed, the EL817 opto isolator's NPN transistor will ground the printer ports input pin

the breakout board does not have any pull up resistors to ensure a printer port input is at a valid logic high when the limit switch is open

this can be a problem with PC's or laptops with 3.3V printer ports

John

Hi John, Im afraid I don't understand a word of what you've just said.....sorry!
Could explain please

Hi Kev
your micro switches are connected to your PC/Laptop printerport via opto isolators
(opto isolator part number EL817 - the terminal E goes to ground and C to the printer port input pin )

do you have a multi-meter to measure the voltage change at the printer port input pin when the switch is operated ?

how have you set up the switches in mach3's ports & pins ?
any thing like this -
Attachment 21210

John

Yes I've set the ports & pins and I'll check the voltage tomorrow
Thanks for your help I'll let you know how I get on

Hi Kev
printer port terminals
Attachment 21211

john

Morning John, yes the voltage on the pins are about 3.3 v
So what do I need to do next

Does the voltage change when you work the switch?