Hi all,

I'm hoping to put home switches on a generic 3020. The stepper controller board (JP-382A) attached is enclosed in a black box. The limit header and corresponding optos are shown in the red boxes - at least I thought so. Continuity testing between xyz pins and the optos give around 5k, which is surely way too much to drive the led. I did not want to remove the board to trace, so wondered if anyone knew what was going on?

Another problem is the dc jack output and possibly corresponding opto labelled 'probe' in the blue boxes. I asked the manufacturer about that and they said it was for a 'Knife Block', but my machine does not have this. I'd been hoping to use it for the auto level, but am not even sure what a knife block is.

That should of been all the questions, but have just seen on the photo that the opto labelled ENO (to left of limit optos) appears to have a broken pin?! Have already tested the machine ok, but maybe I broke the pin during continuity test. Seems weird - so wondered if anyone knows what the ENO opto is for?


JP-382A