[GUIDOSAN]

This is a cnc router build. The four motors are up and running fine. I've cut and everything appears to be ok so the outputs are working fine and the board is enabled.
My problem is connecting inputs. I can't get the inputs to communicate so I can wire in the estop, limits, and homing.
I planned on option two from the Mach 3 manual. Pin 10 would be E-Stop, Pin 12 and 13 would be the Z and Y and pins 11 and 15 would be the home switches for the slaved gantry motors (X).
The switches are installed and operate logically with my continuity tester as NC circuits.
I was using an older c-10 without the jumper to pull up/down the inputs and having no luck in getting a response after settting the pins and ports and triggering the switches. I toggled between active high and lo with no effect.
I installed a newer C-10 with the jumper to pull inputs signals up/down with the same results.
Both boards were configured with pins 2 to 9 as outputs.

I'm missing something but I can't see the forest for the trees.

Guy

[GUIDOSAN]

I was advised to set the jumper on the c-10 to pull down and use the 5V and input pin as the connection for the estop and other limits. In the Mach 3 config I set the pins and active lo.
It works great with pins 10 and 15. The others don't create a trigger when making/breaking the connection.
any idea why three inputs wouldn't respond?
Guy

[john-100]

Hi Guy

how do you have the limit and home switches wired ?
and what test equipment do you have ? ( a multi-meter will be a good start )


I'm sure all 5 inputs go through just one of the four 74ACT245 IC's on the C10 board

if you can post pictures of both sides of your new C10 board so I can add the IC pin numbers to test for each input on the board

Attachment 259764

with the input jumper selecting the pull down input resistors you need the E- stop and limit switches to normally connect +5V to the input terminals

you should then be able to prove you have +5V at the IC output pins
the output pins are connected to the printer port via 39 ohm resistors (once the board is traced they should make easy test points )

when a switch opens the corresponding IC out put should go low


John


PS- I'll down load the C10 manual to check on the setting of the jumpers

PPS - added C10 input diagram

[GUIDOSAN]

Thanks John,
I have a pmdx-111 parallel port monitor that shows me what pins are logic hi. I'm not running through the switches to eliminate them as a possible problem.
Pins 10 and 15 operate as expected but 11 and 12 are high continously. 13 never goes hi. Since chips are cheap I ordered a set to see if that is part of the problem.
I don't know if 11 and 12 being high continously points to a different problem. By continously I mean even with the cable to the c-10 disconnected.

[john-100]

Hi

I've had a look at the pmdx 11 1 web page It looks like a very handy piece of kit



while your waiting for the spare IC's to arrive you could swop the IC for the faulty inputs with one of the other 74ACT245 to prove the IC is faulty


using photos off the web I've worked out which IC is connected to which printer port pins


Attachment 260138





John

PS this is the data sheet that should of been attached in post 3 !

Attachment 260164