PM45xp "transfer" signal issues

[SENSEIJIMMYRIG]

Hi everyone I am building my own plasma but cant seem to get the transfer feature to work.
My pin is pulled high and suppose to be pulled to ground by the pm45xp.
Wiring is as follows. Pin 12 to ground, pin 14 to signal pin. If i manually short the pins (12 and 14) on my connector and reading the pin with linuxcnc halmeter it changes from true to false. So everything on the software/wiring end seems to be working just fine. However when running the torch it never changes from true to false. What could I be missing? The only thing I suspect is a solid state relay that cant make a ground connection and I need to have the pin pulled low by default and pass 24vdc+ through the relay to signal on. Figured I would ask here first before I started rewiring.

Everything else is working just fine, I've cut a few 8x4ft sheets of 16ga and tried 1/8in last night but my pierce height macro doesnt work without the transfer and struggled piercing at cut height with 1/8.

Thoughts?

[robertspark]

The transfer signal is not pulled to ground within the hypertherm

Inside the pmx is a relay essentially that just closes the two contacts for transfer.


How you wire those contacts is up to you..... 24v via a resistor on one side and vround on the other side, with the 24v input being routed to an input pin on your breakout boars or mesa hardware is all down to you

[SENSEIJIMMYRIG]

Maybe I wasnt clear. Pins 12 and 14 are the transfer relay for the powermax 45xp. One pin is connected to my board's input, the other to ground.....so if the relay were to fire it should connect the input pin to ground (and if i short the pins it does indeed flip the pin low).

Just got a testing procedure for the relay from hypertherm going to test that now. Will report back with results.

edit: Welp I checked the port with a multimeter per hyper therms instructions (continuity test) it is working great, nothing wrong with the pm ]45xp.... not sure where to go from here. Will double check everything.

[robertspark]

I'd suggest you need a reasonable current to flow through the transfer relay (i.e a reasonable pull-up resistor to 24V)

At a guess.... I would use something like 1x220ohm 3Watt resistor, or a couple of parrallel (2x) 1K ohm, 1W resistors as they will draw ~100mA or 50mA respectively through the relay contacts.

[SENSEIJIMMYRIG]

Will give that a shot, I had a 10k pullup (Forgot i'm not in arduino land anymore), will try a 2w 500 ohm pullup.

Thanks for the idea

[tcaudle]

The transfer signal should not need a lot of current to turn on an input to a logic pin . If its triggering the Hal pin then it has to be something in the settings. Inputs either work or they don't. Transfer is based on a min cut current at the plasma . That is all that is required. Is a basically a NO set of contacts that you can use like any input switch you have . If in doubt put a meter on the input as its running to monitor it. Better yet tie it up to +5 though a 1K resistor in series with an LED (anode end towards the plus voltage) then you can see the signal each time it triggers

[tcaudle]

Most BoB have pull ups on the inputs already and some even have LED indicators. That should be all you need. No external source of power (24v) is needed.

[SENSEIJIMMYRIG]

I'm using the ebay special BOB with relay and assumed, as you did, that it would work by default.....nope it needed the (used a 300ohm 2w) pullup to 24v resistor. After that it worked flawlessly thanks for the suggestion robertspark

[Rodw]

Awesome to see another person building a plasma machine based on Linuxcnc. There is a very active project on Linuxcnc called Plasmac which basically does everything you need for plasma cutting. I think all of us that have experimented with plasma cutting over the last few years Linuxcnc have adopted it and added our collective experience to Plasmac. Its in the main stream distributions for V 2.8 & 2.9. You can read about it here
http://linuxcnc.org/docs/devel/html/pla ... guide.html
More info on the Linuxcnc forum which now has a dedicated section for plasmac.

[SENSEIJIMMYRIG]

Sweet thanks for the heads up. Helped my makerspace a few years ago put a plasma together (4x4) and we are running 2.7 but with no thc. Built my machine a year and a half ago (5x10) with 2.8 cause i needed to home 2 axis independently but wasn't able to get a thc working. Just threw together an arduino analog to hz converter (mimicking the mesa thc) so will join 2.9 and join the forum over at linuxcnc. Thanks for the heads up. Ive been having issues where the arc goes out mid cut when the consumables get old (lots pf small parts on a 5x10 will do that) and would like to have the torch pause so i could replace and restart. Think i know how to do it with another thread reading the transfer pin but if it's been done will save me the trouble.