Lack of pins on parallel port. Replace estop?

Hi everyone!
I've just bumped into a problem with a lack of input pins on my parallel port. I'm trying to convert my gantry mill machine into a
universal one so I could use mill and a plasma cutter when I need that.
So I've build my own THC board which can emit 3 types commands UP / DOWN / ARC OK over 3 wires, of course.
I'm planning to use a pin that is used for a touch off function of my mill config as an Arc OK pin for a plasma one. One of the other input pins is used for limit switches and so I only have 2 input pins left. One of them (10th) I can freely use for an up or down signals but the last one (11th) is used for an estop function in the machine's hal file like this:so when I send any signal to it the machine turns off (obviously).
I tried to disable estop pin by commenting this line out. But I can't turn on my machine after that at all. Even the software button in the UI is disabled.

So my question is is it possible to remove / replace this estop line with something (I don't know what) but still be able to turn the machine on and off from the EMC UI?

p.s. I only have one parallel port and I have no possibility to add another one right now because I need to solve this problem as soon as possible and I have no time to wait for an extension PCI board

Regards, Konstantin

You can get all REF and Home switches to one PIN

as you have 5 inputs 12/5 12outs 5 in
the THC will work

also no need for ARC ok
as you can get thcup.arc-ok to M3
the THC itself as of proma will wait 2sec till it moves if needed

Ok, that sounds reasonable in my case. Even though limit switches and estop work differently, but I really am not using them as home switches, so they all can be connected to the same pin

also no need for ARC ok
as you can get thcup.arc-ok to M3
the THC itself as of proma will wait 2sec till it moves if needed

What if arc is lost? I need to stop program execution and fire it up again, that's why I need to have this signal, am I right? I've never used plasma cutter before so I might have some misconceptions about this.

Another way you could use a pin for more than one purpose is to set a pin using M62-M65 in gcode and connect that output pin to a MUX2 to swap pin signals on that command. You might be able to use this when probing for instance.

It would be interesting to see you could use the plasmac config with your THC. So far most people have been using a mesa THCAD board but it has a mode to support your style of THC. Whilst this requires a recompile to include the reverse run branch that is not yet in Linuxcnc master branch, you could run your existing mill subject to the usual changes required to move from V 2.7 to V 2.8 for independent axes and multi spindle support.

Most plasmas will need the arcok true for the entire cut or they will think the torch has gone out.

John

we got more then 5 Plasmas in use
all beside one build by the desesed Member here
and noone has a Arc-ok signal wire
it workes that way
IF the Torch does not fire (( hapens not offen on a 85A))
you will HEAR it quickly in the display where to restart NO problem

if the Arc goes/dies down as to many Water in the Nozzel during CUT
You can restart from last in Point OR manipulate the Gcode as you see the outpoint on Manuell jog
THIS Happens only on USER Fault / Meaning wrong settings
Nozzel to the Max livetime / Overcut speed / EP Time of the Cutter between Cuts

Another way you could use a pin for more than one purpose is to set a pin using M62-M65 in gcode and connect that output pin to a MUX2 to swap pin signals on that command. You might be able to use this when probing for instance.

It would be interesting to see you could use the plasmac config with your THC. So far most people have been using a mesa THCAD board but it has a mode to support your style of THC. Whilst this requires a recompile to include the reverse run branch that is not yet in Linuxcnc master branch, you could run your existing mill subject to the usual changes required to move from V 2.7 to V 2.8 for independent axes and multi spindle support.

It looks like too much work. Unfortunately I don't have time nor much of a desire to do all that

Most plasmas will need the arcok true for the entire cut or they will think the torch has gone out.

I'm developing a custom THC so it may or may not need anything

How about 2 pins:
1 = Up
2 = Down
1 + 2 = Arc OK
No pins = something bad happened.

Sounds good. Could you please elaborate on how can I hook it up in my hal file?
I only have 2 days left to set this thing up and I think I won't be able to read thru all the docs and understand everything correctly.
I think I need to use some AND logic to get signal from 2 pins at a time

@ andy
dipending on the THC in use
this will nor work as ther can be Arc-ok Faults on settings like from proma
it might be flickering so it stopt the mashine on arc ok

here arc ok is not connected at all and on normal part use it is not needed