Plasma cutting with servo System in LinuxCNC

You may be able to switch this with the 7I77's
Spindle enable signal. This is an OPTO-Coupler
(isolated) transistor output but you would need to
know how much current is required

The 7I77 enable output is rated at 50 mA max, 100VDC max

you could measure this with a DVM on current range

Ok. output enable 5 right? Thanks, it is a good idea.

Yes the other ones are no good as they are all switched in common
(this also assumes that you do not need analog out 5)

Ok. I have dude. Why use a THCAD card if power max 45 has analog output and it can be connected to analog input of 7i76 card to control of height. why is necessary THCAD?

Other question:

Ok all the hardware is right but what with the software? What CAM System is posible used with this?

good point about the voltage output of the powermax they have the builtin voltage devider with a max output of 18 volts (i think this must be with the divider set to the lowest setting from memory this would be 20:1) i think so the input voltage of the 7i76 is 36.6 volts but the issue maybe the refresh rate of the input

also if i remeber the powermax 85 i have states a dry contact closer to start the torch i dont think it mentioned a voltage tho so am unsure here i was under the impression that it was just logic signals

The analog inputs of the 7I76 are pretty crude so 18 V would be about 1/2 scale
of an 8 bit converter so only 7 bits or about 3V resolution (steps).
This may be OK for a THC, dont really know.
There's no problem with 7I76 analog input refresh for THC usage. it runs at the servo thread rate.

A tradeoff with using the 7I76 inputs for THC voltage measurement is that now the
plasma power supply GND is common with your limit switch and output common.
Plasma power supplies tend to be pretty dirty EMI wise so this may not be desirable.

The THCAD has close to 10 bits of resolution at 1 KHz so more like 0.25V resolution and
0.1V is achievable at 250 Hz sample rate.

In conclusion is better THCAD because it has better sampling rate and isolate noisy signal of plasma supply. Now what with the CAM software to plasma?