7i96s Arc Voltage + Encoder Fault

Thank you for your advice!

The THCAD is mounted inside of the plasma source near the control board.

I'm making the recommended change for a plastic box outside of the plasma source.

This is the first Thermal Dynamics equipment that I work.
I've worked with several Hyperthem plasma cutting systems. All of those got an THCAD inside working well.

The THCAD boards seems to be fine. I have to check the encoder inputs from 7i96s but appears to be usable.

I am making that change to the future plasma systems to guarantee the best care for the boards.

When I have the chance I will make the changes and update you.
Thanks

So I was able to double check for short/faulty cables on P1. I've disconnect the encoder connector from 7i96s and no contact to GND.
Made the change of the location of the THCAD board to the outside of the plasma source in a plastic box.
Connected the shield only on the 7i96s side in the pin TB2.9 with the GND cable.
When I turn on QTPlasmaC the value of Arc Voltage is 145.
The encoder velocity pin seems to be working fine on halshow.

What you recommend to do?

Thanks in advance, really don't understand what's happening.

Ok, PCW was telling that should be terminated at 7i96s. Can make that change.

The encoder velocity has consistentely fast changes.

Note: I was able to make the bit file changes to add 3 more encoder in expansion port. 
This video was really helpful:

sharp_reaper wrote:

When I turn on QTPlasmaC the value of Arc Voltage is 145.
The encoder velocity pin seems to be working fine on halshow.
 

Sounds like you have not correctly calibrated qtplasmac for your THCAD settings
The THCAD 0 volt frequency should be what you observe on the encoder velocity pin give or take some bouncing around.
This offset needs to be entered in qtplasmac.

If you read the QTplasmac docs, there is a link to a calculator to determine your settings.

If you read the QTplasmac docs, there is a link to a calculator to determine your settings.

I'm using the calculator from the PNCconf. 

SOS UPDATE:
Changed the THC to THCAD2 and change for a divided arc
Put the THCAD2 outside the plasma source in a plastic box.
Shielded only on THCAD2, in new cables. 

Made the changes that you recommend:
   

Results:
This worked a week, but it happens again. The arc voltage is on -45.

I can take more pictures, make video. If anyone can help.
 

Now you have a THCAD 2 you can do more tests.
But normally, you would set the THCAD to use 1/32 frequency. This would alter your offsets etc accordingly. Make that change
Assuming a 10 volt range, apply a 9 volt battery to the THCAD  HV input. The flashing light should change frequency. Does it?
the voltage should be about  90% of your full volt range. Is it?
What are the calibration frequencies for your THCAD on the sticker?
Read the encoder velocity at 0 volt at rest and at 9 volts.
What are these readings?

Thank you Rod for your advice.

I'm testing when I have the chance. I can put the 1/32 divider frequency. I'm used to THCAD300 and always put on 1/128.

The sticker value for my THCAD2 is: FSV - 899.4 kHz | 0V - 96.8 kHz

The initial value for the offset was about 700 but I've noticed that when the Power Source is Down (No Power) the arc voltage is 0V. When I turn On the arc voltage goes to 12V.

Checked the encoder velocity pin with the value of 900. Put 900 in the offset. Arc voltage has 0V and got decent results.

Made some tests today. When I make the first pierce the arc voltage, in the first moments turn in -73 and then goes back to normal value.
After that the pierces (should be a higher value than the Cut Volts on material) seems normal to me.

Talked with the supplier of the plasma source and he refers HF equipment and to check the grounding. Reinforced the grounding connections which has a good grounding less than 0.3 Ohm.