Torch On HAL Pin when using 7i76e

rodw wrote: On the mesa product page, there is a zip file that includes lots of bit files for different configs. the one to use ends with pl.bit (where pl = plasma)

You need to use mesaflash to burn this to the 7i76e
I do show how to do this in my video

Thanks again Rod! I will let you know how it goes tomorrow.

rodw wrote: Ok, because you are using a downdraft table and don't have to contend with water splashing around, the best course of action is to use the original ohmic.comp that is part of the Linuxcnc deployment from 2.8 and up.

You have no need for all the fancy crap Ohmic3 does to try and work around the water table problems where the voltage drop can be less than 1 volt between the probe on and off.

The correct pin name for ohmic sense probing is

Code:

ohmicsense.ohmic-on

The documentation is here linuxcnc.org/docs/devel/html/man/man9/ohmic.9.html
or available if you type

Code:

man ohmic

The suggested connections in your machine.hal file are shown in the documents. Note that on a new installation, the last line

net ohmic-true ohmicsense.ohmic-on => plasmac.ohmic-probe

will be added from pncconf or the Plasmac configurator so it should be omitted

These pins control the voltage threshold:

Code:

setp ohmicsense.threshold 22 setp ohmicsense.ohmic-low 1

In this example, the probe comes on when the voltage is > 22 volts and goes off when its < 1 volt.

I would jog the torch down so it touches the material and use halshow to review the voltage on this pin

Code:

ohmicsense.ohmic-volts

before setting the upper threshold. On my system I always get 24 volts so a threshold of 22 works for me but you may wish to set it lower (18v maybe?)

And yes the relay to turn the AC side off is optional. I think I have bypassed the relay.

The only reason to turn the power off is becasue there have been some suggestions of the possibility of electrolytic corrosion inside the torch tip on water tables (water shorting out the internal contacts) when machines that are left powered on while idle for long periods. But because you have a dry table, this will not be an issue for you.

So in your case, keep it simple, leave the relay out and just turn the power supply on when you power up the machine!

This is the error I am getting:

twopass: Error in file ./mark_i_connections.hal:
setting parameter 'hm2_7i76e.0.encoder.02.scale' to '-1'
parameter or pin 'hm2_7i76e.0.encoder.02.scale' not found