THCAD-10

I have tried hooking up a 9v battery but was not getting any reading in the hal meter, I think maybe the comp I was using was not enabling things until velocity and arc ok etc was on or above a threshold. I also though I would need to set a different voltage dependant on the power I was cutting at.
I have a pilot arc torch with blowback so no hf issues and also a built in 33:1 divider so should be good without resistor.
I will type your config in tomorrow and try a cut see what happens. Failing that everyone will have to have items made from plate thick enough not to warp

Thanks for the help will let you know how it goes

Darren

you need to trace it through. Can you see the frequency on the encoder? even at 0 volts you should see a frequency. I think you are jumping ahead of yourself. Take the time to trace it though. go back to my post with the connection sheet of my setup..

When stuck on configuration issues please post your .ini and .hal files.

John

Hi Rod

I will have a look at your comp tomorrow. I had seen it earlier today but thought it only hooked into a comp written by Dewey.

Hi John

I reverted back to the hal pncconf created after the machine crashed. I have attached that here. I will attach the Ini when I am back a the machine tomorrow.

Darren

Thats not particularly useful. To get a plasma machine, you are going to need to edit your hal file by hand.

Remember, we can't help with physical wiring etc and the first step is to confirm that you hardware is tested in halshow to make sure its doing what it should be doing before you start building a config in hal.

Hi Rod

Sorry, not been able to get online for a few days. I have a couple of hours free tomorrow so will be back to the THC. I currently have a fully working plasma, other than the lack of thc functionality.
I am fairly sure the thcad is correctly wired and I am happy to hand edit the hal and any other files as needed.
I understand that the thcad takes a divided voltage from my plasma, converts that to a frequency, and that frequency can be read by the encoder in Linuxcnc, this can then be used to control the Z axis in an effort to keep a set voltage by varying the height of cut. I also understand there are a number of custom components that people have written that can be used for this purpose, and also the code posted by Islander261 that uses the built in scale component to achieve the same thing.
Tomorrow I will try again connecting the 9v battery and see if I can find a reading via one of the hal tools. I am assuming that I will need to use one of the previously mentioned components in order to see this ?

@Dee,

if I can find a reading via one of the hal tools.
If you use halmeter you can click on monitoring the signal for value changes.

In halmeter search for your mesa input pin. It's somewhere in the list.
Good luck !!

At the minimum, to check the THCAD, you will need to:

1. Specify at least one encoder in the driver (hm2_pci or hm2_eth) command line.
2. Set the encoder to up/down mode (quadrature mode is default)


The hostmot2 manual page describes both of these settings

Thanks both, I will look at the manual and give it a try tomorrow