Controller build for Plasma

xnaron wrote: What is the thinking behind the optional ac relay to switch the power on and off for the ohmic probe?

PCW said leave it out. I had heard reports of corrosion in the tip if it was left powered up on a water table 24/7. PCW then said to switch the AC power and I had an AC relay handy.

Currently I have bypassed the relay.

I really wanted to leave it on all the time once the machine had come out of estop. I have had trouble finding a pin that does this where I want it. Usually I'd use the spindle on signal but the probing happens before then. I have tried using the motion status pin but it missed the first probe for the same reason.

I just thought then there might be an estop-latch pin I could use.

I don't understand why you would want it on all the time but you could use halui.machine.is-on

Thanks. For my table this would be less of a concern then as I only turn it on when I am going to cut. I can add one later if it becomes an issue.

Here is how I have the ohmic probe wires run. Using 22 gauge and they run along a couple of other inputs. The terminal blocks with the arrow will be where the ground and resistors for the ohmic terminate. Anyone see any issue with the wire size or placement?

rodw wrote:

xnaron wrote: What is the thinking behind the optional ac relay to switch the power on and off for the ohmic probe?

PCW said leave it out. I had heard reports of corrosion in the tip if it was left powered up on a water table 24/7. PCW then said to switch the AC power and I had an AC relay handy.

Currently I have bypassed the relay.

I really wanted to leave it on all the time once the machine had come out of estop. I have had trouble finding a pin that does this where I want it. Usually I'd use the spindle on signal but the probing happens before then. I have tried using the motion status pin but it missed the first probe for the same reason.

I just thought then there might be an estop-latch pin I could use.

I used or2 so it’s on via the ohmic comps rules (believe that’s when the program is running), and then when the Plasmac GUI calls for it (probe test or ohmic test, etc). Then it’s off when the table is idle.

I have a hard time believing the corrosion would amount to much if anything but it works how it is for me so might as well leave it.

phillc54 wrote: I don't understand why you would want it on all the time but you could use halui.machine.is-on

I thought I tried that but it was ages ago. I wanted that to simplify trouble shooting. The Hypersensing negates the need to use the seperate ohmic enable signal that was designed for the earlier relay circuit from theislander261.

@snowgoer, I think I set it up so it or2's two signals internally and use its own relay on signal. This is one area I wanted to clean up. One day!

rodw wrote: @snowgoer, I think I set it up so it or2's two signals internally and use its own relay on signal. This is one area I wanted to clean up. One day!

I’m not sure I follow? But like I say, it does work fine/how I expect it to (on during the entire program, and on when I click the buttons)

Don't change it then!

@Phil, it comes back to me now, I wanted to turn it on only while a program was running....

rodw wrote: Don't change it then!

@Phil, it comes back to me now, I wanted to turn it on only while a program was running....

Maybe that’s why I’m confused. I thought that’s what it does currently?!

Getting there. Need to get the door on and wire up the other 24V supply.

Outstanding questions:

Ohmic probe wires routed along other inputs and 22 gauge. Concerns?

xnaron wrote:
Ohmic probe wires routed along other inputs and 22 gauge. Concerns?

No concerns if they are properly shielded. Shielding should be grounded only on the electronics side.