Hypersensing questions

rodw wrote:

snowgoer540 wrote: SomewPlasmac here I read that Plasmac can be configured to fall back on the float switch if the ohmic doesnt trigger for some reason. Is that done by default, or do I need to do something to my config to get this to happen?

As Tommy said this is done for you by default. With pending changes to the Plasmac probing algorithm to speed up probing and to reduce the number of probing errors, the float switch may become a requirement so that there is room for the torch to slow to a stop when the ohmic probe is triggered without breaking anything (Or a float switch is required to implement the new probing algorithm).

Please report back when you are up and running so the feedback can be incorporated into the component. Once we get this proven with some feedback, we should be able to get it deployed to V 2.8 as well.

Good to know. My float switch throw is very short, probably .030-.040... hopefully that doesn’t become an issue.

I enjoy testing things and finding bugs so if there is anything specific you want me to focus on, please let me know.

That throw should be fine. The torch needs that movement to decelerate to a stop at the ini file acceleration setting when the ohmic is triggered so you can control that with your probing speed. Faster = more travel.

you can control that with your probing speed. Faster = more travel.

Not quite right, Probe Speed only comes into play after Probe Height is reached. It uses Setup Speed from the config panel to get to Probe Height.

From the yet to be completed docs:
The following formula can be used to calculate your machines approximate overrun.
0.5 × a × (v ÷ a)²
a = acceleration in units/sec²
v = velocity in units/sec
So with Z axis acceleration of 2000mm/s² and Z axis velocity of 33.33mm/s we would have an overrun of 0.278mm.
This is roughly 78in/s² and 1.3in/s for an overrun of 0.01"

acceleration is obtained from MAXIMUM_ACCELERATION from the joint associated with your Z axis in the .ini file
velocity is Setup Speed in the Config Panel divided by 60

In addition to changing the "num_encoders=" to 2 in the top of the main hal file, another critical piece of information is that you need the other setp values that are similar to the THC:

setp hm2_5i25.0.encoder.01.scale -1
setp hm2_5i25.0.encoder.01.counter-mode 1

I am honestly not sure if you need the filter or not (setp hm2_5i25.0.encoder.01.filter 1)? I've always been a little fuzzy as to what this did?

I think I read somewhere the filter was ONLY for the 7i96... but I could be wrong. Note that I DO NOT have an Ethernet setup, I am using a 6i25 with a 7i76 with Peter's custom Plasma firmware...

The filter bit increases the digital filter time constant on the encoder inputs
(from the default of 3 counts to 15 counts of the encoder sample clock).
If you are using a THCAD with divided frequency output (1/32 etc),
you should enable the filter to improve electrical noise immunity

Ok, I must be missing something. I've attached my hal files, and my ini for good measure.

Basically, I have the encoder showing the velocity in the hal connections. I can touch the two wires together and see that the frequency changes to near the max on the card. But nothing I do in Plasmac shows ohmic probing is enabled.

Here's how I'm checking:
enable ohmic probing checked
short wires
click test ohmic... nothing lights up

Here's what I've done
change numencoders to 2 in the main hal file
copy Rod's info into the plasma_connections.hal file
changed the frequencies to match my card

I think that's it. I did run Phill's configurator on a whim, and tried adding the hm2_5i25.0.encoder.01.velocity to the ohmic probe hal pin (in). The ohmic probe enable hal pin already said: ohmicsense.is-probing I am guessing since I added Rod's stuff.

Anyways, I appreciate any insight, as always. I think I'm pretty close to having this working.

EDIT: Uploaded a newer plasma_connections.hal based on Peters feedback about the filter