Weird intermittent bug involving proximity sensors and homing

Setup is : 5i25-7i77-7i84-Gantry – AXIS 2.8.0.pre1.4625-g8f279b8

I have a weird intermittent bug that involves homing, and when I have this bug I cannot use the homing to square the table so the cnc becomes useless. Major bug.
It was working fine for 2 years but every once in a while had the bug … rebooted and restarted everything a couple of times and it re worked … now it is not …
I have trace it to the input of the 7i77 card and I was getting ready to displace them on the 7i84 … not remembering how to address it in HAL … for the axes limit switches … that I did and saw this …

Picture of drives not enabled … proximity sensors functioning and reporting
Picture of drives enabled … proximity sensors not working but the triple edge finder triggers … go figure …

On both pictures, the red dot at the top on the right side is the Z-Home that is triggered (the other red dot besides it is a reflection on the motor)
When the drives are not enabled, they appear functional; the HAL configuration WATCH screen has the hm2_5i25.0.7i77.0.0.input-07-not reporting live and correctly. All other input also work fine when the drives are not enabled.

The minute I put the drives ON … HAL configuration WATCH screen is dead on that input … whatever I do … the sensor trigs, the relay too, not the input … but the triple edge finder is responding … hm2_5i25.0.7i77.0.0.input-31 is still live and correct.
So when I put the drives ON, I loose proximity sensors … why …
Anyone has any ideas that might help ? no homing = no cnc …
Mike.
P.S.: I did not find any info in HAL configuration on the 7i84 … is it the
hm2_5i25.0.gpio.000 and so on ?

Sounds like a electrical noise issue, Have you made ANY changes to the machine since it was working better before?

Double check your grounding, looking for possible ground loops. or other grounding issues.

Are you using shielded cabling?

Do the drives or their power-supply need to have a noise filters added?

Mike@CNCproCuts.com wrote: P.S.: I did not find any info in HAL configuration on the 7i84 … is it the
hm2_5i25.0.gpio.000 and so on ?

No, the 7i84 inputs will have names like "hm2_5i25.0.7i84.0.0.input-00"

You should be able to find them in Halshow

about the 7i84 ... I don't see it in Halshow ... grrr

My drives are 1.8kw and all of them has noise filters. ground loops ? would a ground loop work for a while and then stop working ?

Hitting the stop button disables the drive and then all sensors work ... very weird to see things light up (when homing the Z and it does not react I use the E-Stop)

I'll include a picture of the control box ... give me a sec

what bitfile did you flash to the 5i25

Here is my control box and the CNC it controls ... both my own design and fabrication

Can't say ... how can I verify ? (about the 5i25 flash ...)

Can you measure the 7i77 input 07 with a voltmeter relative to field power common
in both switch states and both drive enable states?

That is measure from TB8 pin 8 to TB2 (orange) pin 8 in all states

If you had a noise issue with serial communications I would expect to see
error pop-ups in axis

That looks like an imminent fire hazard !
As Todd mentioned, that is a noise issue form motor drives, and after looking at the pictures that is the first think to look into. Grounding problems can occur in many ways, but from experience the first thing to look at is : did you change the power outlet ?