Solution fo "hm2 error finishing read" with no good PC

-no grounding
-bad/looped grounding
-bad/weak power supply
-error in wiring
-EMI/interference from drives/VFD
-PC with no ground connection
In that order, mostly.

i will check.
the mesa card should be wire with the ground ?

Look like more than just EMI causing lost Ethernet communications.

It actually it looks like the 7I97T card lost 5V power briefly,
since it does a full reset. I would check the 5V supply voltage,
current capability and connections.

In addition to tommylights suggestions, you might check that the contactor
contacts have arc suppressors, especially if they switch inductive loads.

well, I'm trying to locate the trouble, it's with the encoders: when I unplug them, there doesn't seem to be any restarting, and when I plug them back in, the default comes back from time to time.

my encoder is power by 5V

Could it be the power supply or the encoder ground?

below, is the power supply for the 7i97t card too weak?

 

I would say that power supply is marginal

I would get a DIN mounted PS say a MDR20-5

Older encoders may draw considerable current

Noooooooooooooooooo!!!
Never use those power supplies for anything, ever, except powering LED lights maybe.
That is a non regulated transformer power supply with no output control at all, so voltage varies wildly with load, and is way above 5V at low loads when set to 5V.
Or look at it the other way, never use a 3$ power supply to power 1000$ equipment.
Get a MeanWell or Delta 5V power supply, at 20-30$ they are still cheap and can be found easily online.
In the meantime, if you have an old Samsung 5V charger, they were really good, the original ones, not the counterfeit ones.

it's not common to have a 5V power supply, I'm going to order one, too bad it's not 24V because I have lots of power supplies .

I replaced the power supply with a laboratory power supply (variable voltage).

It seems to work!

thanks for your advice!