Measured input to IO LC1 card

[Wastle]

I Have 4 weighing systems, identical hardware and software, one of which has a weight display issue.

The reading whether empty or loaded fluctuates. I have measured the input to the IO LC1 card and it is steady to within a 0.1mV. What am I missing? the system has been calibrated, but doesn't improve it.

The other 3 system work fine.

[kratmel]

Usually I have problems with weight cells only.
They failed due to mechanical damage or shock load on the weight device.
Did you test the replacement of a module with bad behavior into a good module from a system that works fine?

Is it possible that there is a source of electromagnetic interference near the device?

[Ausman]

+1 to Kratmels suggestions.

Also, I know someone who had a weird issue and the cell was connected incorrectly, back to front I recall.  Was miles away in the bush, and he picked up the error looking at photos sent to him. Don't know the full ins and outs, though, just that it was a wrong connection.

cheers, Olfa

[Wastle]

There are sources of electromagnetic fields, but it doesn't bother the other systems.  I have already changed the module.

Out of interest(newbie here) I am assuming the calibration settings are stored in the CPU which is located in the HMI.

[Ausman]

18 hours ago, Wastle said:

I have already changed the module.

Changed for new, or tried one of the others known good?

Ensure that all the plugs, cables and sockets connecting the expansion modules are fully in place and in good condition.  Do continuity checks on all the connections from source to destination.

cheers, Aus

[Gabriel Franco]

On 2/28/2019 at 5:03 AM, Wastle said:

There are sources of electromagnetic fields, but it doesn't bother the other systems.  I have already changed the module.

Out of interest(newbie here) I am assuming the calibration settings are stored in the CPU which is located in the HMI.

Calibration data keeps on IO-LCx module.