VIN voltage drops

1 year ago in Expansion modules / XC4x • updated by 3 weeks ago • 2

Hello,

I have an odd issue, maybe power or ground reference related.

XC43 IQAN 6.08, sensors powered using the main 24VDC not regulated VREF.

When I start driving valves with the module the reported voltage from my VIN sensors drops by up to 5%.

It happens to all of them irrespective of the sensor type.

It also jumps around a ton.

This makes a huge difference on my 0-5800 0.5-4.5V sensors.

200+ PSI, not good for sensor accuracy.

Any ideas of what to try to fix?

Regards,

Vote

Getting the same exact error on my MC43. Havent found a fix yet

It sounds as if there may be a difference in ground level between the sensor and the XC43.

With 5V sensors supplied by +VREF and -VREF, you normally avoid such problems.

For this case with a 24V supplied sensor, a consider using -VREF for sensor ground.

Just make sure the external sensor + supply has a small enough fuse to not burn the -VREF traces in case there is a short across the sensor.