Been seeing a high failure rate on these PLC's on 2 of our processes. The control power is feed through a APC UPS to a 24VDC power supply to power the unit. Getting a hard fault where the OK LED comes on red and stays red. It never sequences through all the LED on power up. Tried the hard boot by holding in the reset button and applying power. Has anyone on else seen a high failure rate on this model PLC? TIA..

 

Can you upload fault picture before you clear it?

 

Try the GSV (Get system values) function block see if can catch something over there

 

It doesn't reset..