AB 1769-OF8V Fault

Hi Guys,

I have a fault with a 1769-OF8V that has been in service now for over two years. The data is going to the outputs on the module when I'm monitoring live from the plc but there is no change in voltage output and no active fault alarms on the plc. When I do a power reset on the system the outputs start to work again for a few days. The outputs are driving the analogue inputs for speed control on WEG CFW700 VSD's.

Has anyone had this issue before? I'm inclined to say the module is faulty and needs replaced but without a complete failure of the component it's a difficult one to call. I can't understand how a power reset gets the module up and running again if it was faulty. Surely this would imply a software issue.

Anyone any ideas?

If you have another O8FV module in the rack, simply remove the terminal blocks and swap the modules out, or if you have another card you can test it with, that would be the *fastest* way to tell if it is a software or hardware issue. If the card is fine and the data is being transferred to the output IO, I would not be inclined to call this a software issue, and would attempt to verify the hardware first

Swap card if possible
Swap terminal block
Also try reseating the card, as you could have a bad connection somewhere

thanks Sparkie for replying, those are my thoughts too.

I just got a call from the customer to say the analogue card has quit outputting completely and a power reset is no longer solving the problem.

I don't have a spare card to swap out with and it's a 7-10 day lead time to get it. I'll go ahead and order the card anyway as the installation has been inspected and no fault found.