1771-OAD and 1771-OAD C

Hi Folks....I ran across an interesting problem today and wondered if anyone else has seen this before. About a week or so ago we had an output go bad on a 1771-OAD output card, all we have in stock are 1771-OAD revC cards. So I put one in place and everything is cool, or so I thought. Today a solinoid valve connected to the same card would not work unless you pulled the swing arm out and back in again. So I pulled the card next to it which was a 1771-OAD and put it in that position and vice versa. I then noticed that the 1771-OAD revC in the other slot would not drive any solinoid vales connected to it. It seemed to work with any other device but a solinoid valve. I went out to the "bone yard" and found a 1771-OAD, put it in and everythings right with the world. I searched the AB knowledge base but came up empty.
Any theorys or ideas?


Thanks and later...Todd

The difference between OAD and OAD C you see on the picture is the front connector.
"C" you see stands for a wiring arm that was shipped from the factory with this card. No differenece between here.
But difference may be between series of the card - different series, different hardware.
In any case - do not get cards from the boneyard, get a new card from A-B distributor.

Cont_conn

In any case - do not get cards from the boneyard, get a new card from A-B distributor.

Click to expand...

What I call the "boneyard" is our shop stock {Cards from different plants that have closed and we got their "bones"} So it's good stuff ,it's just not chargeable through the supply room. All our supply room stock comes from the A-B distributor.

Thanks and later...Todd