Control logix module compatability?

I have a problem with a output card in a controllogix chasis, and need some advice from the experts. One of the outputs on the card is damaged and does not work anymore. There was a spare card of the same type (1756-OB16E) available in the stores. When this was inserted into the rack the green "OK" indicator just continues to flash. According to the instruction booklet this means: the processor is not on run mode, the module is inhibited, or is not comunicating (this is a remote rack on controlnet network). How do I get the module working? When I have had to replace modules before they have always worked straight away. I did notice that the firmware revision of the new replacement is "2.5" and the old one that was removed is "3.5". Is this the problem? I tried to use the control flash program to upgrade the firmware but my module is not in the list to permit me to upgrade. Have just searched the rockwell site and it lists that the module will work in chasis 1756-A4, 1756-A7, 1756-A10, 1756-A13, 1756-A17. Not sure what my chasis is until tomorrow.

try going into the module and disable keying. You probably have it setup as exact match so it is looking for the exact firmware as what was originally installed. I think this is your issue.

It is most likely a revision issue and those modules cannot be flashed to a new major revision.

In the RSLogix5000 project when the programmer added the module to the I/O configuration they most likely set the major revision to "3" and the minor revision to some number like "1". Then the electronic keying setting is most likely set to "Compatible Module". This means (for my example) that the module must be at least revision 3.1. A higher revision would be compatible, but an older revision would not. It could also be set to "Exact Match" where the revision listed there must match the hardware.

You could potentially get around this temporarily be changing the keying setting to "Disable".

Ideally you would get the right revision module installed and then change that setting back. Or go offline and delete the module and add the correct revision module and then download to the controller.

Disabling the keying is something you have to be real careful about though as there can actually be different tags for a rev 3 module versus a rev 2 module. If your program used those tags, they would fail to update which could potentially be dangerous.

If the module had been set to "Exact Match" then you will need to get a rev 3 module and then flash it to the specific version. Disabling keying there is not a good idea as there can be regulatory requirements in some industries behind changing that setting.

So go check that setting in RSLogix 5000 and report back to us how the revision and electronic keying settings are set.

OG

Ok thanks for that. I thought it may be something simple but didn't have a laptop avalable with the program loaded. Will chech the keying in the morning. Thanks again for your fast reply.