CompactLogix L24 Embedded IO Issue

Hi all,

I am starting to set up a test bench. I salvaged an old L24-QBFC1B and updated the firmware to v30 so I could run a "Test Bench" program with my version of Studio. I plan to set up multiple expansion IO modules on top of the already embedded IO on the module in the future.

I've put power to the controller and flashed the firmware appropriately. However, the embedded IO is not responding. I don't have anything connected to this controller other than the power and have created a generic L24 program that only has the embedded IO set up in the tree.

I wanted to test some of the inputs and outputs with push buttons and a small stack light, but I can't get the controller to recognize any of its embedded IO. I thought perhaps you needed a separate power supply to power the embedded IO so I tried doing that with a AB supply with no luck.

Any ideas on what I can do? Perhaps this is the reason why I found the controller in the "do not use" pile

The module fault I"m getting says 16#0312 invalid link address. How can this be with embedded IO?

Thanks for your help in advance!

This might be trivial but the error you are experiencing is usually caused by a missing or improperly attached 'End Cap' and/or lose/unlocked/bent pins IO connectors.

Hopefully this is the case...Otherwise the junk pile truly is what it claims to be......

dmargineau said:

This might be trivial but the error you are experiencing is usually caused by a missing or improperly attached 'End Cap' and/or lose/unlocked/bent pins IO connectors.

Hopefully this is the case...Otherwise the junk pile truly is what it claims to be......

Click to expand...

By 'End Cap', are you referring to the removable terminal blocks that connect to the various IO pins? If so, I just tried disconnecting/reconnecting them. I felt all of the pins for looseness and, while some did feel slightly loose, it didn't seem to be to the level of loose baby tooth. Thanks for your help!

I am referring to the 1769-ECR Right End Cap Terminator to be used with the 5730 L2 and L3 Expandable IO Controllers.

See pic...

Ahh I didn't know that had to be there. Will get one on and let you know. Thanks!

Good catch, dmargineau !

The embedded I/O in the 1769-L2x family is actually just the same electronics as the actual 1769-series expansion I/O, built into the same enclosure.

So the 1769 bus does require an End Cap. The magic is in that little PC board with the resistors and capacitors that connects to the connector and terminates and balances the data bus.

Update 6/20: The End Cap Terminator worked! Thanks dmargineau!

Sooo...They took the End Cap off, used it somewhere else then labeled the cannibalized controller "Do Not Use!"...Nice...

That appears to be the case! So I apparently have stumbled upon a diamond in the rough, and all it took to revive it was a $40 part! Thanks again

Yep...It is some $2800.00 new...You're very welcome!...