Logix5000 Modbus TCP AOI having "overlap" issues

Hi all,

I've been trying to get Modbus TCP to communicate (read only) with the Modbus TCP AOI that Rockwell provides, but I'm having issues and was wondering if anyone might help.

What I'm seeing is that when I try to poll holding registers (34 total), it only reads about ten of them. Sometimes I'll get an STS_Overload alarm, sometimes not but the status of the transaction always says "exception".

I've read through the documentation and have been playing with the Periodic Task's execution period, as well as the AOI's Poll Interval but nothing seems to fix it. Thanks for any help!

Can you post your ACD upload in faulted state, and wireshark?
Modbus Slave device manual would help too.

Overlap means that your peer device did not respond before next scheduled read attempt.
Since you have an exception, then you can read exception code.
I would say that you are trying to read something that device does not support.

If you can't post your full ACD, then do upload, export one AOI rung only and post that rung. Rung import will contain all configuration and exception values