AB comms to VFD on another AB network

Hello. I am working on a project with multiple AB L72 PLCs, each with EN2T cards to connect over Ethernet.

There is a VFD which has been connected to a particular PLC's EN2T (PLC 1) but it is actually to be controlled by a different PLC (PLC 2) - I am not sure why this topology was selected.
I was hoping for some advice as to the best way of communicating between the PLC and the VFD.

On the PLC 2 side:
I have nested PLC 1 underneath one of PLC 2's EN2Ts, and have visibility, but unfortunately I cannot nest the VFD underneath PLC 2.

We are using MSG to send other bits of data required between systems, but the VFD has a lot more data to be transmitted so I was hoping there might be a cleaner way to do this.

Also, my networking knowledge is not amazing, so this may be letting me down here. Apologies if any of this is unclear!

Any advice appreciated, thanks.

Change the wiring or network configuration to allow the 1756-EN2T in the chassis with the ControlLogix that needs to control that drive to communicate directly with the drive.

You can't have more than one 1756 network module between a CPU and an I/O device. You simply can't. It's been that way for 20 years, first on ControlNet then on EtherNet/IP.

OK: CPU -> Root Bridge Module -> Network -> I/O Device.

Not OK: CPU -> Root Bridge Module -> Network -> Backplane -> Bridge Module -> Network -> I/O Device

In some older systems an intermediate network link will work for a while until the buffers get overloaded, and the software won't warn you about the configuration problem. In modern Logix the software should prevent you from creating such an invalid configuration.

You can send MSG instructions across multiple "hops" of a variety of CIP networks, but not I/O connections.

Thank you Ken.

I figured it was not possible alright, just said I would double-check.

I'm not sure it is feasible to have the motor moved, but will see what can be done.