Serial Redundancy using CP441-2?

Dear Experts,

I would like to ask your opinion regarding the solution I am thinking with one of my requirements:

Generally, I need to provide a REDUNDANT modbus connection for a yokogawa module. The modbus module I'm planning to select is CP441-2 and install it on a Siemens H system already up and running.

Please see attached document for reference.

I am not sure with this one, will this work? are there other solutions?

Thank you.

You can do it over Modbus TCP (ethernet), not over Modbus RTU (serial):
How do you establish a redundant MODBUS/TCP communication over the integrated PROFINET interface of a CPU 41x-H in STEP 7 V5.5?

If the Y okogawa has got 2 serial ports, and can request data from 2 slaves that have the same address (because the H system runs duplicate software), I'd say this is doable.

Kalle