OR ring N+1 Redundant Circuit

PVR said:

1)What channel should be connected to the "+" and "-" side of the differential signal, respectively?

2) For the differential mode, is every "-" side channel connected to ground?

This ideal diode is intended for DC applications for power savings, not to rectifying AC signals.

PVR said:

We are using 2 individual PFE500F-12 (AC-DC) with two different source of AC 230V to 12 V and that two 12V 42A ORing for the one N+1 redundant 12V  is the Load for system. whether LTC4357 & SQM50N04-4M1_GE3 sufficient for 12V 40 A N+1 redundant.

For high current applications, I recommend the LTC4359.
It's floating topology protects the IC from abs max violations during input short and supply switchover.

As for the FET, the SQM50N04-4M1_GE3 specs are: R_DS(ON)=4.1mΩ with Θ_JA=40C/W.
Assuming one channel carries the entire 40A, you need at least 2 FETs in parallel for reasonable temperatures.
T_J will rise 65C above ambient with 2 FETs in parallel.
The temperature of the operating environment determines how much junction temperature can rise.