2 channel/dual channel safety circuits explanation required.

Hi all

In a nutshell I am looking for a detailed explanation on 2 channel safety relays/circuits.

I have attached 2 pics of the equipment in front of me.

I would just like to see if an experts explanation lines up with my own understanding.

I would much appreciate your opinion on the channels related to the safety relay in the electrical drawings and how and in what order you would approach the fault finding.

Any replies would be helpful.

Cheers