Looking for Standards to Reference. ICS, ICS Security, O.T. Vs. I.T. Standards.

I'm looking for standards regarding IACS, ICS Security, O.T. Vs I.T. Network Design to create a Powerpoint Presentation, If you know any off the top of your head.

Our Customers I.T. team has no idea about IACS and O.T. networks and how they are designed differently. Think some FLEX & VFD's on two Device level Rings is going to be like some enterprise Cisco switches on a ring or something.

My goto is the CPwE documents from Rockwell, but I was looking for more standards from ISA, ISO, IEEE, NIST...

Thanks for the help!

like this but, maybe not entirely security focused.
NIST SP 800-82 Rev. 2

800-82 is security focused but still one of the best resource fo IT/OT design.

ISA 95 is another https://en.wikipedia.org/wiki/ANSI/ISA-95

"FLEX & VFD's on two Device level Rings is going to be like some enterprise Cisco switches"

I hope you skipped a level or two in that.

Yet another resource is ICS-Cert's training site. You can search for it.

You can also watch this presentation but be sure to give credit for it.

https://www.youtube.com/watch?v=E_MXyQYt3-g