Control Logix and Siemens S7400 PLC : Basic Maintanence Manual

Dear all,

I'm basically into DCS. As a part of my job I need to maintain few AB controllogix PLCs and Siemens S7400 PLCs. As if now, I'm looking for a maintenance manual for these PLCs where can I find information on how to identify any system faults (using Rslogix / STEP 7) and diagnose them.

Can someone share any websites / links where I can download the same.

regards,
tom

Contrologix Manuals here

Maybe something here on Logix5000 diagnostics

Siemens S7-400 here

Siemens Step7 here