Hello Ton, aru, prakash;

Even before you open the diagnostic buffer you must establish a list of existing problems on the PLCside, including which diagnostic LEDs are active on the CPU or the IO modules, and try to determine which are related together (first pass diagnostics of the situation).

For instrument problems, we have to know how they are connected to the PLC (hardwire 4-20 mA for example or network), if they are powered properly, and what exactly is the problem they show.

Then open the diagnostic buffer of the CPU to see if any messages look like they are related to the problems you have listed.

We can help you once you have a good description of the existing situation, and when yuou can send us the diagnostic buffer contents.

Hope this helps,

Daniel Chartier

prakash_001

Hi,

Kindly give some tips for troble shooting in site for S7 300 & 400, and for instruments also