Siemens S7-300 Bus Fault

[HarleyRay0]

Can anybody tell me if there is a way to stop my PLC going into halt when I get a bus fault?

 

[smf]

Yes, put in some OB, don't remember what OB number you need (ob86?) but you can find it in the manual.

 

[HarleyRay0]

Thanks smf.

 

[JesperMP]

As always:
When you have a fault in an S7 PLC, you must investigate the diagnostics buffer. The diagnostics buffer will tell you why the PLC has faulted, and what error OBs that was attempted to call in order to avoid the CPU going into STOP.

A tip: In stead of just mindlessly copying an empty OBxx into the program, add some alarm code to the error OB to warn the operator that something is wrong.

 

[uptown47]

I think it's OB86 for bus errors but as Jesper said it is important to try and find out why the PLC had a bus error. The diagnostic buffer will be the starting point. It could be a bad connection somewhere or a poor earth etc... ;-)

 

[HarleyRay0]

Thankyou all for your help.