Hi,

I'm creating an internal standard for fault reporting with S7-1200/1500 motion TOs.  Querying and displaying faults is hierarchical in this order:

1. Communication / drive faults, e.g. F07016 Drive Motor temperature
2. technology object faults, e.g. Fault 531 (HW limit switch)
3. motion control instruction faults, e.g. 16#800D Job not allowed in current state

This is organized by axis, although with Item #3, some care will need to be taken with instructions involving multiple axes.  Only faults are covered at this stage; not warnings.

Questions for you experts ....

A) To differentiate between #1 and #2, is it sufficient to check that <TO>.ErrorDetail.Number = 421?  If not, what is a more appropriate way to determine whether a drive fault is present?  For axes with analogue/digital IO interfaces, is alarm 421 triggered by the TO's fault input, if configured?

B) I am thinking for item #1, of reporting one drive fault at a time, for example by querying r2131 (as part of the telegram/extension or asynchronously).  In your experience, is r2131 generally a good enough indication of what's going on, or is the entire "fault avalanche" required to make sense of what happened?  I ask because mostly I just get a generic "drive fault" alarm on the HMI and I have to go online in Starter/Startdrive to find faults anyway.