Details
-
Task
-
Resolution: Unresolved
-
P3: Somewhat important
-
None
-
None
-
None
Description
On the matter of whether someone needs the diagnostic message counters which according to the spec should be serial line only, some research for current automation products has the following result:
Diagnostics (fc 08) subfunction 21 is in use for get/clear Modbus Plus statistics for modbus plus networks, but is on some modules used for get/clear ethernet statistics. In addition, subfunction 22 is used by other devices of Schneider:
page 137.and following lists a subset of the counters also used already in QModbusServer. Even if we don't implement this subfunction as it is not part of the standard, the number of messages send/received, exception responses etc. are used on ethernet diagnostics as well, so I propose we leave the current counters all in QModbusServer for re-use with get functions if anyone wants to construct a diagnostics subfunction implementation that requires the current counter values.