Product manual

12 Working with Third-party Communication Diagnostics TAC Xenta Server – Gateway, Technical Manual
104 (184) Schneider Electric Buildings AB, June 2011
04-00124-06-en
12.3 Diagnosing Incorrect Target Communications
Run the diagnostics log at the appropriate verbosity level and monitor
the resulting communications activity. If necessary, record the log to
file for later playback.
The type of log data is dependent on the target system. However, the
basic form should resemble the following log excerpts from the Modbus
Master example.
Example log: Correct Operation
Messages prefixed by REQ indicate the type of request that was sent out
to the target system (in the example, the first REQ message retrieved a
range of Modbus registers from the power meter slave device at address
1). The XVAL-prefixed messages indicate a change to an I/O value (in
the above example, the third XVAL message indicates that Plant:Volts
P1 was read from the meter as 258.305 volts). Obviously, the types and
formats of messages are dependent on the target, but should be reason-
ably self-explanatory.