Information Technology Reference
In-Depth Information
Other set-ups (especially on newer equipment) allow access to the batteries status. An exam-
ple query is
Address Function LRC
:12 07 E7
and an example response is
Address Function Flag data LRC
:12 07 7D 6A
18.2.8 Fetch Communications event counter (11, 0Bh)
This function returns a status word and an event count for the slave's communications event
counter. An example query is
Address Function LRC
:12 0B E3
and an example response is
Address Function Status (hi) Status (lo) Event count (hi) Event count (lo) LRC
:12 0B FF FF 02 08
DB
A status of FFFFh indicates that the slave is still progressing a program function, else it will
be 0000h. The event counter holds the number of events that have been counted by the con-
troller.
18.2.9 Fetch communication event log (12, 0Ch)
This function returns a status word, event count, message count, and a field of event bytes
from the slave. The status word and event count are identical to that returned by the fetch
communications event counter function, but it is followed by a 16-bit value which defines
the number of events stored. The events are then listed after this.
18.3 Modbus diagnostics
The 08 function is used to get slave diagnostics. This is used with a number of subfunctions.
The format, and example, of a diagnostics function are
Address Function Subfunction (hi) Subfunction (lo) Data (hi) Data (lo) LRC
:12 08 00 FF 02 08 DB
The subfunctions are given in the following table.
