Specifications

3U Traffic Outstation Handbook
667/HB/26568/000 Page 177 Issue 15
11.7.3 Modem Control Indicators (MCI)
This command displays the state of the modem interface (some indications are for
hardware functions, others will be software). The default display is binary with a “1”
indicating the signal is active.
FORMAT: MCI <n>
where <n> is the ‘minor index’.
First Byte (i.e. Minor index = 0):
BIT No.
SIGNAL NAME STATE REPRESENTED
0 CLEAR TO SEND Not used.
1 REQUEST TO SEND Not used.
2 CARRIER DETECT Instation carrier present.
3 DATA SET READY Link established with the Instation modem
4 CALLING/ANSWERING Call/answer sequence in progress (0 =
calling & 1 = answering).
5 Not used
6 CALL REQUEST Auto-call by OMCU (not set if retry delay
is preventing the OMCU from dialling out)
7 CALLING INDICATE Answer to ringing tone required
Second Byte (i.e. Minor index = 1):
BIT No.
SIGNAL NAME STATE REPRESENTED
0 CALL INTERRUPTED Not used.
1 DATA LINE OCCUPIED Call or answer in progress.
2 DATA TERMINAL READY Ready to call or answer.
3 – 7 Unused.
11.7.4 Message Diagnostic Data (MDC)
During any Instation - Outstation (OMCU) communication all characters and
messages are checked for errors. This log stores these together with a total count of
all good characters received.
Again as in previous logs two sets are stored one for current data (miner index = 0)
and one for historic data (minor index = 1)
As each condition occurs the relevant count is incremented and when the number of
characters received reaches its maximum value (FFFFH) then all counts are copied
to the ‘historic log’ (minor index = 1) and then reset to zero. If any count reaches its
maximum value whilst the character count is below its maximum limit then the value
‘locks’ at FFFFH.
Note: All count information is displayed in HEX.