User guide

ASCOM USER GUIDE
High Speed Base Band Modems
33
• Receive Data. Modems synchronised and far end control signals are on, local end are off.
• Send Data. Modems synchronised and local control signals are on, far end are off.
• Data Transfer. Modems are synchronised and control signals are on at both ends of link.
6.5.2 Alarms
This read only display gives modem alarm information.
• No Alarm. There are no alarms present.
• No Sync. The modem is not synchronised with the far end.
• CRC Error. An in service test is running and CRC errors have been detected.
This alarm message is displayed for 5 seconds only unless the errors persist.
• LOS / CD Fail. For G.703 only:
LOS refers to loss of sync on the copper pair side.
CD Fail refers to Carrier Detect fail on the G.703 side.
6.5.3 Line Quality
This read only display gives an indication of the signal quality on the copper pair(s). A value of
0 indicates the units are not synchronised. The line quality is high (high signal to noise ratio) if
the value is 10 and the line quality is low (low signal to noise ratio) if the value is 1.
This display also gives an indication as to the progress of any start up sequence. When the
unit is trying to synchronise it will display a series of asterisks. The sequence starts with one
asterisk, and ends with four asterisks (on each pair) indicating full synchronisation.
6.5.4 Interface Status
This read only display shows the status of the interface control lines. The control lines
displayed will depend upon the interface selected.
e.g. Circuit 105:
For the X.21bis circuits there is also a composite display showing all of the control lines on one
line of the LCD. Here each circuit is represented by its last digit and the on state is denoted by
a filled in block.
e.g. 105,106,107,108,109 ON, 140,141,142 OFF:
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32 ASCOM USER GUIDE
High Speed Base Band Modems
6.5 STATUS MENU
This menu displays alarm information to indicate the operational state of the modem.
6.5.1 Unit Status
This read only display gives an indication of the overall state of the data link.
• LTU Not Ready. The modem is not in synchronisation with the far end.
• LTU Ready. Modems are synchronised, but control signals are off at both ends of link.
Unit Status
Alarms
Line Quality
Interface Status
Note that other interface specific
messages may appear in the
alarms section
Menu Locked/
Unlocked