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MODEM
V.24
MAINTENANCE
TERMINAL
1
2B+D,( B=64kbps, user channel.
2
SOPHO-LAM P375 release 3 in DTE mode (!)
3
Special cable (See appendix C)
4
Modulated carrier.
Figure 3-8 Maintenance Terminal connection for changing SOPHO-LAM settings (Switched
Line).
Of course the SOPHO-LAM settings can also be changed by using the keypad of the SOPHO-
LAM or by downloading the SOPHO-LAM.
To change the modem settings, the maintenance engineer has to dial the convertor DNR.
After dialling this DNR the connection is made between the maintenance terminal and the
convertor. When the modem supports Hayes commands, the modem settings can be changed
using Hayes commands.
Call progress is as follows:
• Outgoing callSOPHO-LAM
When the calling party dials the convertor group DNR (pool for outgoing calls), one of the
convertors is selected and the calling party is connected to a convertor modem via the
SOPHO-LAM. Then the calling party has to specify the destination DNR. Depending on
the modem, Hayes commands and/or V.25bis commands can be used. For example the
DTE dials ATD<destination DNR>. The convertor modem now sets up the connection
via the ALC.
• Incoming call
The calling party dials the convertor group DNR (pool for incoming calls). This is the group
DNR of the ALC circuits to which the convertors are connected. Then the calling party is
switched through to the analogue side of a convertor modem. When the convertor
modem is idle and operates in the automatic answering mode, it detects the incoming call
and establishes the connection with the remote modem (automatic answering). Now the
40
SN
IMP
4
64 kbps
ALC
1
IMP
64 kbps
2B+D
DLC/
SOPHO-
DTX
MODEM
IMP
4
64 kbps
ALC
2
3
V.24
LAM
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