51
MINIATURE 2-CHANNEL STATISTICAL MULTIPLEXOR
performed satisfactorily on the local sub-channel loop, usually indicates a problem
in the remote Multiplexor.
6.2.3 M
ODEM
L
OOPS
(1) Analog modem loop
When the analog modem loop is connected, the composite channel data
transmitted by the local Multiplexor is returned to the receive line of the local
Multiplexor after passing through the local modem, and the communication link
is disconnected. All the data arriving from the remote Multiplexor while this loop
is connected is lost.
This loop tests the complete local Multiplexor, its composite-channel
connection cable, and the local modem.
As long as the loop is connected, the SYNC indicator of the local Multiplexor
must light continuously; failure to do so, after the local Multiplexor performed
satisfactorily on the local composite-channel loop, indicates a problem in the
composite-channel connection cable and/or in the local modem.
(2) Remote digital modem loop
When the remote digital modem loop is connected, the composite channel data
transmitted by the local Multiplexor is returned. from the remote modem, after
passing through the communication link and the local modem, to the receive line
of the local Multiplexor. Any data transmitted from the remote Multiplexor is lost
during loop connection.
This loop tests the complete transmission path, including the local Multiplexor,
its composite-channel connection cable, the communication link, and the local
and remote modems.
As long as the loop is connected, the SYNC indicator of the local Multiplexor
must light continuously. Failure to do so, after satisfactory performance in the
analog modem loop, usually indicates a problem in the communication channel
and/or in the remote modem.
