STAT-4, STAT-8, AND STAT-24
48
5.2.3 M
ODEM
L
OOPS
1.
Analog modem loop.
When the analog modem loop is connected, the composite channel data transmitted by
the local stat mux is returned to the receive line of the local stat mux after passing through the local
modem, and the communication link is disconnected. All the data arriving from the remote stat mux
while this loop is connected is lost.
This loop tests the complete local stat mux, its composite channel connection cable, and the local modem.
As long as the loop is connected, the MAIN and SYNC indicators of the local stat mux must light
continuously; failure to do so, after the local stat mux performed satisfactory 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 stat mux is returned from the remote modem (after passing through the
communication link and the local modem) to the receive line of the local stat mux. Any data transmitted
from the remote stat mux is lost during loop connection.
This loop tests the complete transmission path, including the local stat mux, its composite channel
connection cable, the communication link, and the local and remote modems. As long as the loop is
connected, the MAIN and SYNC indicators of the local stat mux 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.
