58
MINISTAT-FOUR
This loop tests the complete transmission path, including the local MiniStat-Four
and the communication link.
As long as the loop is connected, the SYNC indicator of the local MiniStat-Four
must light continuously; failure to do so, after the local MiniStat-Four performed
satisfactorily on the local composite channel loop, indicates a problem in the
communication link. For example, intermittent flashing of the SYNC indicator
indicates a high error rate on the link.
Sub-channel activity indicators light according to traffic; a flashing ERR indicator
means that the MiniStat-Four buffers are full because of flow-control problems
stemming from the equipment connected to one of the local sub-channels.
Remote sub-channel loop
When a remote sub-channel loop is connected, the local transmit data is
transmitted to the remote MiniStat-Four. It’s returned to the local MiniStat-Four
sub-channel instead of the transmit data connected to the remote MiniStat-Four
sub-channel. All the data arriving from the remote MiniStat-Four sub-channel
while this loop is connected is lost.
As long as the loop is connected, the sub-channel activity indicator lights according
to traffic. The equipment connected to the sub-channel must receive its own
transmit data without errors. Failure to do so, after the local MiniStat-Four
performed satisfactorily on the local sub-channel loop, usually indicates a problem
in the remote MiniStat-Four.
6.2.3 M
ODEM
L
OOPS
Analog modem loop
When the analog modem loop is connected, the composite channel data
transmitted by the local MiniStat-Four is returned to the receive line of
the local MiniStat-Four after passing through the local modem, and the
communication link is disconnected. All the data arriving from the remote
MiniStat-Four while this loop is connected is lost.
This loop tests the complete local MiniStat-Four, its composite-channel connection
cable, and the local modem.
As long as the loop is connected, the SYNC indicator of the local MiniStat-Four
must light continuously; failure to do so, after the local MiniStat-Four performed
satisfactorily on the local composite channel loop, indicates a problem in the
composite-channel connection cable and/or in the local modem.
