STAT-4, STAT-8, AND STAT-24
44
4.2 Operating Instructions
4.2.1 G
ENERAL
After preparing for operation as explained in
Sections 3.3
through
3.6
, the stat mux normally operates
unattended. Operator intervention is only required when the stat mux is set up for the first time or must be
adapted to new operational requirements. The stat mux configuration is stored in a non-volatile memory and is
not affected when power is turned off.
4.2.2 P
OWERING ON THE
S
TAT
M
UX
Connect the power cable to the stat mux rear power connector, then set the power switch to ON. The PWR
indicator should light.
Check that after a few seconds (during which the stat mux runs a self-test), the ERR indicator goes out.
If the link to the far stat mux is not yet operational, the SYNC indicator will flash. Wait until the link becomes
operational, and check that the SYNC indicator stops flashing and lights continuously.
4.2.3 N
ORMAL
O
PERATION
During normal operation, the PWR (when present), SYNC, and MAIN indicators should light continuously, and
the TEST and ERR indicators must remain off. Sub-channel activity indicators flash according to the traffic load
and go out when the sub-channel is idle. When the TEST indicator lights, traffic is interrupted, even if all other
indications are normal. On noisy links, the SYNC indicator may flash from time to time: this indicates automatic
retransmission of a data frame. Automatic retransmission occurs when the remote stat mux requests it, when
errors are detected in the received data, and it ensures that only valid data is transmitted.
4.2.4 P
OWERING
O
FF THE
S
TAT
M
UX
To turn the stat mux off, set the power switch to off.
4.3 What To Do in Case of Malfunction
Here is a list of actions that will help you return to normal operation in case a problem occurs. Additional
information on stat mux diagnostics appears in
Chapter 5
.
4.3.1 P
RELIMINARY
C
HECKS
1. Check that the stat mux is powered (when powered, the PWR indicator lights).
2. Check that cables are properly connected.
3. Check that the equipment connected to the stat mux is powered and operates normally.
4.3.2 C
HECK
S
TAT
M
UX
I
NDICATIONS
Check the configuration of local and remote stat mux and make sure it corresponds to the requirements of the
equipment connected to its sub-channels.
