STAT-4, STAT-8, AND STAT-24
42
Table 4-1. Stat-8 controls, indicators and connectors.
Item
Control, Indicator, or Connector
Function
1
PWR indicator
Lights when the STM is powered.
2
SYNC indicator
Indicates stat mux synchronization status
Condition
Indication
Off
Stat mux not powered.
On
Stat mux powered and
synchronized with the remote.
Flashing
Stat mux powered, but not
(Continuous)
synchronized with the remote.
Flashing
Stat mux retransmits data frame
(Intermittent)
upon request of remote stat
mux (usually because a noisy
line causes errors in the data
received by the remote stat
mux).
3
ERR indicator
Lights when a hardware malfunction was detected during
the self-test automatically performed upon power-up,
or after pressing the RESET button
4
OVF indicator
Lights when STM buffers are full. In a properly designed
system, this condition usually indicates that one of the
DTE units connected to the stat mux does not respond
to configured flow-control commands
5
TEST indicator
Lights to indicate that the stat mux is in the diagnostics
mode (one of the test loops active) or in the command
mode. In either case, traffic is interrupted
6
Sub-channel activity
Indicators, one for each sub-channel, light when
indicators
corresponding sub-channel is active (receives or
transmits data)
7
Main (composite) channel
Light when the main channel is active (receives or
activity indicator
transmits data)
8
Reset button
Resets stat mux internal circuits (including the data
buffers) and initiates the power-up self-test
9
Sub-channel connectors
Connections to stat mux sub-channels (one for each
sub-channel)
10
Power connector
AC power connector with integral fuse