Operation
Controls and Indicators
3-4
SpectraComm 553 Fractional T1 DSU
076R155-000
Installation and Operation Manual
Issue 7
Figure 3-3
Front Panel Connectors
553
OOF NS
INS
ON
L
I
N
E
I
N
O
U
T
RSP
SD
RD
EQ
BPV
AIS
TM
ALM
CH
T1
RL
TX
RX
M
O
N
LINE/IN OUT (Network Signal Input (IN) and
Output (OUT) Jacks - Insert test cables to
connect test equipment that supplies signals
to the network through the IN jack and receives
the signals back through the OUT jack for
error checking.
Connection of test equipment breaks the
normal transmit and receive signal paths.
MON/TX RX (Network Transmit (TX) and
Receive (RX) Signal Monitor Jacks) - Insert
test cables to monitor the payload portion of
TX (DSU-to-network) and RX (network-to-DSU)
signals. Monitoring does not break the normal
TX and RX signal paths.
T1/FT1
Network
SC553
DSU
Line
Out
Line
In
Receive
Send
Monitor
RX
Monitor
TX
DTE
Receive
Send
Channel Port