CANOGA PERKINS 2262 T1/E1 Fiber Optic Modem - Manual (Page 15)

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2262 T1/E1 Fiber Optic Modem Canoga Perkins
3. Operation
During normal operation, the 2262 receives input data at the metallic interface and
modulates it into an optic signal. It also detects the optic input signals, demodu-
lates them back into the original T1 or E1 data stream, and retransmits output data
at the metallic interface.
The 2262 lights the Tx LED (see Figure 3-1) when data pulses are detected from the
Input leads, and lights the Rx LED when data pulses are transmitted at the Output
leads. When the 2262 fails to receive optic signals, the alarm relay will be
deenergized and the relay contact status will be changed.
Figure 3-1.
2262 Front Panel
3.1 Local Loopback Operation
When the 2262 Loopback Switch is set to Loc, the Loopback LED will light and the
2262 will operate in the local loopback mode. During this operation, the data
received from the Input leads will be looped directly back into the Output leads.
The Tx and Rx LEDs will be lit as data pulses are presented on those leads. The
received optical data will be demodulated then remodulated. It will then be transmit-
ted back out as transmit optical data. The relay contact status will stay normal as
long as optical pulses are presented at the optical Rx port.
3.2 Remote Loopback Operation
When the 2262 Loopback Switch is set to Rem, the Loopback LED will light and the
2262 will then operate in the remote loopback mode. During this operation, the
transmitted optical signals at the optical Tx port will be further encoded to carry a
remote loopback protocol.