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Section 61181300L1-5C, Issue 3
61181300L1-5C
Release the card retention lever and carefully seat
the card into the backplane connector by firmly
pressing on the QFO-C front panel. Verify the
fiber cables move freely between the cable guides
and the shelf.
When installed and powered, the PWR LED (green)
on the front panel lights steady.
Options
The QFO-C is software configurable through the
System Controller Unit (SCU). A comprehensive
guide to all options and configuration information is
in the menu sections of this practice.
3. OPERATION
The QFO-C transports up to four T1 signals from the
near (CO/CEV) end to the far Remote Terminal (RT)
end via a single mode fiber pair (transmit/receive) that
has an optical budget up to 22 dB. The functions of
the card are set up through the Total Access SCU via a
VT100 type terminal or via the FCD on the SCU front
panel.
The DSX T1 signals are terminated in transformers
reflecting a 100 ohm termination. The signal from a
DSX channel is monitored for BPV errors and loss of
signal. Signals up to -9 dBm may be recovered from
the incoming DSX signal. The T1 signal may be
manually looped back by a VT100 command. Up to
four T1 signals are then multiplexed. The resulting
signal is transmitted to the far end via the laser
transmitter.
The received fiber signal is detected via the fiber
receiver and de-multiplexed into four T1 signals.
These signals are de-jittered and sent to the DSX by
the T1 line drivers. The line driver circuits provide
the appropriate pulse shape for line lengths ranging
from 0 to 655 feet.
The Fiber transceiver provides a minimum launch
power of -8 dBm (optical) and a minimum receive
sensitivity of -30 dBm. This supports a minimum
optical budget of 22 dB over a single mode 1310 nm
fiber optic cable.
Connectors are single or duplex SC type. The
receiver input level is -3 dBm maximum so the
transmitter may be connected to the receiver without
overdriving the receiver input. Optical coding is ANSI
X3T9.5.
The Fiber transmitter is constantly monitored for “end
of life.” If this condition is detected, a minor alarm is
generated. In a protected system, service is switched
to the auxiliary card and a minor alarm is generated.
The QFO-C has a single dip switch (S2), which must
be set before installing the card in the Total Access
chassis. If the card is used in a non-protected mode or
is the main card in a protected mode, set S2-2 to
Working “on” (towards the top to the card). If the
card is used as the auxiliary fiber card in a protected
operation mode, set S2-2 to “off” (toward the center
of the card). The switch is set in the Working when
received from the factory.
QFO-C Front Panel Indicators
The QFO-C front panel LEDs give status
information about the card and are described in
Figure 3. Fiber Optic Receiver Cabling
Fiber Optic Transceiver
U8
XMT
RCV
S2
Working
Protect
ON
S2-1 S2-2
NOTE: S2-2 set to off = Protect
