Specifications

Chapter 1 - Introduction FLM-1 Installation & Operation Manual
1-4 Functional Description 16/01/01 11:12 AM
Front Panel
The front panel provides control over the operation of the unit. The LEDs
provide real-time indications related to the operation and status of the unit.
Two push-button switches allow test loopbacks for the FLM-1 diagnostics.
For details, see Chapter 3, “Operation” and Chapter 4, “Troubleshooting
and Diagnostics”.
Rear Panel
The rear panel of the unit allows access to interface and power
connections. For details, see Chapter 2, “Installation”.
1.3
Functional Description
FLM-1 can operate in two operation modes: set to 6 or 12 channels, which
is controlled by a user-selectable strap. When the unit is set for six channels,
each channel can be used to transmit full duplex data end-to-end. When
the unit is set for twelve channels, each subchannel can be used for either
data or control signal transmission, according to the specific application. For
example:
•
All twelve channels can be used to transmit full duplex data end-to-end.
Note
In the case of DB-25 connectors version, this mode requires a channel
doubler cable (see Section 2.4 for details).
•
Six channels can be used to transmit full duplex data and six can be used
to transmit control signals end-to-end.
Note
This operation mode requires a channel doubler of another type. This channel
double would be different for different types of subchannel connectors
(DB-25 or RJ-45) and different types of control signal. For more information
see Connecting the Interface in Section 2-5.
Multiplexing is implemented by using an over-sampling technique. Each of
the twelve channels is sampled at 78.6 kbps for the electrical (4-wire) option
or at 157.2 kbps for the optical (fiber) option.
Table 1-2 summarizes the FLM-1 performance with various options and
modes of operation.
Table 1-2 Performance in Various Modes of Operation
No. of Max Distortion (%)
Subchannels
in Use
Data Rate
(kbps)
4 Wire Fiber
6 19.2 12.5 6.25
6 38.4 - 12.5
12 19.2 25.0 12.5
12 38.4 - 25.0