|
General The LL304E/T is a 4-channel telephone line extender on fibre system. The LL304E is the Exchange side unit that interfaces directly to incoming telephone lines, or to a PABX, and resembles the standard telephone instrument characteristics. The LL304T is the Telephone side unit that interfaces directly to telephone instruments and resembles the standard exchange characteristics. Basic System Description The LL304E acts as the Master unit that generates the system clock, and the LL304T acts as a Slave unit that locks onto the Master unit. The LL304E unit digitises the four telephone lines and multiplexes them into a single high-speed data stream, which is then converted into an optical signal for transmission across optical fibre. The LL304T unit converts the optical signal received from the fibre into a high-speed data stream, which is then demultiplexed and converted into the four separate analogue telephone lines again. The same process happens in the opposite direction.
The LL304E units are available in two options. The first is a standalone desktop unit in a small metal enclosure that is compact enough so that two units can fit side by side in a 19? rack, with a height of 2U. The second is a rack mount card that can plug directly into an OS800 3U 19? sub rack assembly. The LL304T can only be supplied as a standalone desktop unit.
The unit is modular in design and can thus be upgraded easily with different power supplies or optic options. The power supply options available are 220Vac, 110Vac, 110Vdc, 48Vdc and 12Vdc. The optic options cover distances of 3.5 & 12km on multimode, and up to 40 or 80km on singlemode.
Features - Sends four analogue telephone lines across a single fibre pair
- Noise and EMI immunity as compared to long copper cable runs
- Modular design allows quick & easy changing of power supplies and optic options
|
