Lr4 Card - Aastra AXD Installation And Maintenance Manual

4.14.13 LR4 card

4.14.13.1Description
The LR4 card enables four analogue trunk lines to be connected.
It can also be fitted with tone detection (DTOC) or billing (FTXA or FTXC) daughter cards.
4.14.13.2Functional description
The LR4 card mainly carries out the following functions:
• Analogue line supervision, by:
- transmitting commands from the central unit to the public network:
- outgoing call request
- line off hook and release
- pulse dialling
- detection and transmission of actions initiated on the public network to the central
processing unit:
- detection of line off hook on the public network side
- detection of the public network response to a line off hook on the iPBX side
- detection of a call signal from the public network
- detection of the line busy tone: this function is ensured by a daughter card
(DTOC card); a DTOC card can be associated with each line.
The release signal (polarity inversion) must be sent by the public exchange; the
signal is detected by the LR4 card.
If the public network does not send this signal, the LR4 card must be fitted with
DTOC cards, with one card per line.
- billing pulse detection: this function is ensured by a daughter card (FTXA card for
50 kHz pulses, FTXC for pulses from 12 to 16 kHz); a billing card can be
associated with each line.
• Voice transmission and conversion:
- in digital form, from the UCV card to the analogue sets
4 PCM TSs are exchanged with the UCV card, each being the medium for voice
carried over an analogue line
- in analogue form, from the analogue sets to the UCV card.
• Power supply: the card receives several supply voltages on the backplane connector
(J1):
- +5 V, -5 V used for the operation of its internal circuits,
- -48 V used to supply the short analogue lines connected to PSTN equipment
requiring remote supply,
AMT/PTD/PBX/0058/4/6/EN
Page 284 01/2011
Installation and Maintenance Manual - Aastra 5000
Description des sous-ensembles