I n s t a l l a t i o n & P r o g r a m m i n g M a n u a l
60
ISDN Cards
This optional card provides an interface to a basic rate ISDN exchange line. Support for 2 basic rate
lines is possible with an ISDN card fitted into expansion slot 1 and expansion slot 2. Each ISDN
card adds two exchange lines to the unit, using the two ISDN b channels on a basic rate ISDN
connection. Two analogue extensions are also added with each ISDN card. An ISDN card in
expansion slot 1 will add exchange lines 3 and 4 plus extensions 21 and 22. An ISDN card in the
second expansion slot will give exchange lines 5 and 6 plus extensions 23 and 24.
Socket & connector supplied with ISDN card
to pin 5 (green)
to pin 4 (red)
to pin 3 (black)
to pin 6 (yellow)
ISDN connector
Rx+
Rx-
Tx+
Tx-
pin 1
pin 8
Figure 4-7 ISDN RJ 45 Socket wiring
A connector is supplied with the ISDN card, wired as shown in Figure 4-7 above. When the system
is powered up the ISDN card is automatically detected and the system runs a test to verify that the 1
st
and 2
nd
S bus, if connected, are operational. If either S bus is not connected or temporarily down
then the tests will be repeated at 5 minute intervals until the B channels are available, during this time
attempts to seize an external line routed over an ISDN exchange line will be blocked with busy tone.
The system may be connected in parallel with other ISDN devices with a line in point to multipoint
configuration. If a B channel is busy on another ISDN device connected to the ISDN line then the
system will show the line as busy and stop calls being routed out on that line.
The ISDN card will generally function directly without programming, though to take advantage of
the extra services offered by ISDN some programming is recommended. Programming details are
found in the ISDN Programming section on page 43. Use of the PC program with V24 option card
is recommended to simplify the process.
If you wish outgoing calls to be made on the ISDN network in preference to any PSTN lines then
program the feature ‘ISDN first’. The code to be entered at extension 13 is *8 201 #.
The end of line 100
Ω
terminating resistors must be fitted to the last device connected to the ISDN
S
0
bus. This also applies if the device is the only equipment connected, or if it is the only device
connected. The ISDN card contains two links, J1 and J2 which will put the termination in place if
fitted.
Music on Hold Source
The telephone system provides a standard audio 3.5mm socket for an external music source, located
next to the V24 port. The music source should be 600
Ω
, 0 dBm / 775mV max, as found at the ‘line-
out’ connectors of many items of audio equipment. It is important to take anti-static precautions and
discharge any static build-up on your person before connecting this music source. It is recommended
that the telephone system be powered down for this operation. Note that the external music on hold
has to be activated before it is enabled, see page 45 for details.
Battery Back-up Unit
The telephone system is powered by an integral 220-240 V AC power supply. During mains failure
the analogue exchange lines 1, 2, 3 and 5 are connected directly to extensions 11, 12, 21 and 23
respectively, providing a direct telephone to exchange link, no telephone system services or ISDN
exchange line operation will be possible. The optional battery back up unit will power the system in
the event of a mains failure and it will operate as normal until the internal batteries are exhausted.
Important!
