Installing a New System
Connecting to the MDF - Page 17
Installation & Maintenance
Installing a New System - Page 17
INDeX 30
38DHB0002UKDF- Issue 4 (07/2001)
Basic Rate ISDN Cabling
Basic Rate ISDN S-interfaces can support single
(point-to-point)
or multiple
(point-
to-multipoint)
ISDN terminal devices. The number of devices supported depends on
the cable distances and type of wiring used.
Basic Rate ISDN T-interfaces only support single
(point-to-point)
connections.
Wiring Notes :
– The table below gives the maximum cable distances for 0.5 mm diameter
CW1308 wiring. Figures in brackets refer to 0.5 mm diameter CW1700 wiring.
Point-to-Point
Short Bus
Extended Bus
Maximum Bus Length
400m (800m)
100m (150m)
250m (400m)
1st Socket to Last Socket
N/A
–
45m (70m)
Maximum No. of Sockets
1
8
4
CAT5 cabling can also be used for cable lengths of up to 800m.
– In all configurations, the first and last sockets must include 100
Ω
±
5% resistors
across the both transmit pair and across the receive pair.
– If a socket is added as a spur rather than a bus junction, the spur length must
not exceed 1m.
– All wiring must be twisted pair or quad type.
Point-to-Point Connection :
– Single ISDN Terminal Device Socket.
Point-to-Multipoint Connection :
– It is vital that wiring polarity is maintained throughout the wiring bus.
Notes:
1. In the MDF Cable Connection table (see page 17) the pin numbers shown in the
right-hand columns relate to RJ45's .
2. Ensure that both the cable and wires are clearly labelled with the connection
type. Note that each circuit displays in INDeX programming as two channels.