Product manual

Configuration directions, Limitations of the system
Technical Product Manual - DCT1800-GAP
TD 92093 (1/LZBNB 103 108 R4D) / 2006-03-09/ Ver.C
© 2006
6
60 cordless phones and an LTU can interface 8 cordless phones. A DTU with CCS firmware can
interface up to 60 simultaneous calls i.e. not related to the number of cordless phones. The CPU
firmware limits the number of cordless phones to 600. When using analogue lines the maximum
number of cordless phones depends on the LTU board:
• ROFNB 157 25/2: 224 cordless phones (see paragraph 2.3)
• ROFNB 157 25/1: 256 cordless phones (8 LTUs per modular cabinet due to ground strip) or 224
cordless phones if earth signalling is used. (Phased out.)
The maximum number of cordless phones depends on the Grade Of Service (GOS) and the traffic
capacity of the radio exchange configuration.
CPU firmware
The memory space reserved by the CPU for each type of board and for cordless phones is limited to
a maximum of 600 cordless phones, 248 CLCs, 20 DTCs and 272 LTCs (34 LTUs).
Note that the number of base stations is 248 when using CPU2 but limited to 120 when using its
predecessor CPU. The practical number and cordless phones is given above.
Cabling
When the cable length is only data limited, base stations may be connected on a distance of up to
3.5 km when using CLU boards, or 2.1 km when using CLU-S or SLU boards. Where the cable length
is power limited the distance depends on the powering method that is used (see chapter
6).
In case an other cable is used between the radio exchange and the PBX to cover a longer distance,
this cable should not attenuate more than 6 dB at 1.024 MHz (e.g. a cable with an attenuation of 2
dB/100 m at 1.024 MHz gives a maximum distance of 300 m).
CLU and LTU cables are shielded cables which must be tied to earth by using the ground strip at the
bottom of the cabinet. This ground strip provides cable connections for any combination of up to 8
LTU, SLU, CLU and CLU-S boards.
2.2 Modular cabinet powering restrictions
Although the modular cabinet has place for 9 boards, not all board combinations are allowed due to
power limitations of the DC/DC convertor on the backplane. This convertor is specified as follows:
+5 V can supply 40 W at maximum
+12 V can supply 12 W at maximum
−12 V can supply 12 W at maximum
total must be ≤40 W
Table 1 shows the maximum power consumption (worst case) per board type. From this table, it can
be calculated if a configuration matches the power requirements. The values given for the ±12 V of
the LTU, indicate the power consumption in case all LTU circuits are off-hook.
Note:
Due to a minimum required power consumption from DC/DC convertor, at least two boards must be
present in each cabinet.