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
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Chapter 2 Limitations of the system
The system limitations determine the number and type of system boards that can be placed in a
modular cabinet, number of cordless phones and base stations, distance between base stations and
radio exchange, cable connectors, powering method used, etc. Certain limitations may affect each
other. For example if the maximum number of LTUs are installed in a system, then it is not possible
to install the maximum number of base stations as there are not enough board positions nor enough
cable connections on the ground strip of the modular cabinet.
The limitations of the system have been divided in:
• Modular cabinet
• Modular cabinet powering restrictions
• Modular cabinet temperature limitations
2.1 Modular cabinet
Cabinet
Systems built up by modular cabinets may consist of up to 4 cabinets. Each cabinet provides space
for a combination of 9 system boards. This means that the total size of the system may be 36 system
boards. All boards, except for the CPU which shall always be placed in cabinet 1, can be placed in
any slot. But, due to the MCCB layout, power limitations and heat generation not all combinations are
allowed. Powering limitations of the modular cabinet are discussed in paragraph
2.2.
As a result a single cabinet has the following limitations per type of system board:
• 1 CPU, overall system limit
• 3 DTUs, limited by cabling
• A total of 8 SPU-Ss and SPU parts of SLUs are used in overall system limit
• The total number of CLUs, CLU-Ss, SLUs and LTUs is limited to 8 by ground strip. Of the CLUs,
CLU-Ss, SLUs only 7 may distribute power to base stations
• The power restrictions given in paragraph 2.2
•7 LTUs
1
(ROFNB 157 25/2). For more information, see paragraph 2.3
Connection board
A modular cabinet has only one connection board which is factory fit. This board is called the Modular
Cabinet Connection Board (MCCB). The MCCB provides earth-signalling connectors for 7 LTUs, trunk
connectors for 3 DTU boards, and base station power connections for 7 CLU, CLU-S and SLU boards
in total.
Power supply
Modular cabinets can be powered by the power transformer, by the battery power unit or by an external
48 Vdc supply. The power transformer provides power for a single cabinet and at least 10 additional
base stations. Base stations may be powered by, or in combination with, an external source via the
cabinet.
1. ROFNB 157 25/1 and ROFNB 157 25/2 can not be used together in one system