Page 32 of 48
System requirements
553-2691-100 Standard 8.00 August 1996
PE cabinets and shelves
The power unit and QBL16 Distribution Unit can be used with PE cabinets of
the following vintages:
— QCA8: vintage E or subsequent
— QCA7: vintage D or subsequent
— QCA23, QCA28, QCA37: all vintages
These cabinets are equipped with wiring harnesses that incorporate a cable
and P14 connector. The connector plugs into the P14 socket of the power unit
or distribution unit, and the wiring harness provides –150 V dc power
distribution to the PE shelves in the cabinet.
The cabinets used with the power unit or power distribution unit must contain
shelves of the following vintages:
— QSD3, QSD7: vintage B or subsequent
— all other PE shelves: all vintages
Line circuit cards
The circuit cards used for the 500/2500-type telephones depend on the
companding law used with a given system. In general,
µ
-Law companding is
used in North America and A-Law companding in parts of Europe and Asia.
These cards are based on the standard 500/2500 line cards but include –150 V
lamp control circuitry for the neon lamps on the 500/2500 Message Waiting
telephones.
The circuit cards are available in single density (four circuits per card) and
double density (eight circuits per card) configurations. Single density cards
can be used with all systems but are superseded by double density cards that
can be used only with systems designed for double density equipment.
The following are the available single density 500/2500 Message Waiting
line cards:
— QPC267 (
µ
-Law)
— QPC286 (A-Law)