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Technical Specification 7
Specified Systems
The DHY-04 is suitable for connection to any exchange line forming part of a
Public Switched Telephone Network, PSTN, or a Relevant Branch system for
PSTN lines or any extension. This equipment is not suitable as an extension
to a payphone. A definition of Relevant Branch System for PSTN is given in
BS6789: Section 6.1: 1986 Clause 2.9; including the note to that clause.
Ringer Equivalence Number
The REN=1 marking on the rear of this equipment relates to the
performance of the apparatus when used in combination with other items
of appa-ratus.
The REN indicates the maximum number of items that should be connected
simultaneously to the line. This equipment may be connected with series
apparatus up to REN = 4 maximum.
Accessory Ports
Barriered Ports - The Handset series connection complies with BS6301.
Accessory Ports - Mic/Line Input, Main Output, Conferencing Port, Serial
Port, Ethernet Port & Remotes
Conditions
This apparatus is not designed for use under controlled conditions of
temperature and relative humidity.
Series Connection
When connected into the loop connection between the main apparatus and
the PSTN, this apparatus introduces a voltage drop at a current of 40mA of
0.300V.
The apparatus should not be used in conjunction with other series
connected apparatus such that the aggregate declared voltage drops,
together with that of any relevant wiring at 40mA, exceeds 2.0 volts.
Facilities
This apparatus has been approved for use as a telephone hybrid unit (four
wire to two wire converter) and for use with a series connected simple
telephone. Any other usage will invalidate the approval of the apparatus
if as a result it then ceases to comply with the standards against which
approval was gained.
Statutory Mark
Approved for connection to telecommunications systems specified in the
instructions for use subject to the conditions set out in them.