National Communications Page 3
PRODUCT DESCRIPTION
The SSU also allows for a primary audio feed, if connected, that will be
supplied to all speakers at all times.
This primary audio feed will then be replaced by the TDU message, only
on the appropriate speaker, whenever the TDU is triggered. The primary
audio feed is then reconnected at the end of the TDU message.
Speakers can be located up to 100m from the TDU unit, or greater than 100m
from the TDU if low resistance wiring is used.
The remote speakers connect to the SSU via a female 25 pin D type
connector. Each speaker has been allocated a specific pin position (see
page 6).
This equipment supports unpowered 4 ohm speakers up to 5 watts or 8 ohm
speakers up to 2.5 watts. Alternatively, powered speakers, or an external
amplifier can be used for greater volume output.
Power for the SSU and communication between the SSU and the TDU is
achieved via a supplied 6 wire telephone cable, which connects to an RJ11
format 6 position communications port.
The SSU has 2 identical communications ports that provide for power and
communication between the SSU, the TDU and other TDU accessories, in
a DAISY CHAIN fashion.
It does not matter which of the identical communications ports are used for
input or output. A single 6 wire telephone cable is supplied with all TDU
accessories. There is no need for any other external connections.
The SPEAKER SWITCHING UNIT (SSU) accessory is available in 3 separate
configurations :
SSU-4
- 4 Speaker output unit for the Talking Display Unit
SSU-8
- 8 Speaker output unit for the Talking Display Unit
SSU-12
- 12 Speaker output unit for the Talking Display Unit
