20
Description of the Radio Interfaces
TM8000 3DK Hardware Developer’s Kit
Application Manual
September 2003
© Tait Electronics Ltd
2.3
Auxiliary Connector
The auxiliary connector is the standard interface for external devices that are
typically connected to a radio. The auxiliary connector is a 15-way standard-
density D-range socket. The auxiliary connector provides a serial port, three
programmable input lines, four programmable digital I/O lines and audio
I/O.
Note
The space for a mating plug is limited to 41 mm in width and
18 mm in height. Although most plugs will fit this space, it is rec-
ommended to test the plug to be used before manufacturing a
cable. The internal options kit (described
) includes a
suitable plug (Tait IPN 240-00020-55).
If the auxiliary cable is longer than 1 metre it is recommended to shield the
cable and connector backshell.
shows the recommended
shielding arrangement. The earth braid wire (bare copper) and aluminium
foil should only be earthed at the radio end of the cable.
The I/O lines can be programmed for a variety of functions, logic levels and
in some cases direction (refer to
“Programmable I/O Lines” on page 39
Audio lines can also be programmed to tap into or out of different points in
the audio processing chain (refer to
“Audio Tap In and Tap Out Lines” on
Figure 2.5
Recommended auxiliary cable and connector shielding
cable insulation
aluminium foil
earth braid wire
signal earth wire
analogue ground pin
metal backshell
metal D-range shroud in
contact with backshell
metal cable clamp