Replacing The Tait T2000-A81 Board; Differences Between The Tm8000 And T2000-A81 Interfaces - Tait TM8000 Series Applications Manual

6

Replacing the Tait T2000-A81 Board

6.1 Differences Between the TM8000 and T2000-A81
Interfaces
TM8000 3DK Hardware Developer's Kit Application Manual
September 2003 © Tait Electronics Ltd
This chapter describes the issues regarding the transfer from a combination
of Tait 2000 radio and T2000-A81 board to the TM8000 mobile radio.
It will also help integrators who are considering interfacing an external
product to the TM8000 auxiliary connector.
The T2000-A81 board is a low-cost interface board, which permits the
break out of a number of options connections of the T201X mobile radio.
It allows third-party devices such as mobile data terminals or data modems
to be connected to the T201X.
It is important to understand that there are some differences between the
TM8000 and T2000-A81 interfaces.
1. Physical connector – The T2000-A81 uses a high-density 15-way
D-range connector (three rows of five pins). The TM8000 auxiliary
connector is a standard miniature 15-way D-range connector (one
row of seven and one row of eight pins). The auxiliary connector is
described on page
2. Technology – The T2000-A81 is a PCB-based hardware interface
and none of the connections to the T201X are programmable. On
the other hand all of the digital I/O lines on the auxiliary connector
on the TM8000 are programmable to a wide range of functions.
3. Signal levels – Due to the nature of the two radio designs both the
digital interface and analogue levels will have differing levels.
The current handling capability of digital outputs may also vary.
The tap-in and tap-out audio lines in the TM8000 are designed to
provide access to a number of points in the audio chain. The input
and output level for these taps has been set at –10dBm for 60% of full
system deviation. The tap points are illustrated in
Tap Out Lines" on page
4. Microphone mute – While the TM8000 does offer an equivalent
microphone mute function (see
page 57) the preferred means of muting the microphone is to use
audio steering based on the three PTT lines provided by the product.
In this case the fist microphone PTT is used only to indicate to the
third-party device that it is being activated. This action can be
mirrored in a digital output.
5. RSSI output – The RSSI output of the TM8000 is committed to a
pin on the auxiliary connector.
20.
80.
"Mute External Audio Input" on
Replacing the Tait T2000-A81 Board
"Audio Tap In and
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