External Products; External Modem - Tait TM8000 Series Applications Manual

5.1

External Products

5.1.1

External Modem

Data Flow
Figure 5.1 Basic system configuration using two external modems and radios
RF connector
radio
1
auxiliary
connector
RF connector
radio
2
auxiliary
connector
98 Connecting Third-Party Products
Figure 5.1 shows a simple point-to-point data link system using two radios
and external modems.
radio
connector
radio
connector
1. DTE 1 transmits the source data in serial form to the external
modem 1. The DTE can be a PC or a data head.
2. The modem encodes the data into a baseband modulation signal
which is suitable for over-the-air transmission, and feeds it to radio 1.
3. Radio 1 uses the baseband modulation signal for frequency
modulation of the RF carrier signal, and then sends the modulated
signal over the air (via a repeater, if necessary).
4. Radio 2 receives the modulated signal, recovers the baseband
modulation signal from the RF carrier, and then feeds the baseband
modulation signal to external modem 2.
5. External modem 2 decodes the baseband modulation signal into serial
digital form and feeds it to DTE 2.
DTE 2 can also be the source and DTE 1 the destination, however because
the TM81xx is a simplex radio, simultaneous data flow in opposite directions
is not possible.
DTE
connector
external
modem
1
DTE
connector
external
modem
2
TM8000 3DK Hardware Developer's Kit Application Manual
September 2003 © Tait Electronics Ltd
serial data
connector
DTE 1
serial data
connector
DTE 2