User's Manual

F32700N25.doc Page 3
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Section 1: Theory of Operation
Digital Board
Inputs/
outputs
Micro-
controller
Injection
synthesizer
Receiver
Transmit
modulation
Transmitter
Modem
Antenna
TR
Switch
RF Board
Transmit
Processing
Figure 1: Block Diagram
Block Diagram Definitions
For increased data security, the modem supports the Federal Government
developed Digital Encryption Standard (DES) data encryption and decryption
protocols. This capability requires installation of third party, Internet Protocol
(IP) compliant DES encryption and decryption software on the system.
The F32700N25 Fixed Radio is comprised of two (2) circuit boards, the digital board
and the RF board.
The digital circuit board contains the following sections:
Input/Output Circuitry associated with the radio’s DB9 data connector
providing all the RS232 data and handshake functions,
including the necessary level changes.