User's Manual

SECTION 1: THEORY OF OEPRATION
M32450-25-FCCRpt.doc Page 3
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General Block Diagram
General 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 M32450-25 mobile 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 following data connectors:
 RS232 Serial Port DB9 Data Connector
 RJ45 Ethernet 10 Base T Interface Connector
 For further details on the Ethernet Controller, refer to the Crystal LAN
Ethernet Controller Product Bulletin (CS8900A-EthernetCtrlr.pdf)
available on the Product Documentation CD.
Microcontroller Manages the operation of the radio, the modem, and determines which
receiver provides a better signal from a given transmission. Also provides
transmit time-out protection in the event a fault causes the radio to halt in
the transmit mode.
Modem Converts serial data into an analog audio waveform for transmission and
analog audio from the receiver to serial data. Within a single chip it
provides forward error detection and correction, bit interleaving for more