User's Manual

Eclipse2 Technical Manual, 3-Aug-12 Page 11 of 17

Connecting with Ethernet

Ethernet is the interface of the base station, especially for remote monitoring and controlling via an

Network. Each base station has a unique IP address, to connect, the host PC must be in the

same subnet with the base station.

Connecting with USB

The front-panel USB connector can be also used for connecting to a computer, IP Commander

Software loads a USB driver to recognize the base station.

Technical Description

The

transceiver consists of three sub assemblies: Control Board, Interface board, and RF modules.

Control Board

The Control Board is a multi-layer, double side component mounted PCB assembly. The most

important parts of the base station, such as CPU, DSP and digital IF receiver, are embedded in this

master board, two 40-pin connectors on this board allows user inserting/removing it from the

interface (main) board.

The CPU (U1) is a single chip 32-bit RISC processor, it controls all the operating functions of the

base station. The support chips include a 16Mbyte Flash (U9) and 64Mbyte SDRAM (U7, U8). The

base station software and configuration databases are stored in the Flash memory. The system

serial bus and GPIO of the RISC processor are connected to the system interface board via two 40-

pin connectors.

The 10/100Mbps Ethernet Physical Layer single chip transceiver (U10) provides the interface

between RISC processor and the Ethernet. A serial ATA cable is used for connecting between the

Master board and System interface board.

The DSP (U2) is a 32-bit fixed-point digital signal processor, which provides the base band

processing including modulation, demodulation, RSSI/SINAD calculation, CTCSS encoding/decoding

and audio processing of the base station. The DSP software is modularized, the modulator,

demodulator, pre-emphasis, de-emphasis, filters and gain are individual modules, user can connect

or disconnect any module by the Service Kit software for different applications. The DSP also

controls the frequencies of the PLL chips within the RF modules. The digitized audio signal

interfaced to the CODEC of the system interface board is via the DSP serial port.

The digital IF receiver consists of an ADC (analogue to digital converter, U4) and a DDC (digital

down converter, U3). The pre-filtered analogue IF signal from the receiver module is fed to ADC,

converted to the digital IF and passed to the DDC via the parallel bus, the DDC mixes the incoming

digital IF with the internal Numerically Controlled Oscillator (NCO) frequency signal to produce the

0Hz IF, the DDC also provides decimating and further filtering for the IF signal. The output from

the DDC is in complex I/Q format, sent to the DSP for demodulating via the serial bus.