TXL2和RXL2設計的單向無線電連接方案

TXL2和RXL2模塊是Radiometrix 公司的9600波特多路OEM無線調制解調器,工作頻率為歐洲的433MHz ISM頻段,提供單向無線電連接方案. TXL2/RXL2與EN 300 220-3 和EN 301 489-3 兼容,具有高質量穩定的基準晶體和低噪音合成器/VCO,以及SAW前端濾波器和多級陶瓷IF濾波,發送功率+10dBm,接收靈敏度-107dBm,主要應用在手持終端,PDA,工業遠程信息處理,建筑物內環境檢測和控制,遠程數據采集系統,艦艇,汽車數據采集等.本文介紹了TXL2和RXL2主要特性,指標和方框圖,以及和MCU直接連接框圖, 通過RS232線路驅動器/接收器連接到RS232端口框圖.

The TXL2 and RXL2 modules are 9600baud simplex multi channel OEM radio modems in a Radiometrix SIL standard footprint, operating on European 433MHz ISM band. The TXL2/RXL2 pair act as a transparent serial cable to attached host. Unlike raw FM radio modules (e.g. TX2A/RX2A), TXL2/RXL2 will take care of preamble, synchronisation, bit balancing and error checking along with automatic noise squelching.

The TXL2/RXL2 pair provides a one-way radio link. Provided no two devices attempt to transmit simultaneously no further restrictions on data transmission need be made, as all transmit timing, valid data identification and datastream buffering is conducted by the units. Synchronisation and framing words in the packet prevent the receiver outputting garbage in the absence of wanted RF signal or presence of interference.

For multiple radio systems a TXL2/RXL2 can be set to 1 of 8 unique addresses. As well as having unique addresses, the TXL2/RXL2 allow operation on one of 5 pre-set frequencies in the 433MHz band. These frequencies are non-overlapping and simultaneous operation of TXL2/RXL2 pairs in the same area on different channels will be possible. Units are supplied on 433.925MHz (Ch0) as default

TXL2/RXL2主要特性:

Conforms to EN 300 220-3 and EN 301 489-3

High quality, stable crystal reference

Low noise synthesiser / VCO

SAW front-end filter

Multi-stage ceramic IF filtering

Single conversion superhet

Serial modem baud rate at 9600bps (simplex)

Addressable point-to-point

5 serial select wideband channels

TXL2/RXL2主要技術指標:

Operating frequency: 433.925MHz (default)

Modulation: 16kbps bi-phase FSK

Supply: 5V at 28mA transmit, 22mA receive/idle

Transmit power: +10dBm (10mW)

Receiver sensitivity: -107dBm (for 1% BER)

32 byte data buffer

Adjacent channel rejection: 60db @ ±320kHz

Receiver Blocking: >75dB

TXL2/RXL2應用:

Handheld / portable terminals

PDAs, organisers & laptops

Industrial telemetry and telecommand

In-building environmental monitoring and control

Remote data acquisition system, data logging

Fleet management, vehicle data acquisition

圖1.TXL2方框圖

圖2.RXL2方框圖

圖3.TXL2和RXL2和MCU直接連接框圖

圖4.TXL2/RXL2通過RS232線路驅動器/接收器連接到RS232端口框圖