Hartcran House, 231 Kenton Lane, Harrow, Middlesex, HA3 8RP, England Tel: +44 (0) 20 8909 9595, Fax: +44 (0) 20 8909 2233, www.radiometrix.com Issue 1, 01 August 2012 RPM2A UUUUHHHHFFFF RRRRaaaaddddiiiioooo PPPPaaaacccckkkkeeeetttt MMMMooooddddeeeemmmm The UHF Radio Packet Modem (RPM2A) is a low cost intelligent radio packet modem that enables a two way radio network/link to be simply implemented between a number of digital devices. The RPM2A uses addressable data packets with error checking, packet acknowledgements and retransmissions to achieve a reliable transparent wireless data link. Built for ease of use and rapid installation, the serial interface ensures direct connection to microprocessors or to RS232 port via RS232 driver while remote configuration enables post installation setup of the modem. Features Addressable point-to-point Point-to-Multipoint and broadcast modes Inverted RS232 interface at 5V or 3VCMOS level DTE speed 600-115200bps Overall throughput: 17kbps with ACK 28kbps without ACK Single 5V or 3V supply 15mA during data streaming at maximum rate Flow control Hardware (CTS), None0 Available on 433.92MHz or 434.42MHz Usable range up to 300m Figure 1: RPM2A-433-17 Built-in command line configuration Built-in RF link diagnostics Remote over-air unit configuration Low operating current, Auto standby mode Conforms to European ETSI EN 300 220-3 and EN 301 489-3 Dimensions: 39mm X 23mm X 10mm Applications Telemetry and telecontrol EPOS equipment, barcode scanners, belt clip printers, stock control, job allocation Remote data acquisition system, data loggers In-building, environmental monitoring and control systems High-end security and alarm signalling Automated Monitoring and Control Systems Fleet management, vehicle data acquisition Evaluation platforms: RPM/SPM Eval kit Radiometrix Ltd. UHF FM Radio Packet Modem page 1 INTRODUCTION The RPM2A is a self-contained Radio Packet Modem module that requires only a simple antenna, 5V supply and a serial I/O port on a host microcontroller or PC. The module provides all the RF circuits and processor intensive low level packet formatting and packet recovery functions required to inter-connect any number of devices with serial port in a radio network. A continuous stream of serial data downloaded by a Host microcontroller into the RPM2A serial receive buffer is transmitted by the RPM2AS transceiver and willappea in the serial buffer of the addressed RPM2A within radio range. transmit / receive download download HOST RPM2A HOST upload upload Figure 2: Point to point wireless link with RPM2A + Host microcontroller 1. FUNCTIONAL DESCRIPTION The RPM2A is a connection oriented modem module for sending and receiving serial data via an RF communications link. The RPM2A handles all necessary protocol related functions of validation and retries to ensure error free and uninterrupted data is sent over the communications link. All data transfers between a pair of RPMS are fully acknowledged, thus preventing the loss of data. Bit coding and checksums are used on the data packets to ensure the validity of the received data at the remote end. Radio Packet Modem D0 Fast Radio Radio Packet Packet Modem Host BiM2A Controller (RPM) Controller Transceiver (FRPC) 64kbps 9.216MHz 8.192MHz Figure 3: RPM2A block diagram Radiometrix Ltd. UHF FM Radio Packet Modem page 2