Radio Modems

RM9600 Features

The RM9600 Series of Radio Modems are a range of UHF multi-channel transceivers, incorporating a GMSK baseband modem and RS232/RS485 serial data interfaces.

RS232/485 Interface
16kbps over-air rate
500mW Transceive Radio Modems
406-470MHz
FEC, ARQ and Repeater modes

Brief Description:

As with all RDT Radio Modem products, the RM9600 provides fully transparent operation regardless of the serial data protocol. Over-air speeds up to 16Kbps are achievable and serial data can be input at various baud rates up to 19,200bps. Access to all user configurable parameters is possible using the on-board switches and operational status is easily monitored using the standard LED indicators.

Models currently available include the RM9600 Modem Card for OEM customers, the RM9600B Aluminium housed model and the RM9600E & EX, IP67 housed units with integral power supplies.

A brief summary of features includes addressing capability, user selectable RF power level and frequency of operation, built-in repeater facility, Forward Error Correction (FEC), Automatic Repeat Request (ARQ) and MODBUS compatibility (ASCII & RTU).

The RM9600 utilises RDT's unique multi-channel UHF transceiver which is available as a separate module to OEM customers wishing to take advantage of the superior design, build quality and performance for which the products have a world-wide reputation.

Applications include Alarm Systems, Data acquisition, Remote Metering, Remote Control Systems, Warehousing and Despatch, SCADA, Security Systems, Video Surveillance Systems, Telemetry, Traffic Information and Control Systems etc.

The RM9600 products carry the CE mark and meet various UK, European and world-wide radio approval specifications including ETS 300 113, ETS 300 220 and MPT1329. Details are available upon request.

Technical Information

  • User selectable RF channel, Address and Tx power level
  • LED indicators for, radio functions, signal strength and serial line status
  • Forward Error Correction (FEC)
  • Automatic Repeat Request (ARQ)
  • UHF FM Synthesised Radio Transceiver
  • Transparent 9600bps serial data transmission
  • RS-232 & RS-485 Serial Data Interfaces
  • 6 modes of operation including Asynchronous, Modem and Repeater

Power Supply

The RM9600 board requires a 12V d.c. power supply which should be well filtered and regulated. On-board voltage regulator circuits will maintain a constant sup-ply of voltage to the radio and logic circuits, however, excessive noise, fluctuations and interference on the d.c. supply may cause loss of data.

Antenna Selection

The antenna should be designed for use at the operating frequency in the 406-470MHz UHF frequency band. The radio range achieved will be dictated by the land topography between the nodes.

Ranges quoted below are for guidance only, distances vary according to terrain and obstructions. In many situations increasing antenna height can greatly improve signal strength, and the RSSI test mode can be used for signal strength indication.

Yellow LEDs indicate minimum acceptable signal, green LEDs indicate excellent signal strength. Coaxial feeder cable is available in many forms, 50ohm impedance cable with low loss should always be used, note that 3dB of feeder loss will reduce radiated power by half.

In some applications where maximum range is required, directional antennae with gain can compensate for feeder loss provided that the maxi-mum radiated power limit is not exceeded (in most countries this is 500mW).

When low loss RG213/U or UR67 coaxial cables are employed N-type RF connectors should be fitted in conjunction with the Antenna Bulkhead Cable Kit (ENC/007) to convert from the SMA socket on the radio module to N-type RF connectors on the coaxial cable.

Antenna Type, Range and Gain:

  • ½-Wave Whip:- 1 km Omnidirectional, -3dB, Enclosure Mounted, Short range for general use
  • End-fed Dipole:- 10 km Omnidirectional, 0dB, Pole Mounted, Medium range for general use
  • 8 Element Yagi:- 20 km Directional (40°), 10dB, Pole Mounted, Long range for directional use.