RIM232-433 UHF Radio Modem


The RIM-232-433 Radio Modem provides a reliable wireless communications link between two serial devices. The RIM-232-433 can be used in a variety of data communications applications that require a simple to use invisible data link.

High speed data streaming permits point-to-point error free transfers upto 14400bps half duplex.

Repeater mode enables the Radio Modem to extend the effective operating range of a point-to-point link by forwarding data packets to a maximum of 3 repeater hops. 

The Radio Modem uses unit & site addressed data packets with error checking and packet acknowledgements to achieve a well managed highly reliable wireless link. The on-air data rate is selectable from 600 to 14400 bps, thus improving network access for multiple point-to-point links within close proximity.

Configure the RIM-232-433 for point-to-multipoint broadcast mode and combine with any number of intelligent host computers/ controllers to implement very large networks.

The RIM-232-433 Radio Modem supports a range of built-in diagnostic functions that can be used for network interrogation, network problem finding and radio site & range testing.


  • Addressable Point-to-Point, Point-to-Multipoint and Broadcast Multidrop
  • Licence exempt operation on 433.92MHz
  • Serial protocol. 8 data/1 stop/ no parity
  • DTE Speed selectable 600-115200bps
  • Air data speed selectable  600-14400bps
  • DTE flow control - hardware/software/none
  • 96 byte serial receive/transmit buffer
  • On-air data encryption and 100% code balancing.
  • Range up to 300m with fixed antenna
  • Increased range with external antenna
  • Simple built-in command line configuration
  • Built-in RF link diagnostics
  • Remote over-air unit configuration
  • Front panel modem status indicators
  • Low operating current. Auto standby mode
  • Low profile enclosure with integrated PP3 battery.
  • DIN rail mounting option on SMA model.
  • Uses 9V PP3 battery or 7-15V DC power supply.


  • Operating voltage of 7 to 15VDC
  • Average current of 36mA (data streaming).
  • Standby current of 15mA.
  • Shutdown current of 440uA, for long-term battery operation (DTR activated).
  • Physical: Width 62mm, Depth 24mm, Height 103mm. (excludes antenna)
  • Operating temperature of 0 to 55 degrees C


  • Radio approval EN 300-220-1,
    ETS 300-683, AS4268.2 
  • 433.920 MHz centre frequency
  • Transmit power 10mW
  • Receiver sensitivity -100dB for 1ppm BER
  • Standard aerial: Fixed stubby helical
  • Aerial option 1: Fixed 1/4 wave
  • Aerial option 2: SMA female connector


The following table outlines the nominal operating range of the RIM232 Radio Modem. Please note that the ranges listed will vary depending on the level of surrounding RF interference, obstacles near or in the line of sight and other environmental factors.

Model and Antenna


Outdoor (1)

RIM232-433 - Fixed helical



RIM232-433/W - Fixed 1/4 wave whip



RIM232-433/S + RIA433H-SMA



RIM232-433/S + RIA433D-3DB (2)


4km (3)

1. Outdoor range testing performed in a central business district environment.
2. The use of high gain antennas may result in radiated power levels exceeding the licensed levels permitted in the country of use.
3. In ideal conditions a fully functional range of >4km has been achieved. Unit A on a 100m hill with line-of-sight to unit B on 100m hill.

Product Features