VHF/UHF Half Duplex Data Radio Modems

Radio Network Packet Protocol

Designed and manufactured in-house, Crescendo is a series of digital data radio modems designed for use in large scale wide area point-to-point and point-to-multipoint industrial systems.

The radios provide a high-speed reliable link over narrow band channels for telemetry and SCADA radio applications requiring information or control of one or multiple remote stations.

The split port radio modem allows for direct connection to underground communication head-ends making the radio modem ideal as a leaky feeder radio solution.


Leaky Feeder application
  • Switching Bandwidth 148 MHz – 174 MHz (VHF) and 380 MHz – 520 MHz (UHF)
  • 5 Watt transmit power (software selectable)
  • Up to 30km line of sight*
  • 19,200 bps (or 9600 bps) air data rate
  • Multi-mode LED front panel display for diagnostics, including RSSI meter
  • Windows-based GUI support for configuration and remote diagnostics
  • Protocol addressing and routing support, DNP-3, Modbus and IEC 870 compatibility
  • Store-and-forward repeaters for large-scale networks and coverage expansion
  • Ethernet version available

VHF Radio

VHF Product Brochure


UHF Radio

UHF Product Brochure


Split Port Radio for Leaky Feeders

Split Port Product Brochure



The Crescendo series is suited for industrial applications in Utilities, Mining (e.g. underground wireless communications, leaky feeder systems, fleet monitoring), Agriculture (e.g. automatic start stop, remote irrigation, remote monitoring, wireless SCADA applications) and Transport (e.g. automated rail control, wireless monitoring) where reliable long distance data transfer is critical.

The data radio can be used in small or large scale telemetry systems, with almost any PLC, RTU, HMI or DCS vendor for monitoring and control of critical assets.

Telemetry applications also inlude pipeline monitoring, pump station and tank control, irrigation, fan and pressure control, and environmental monitoring.

The radios are also used in complex GPS systems for fleet tracking and management, and high precision correctional systems for machine control and automation.


Switching Bandwidth    The user can select any 6.25kHz raster frequencies with the easy-to use inbuilt menu or Windows configuration software.
Data Reliability    User selectable Automatic Repeat Request (ARQ) offers a high level of data reliability. The immediate re-transmission of data ensures that the user will not encounter end-to-end errors or data loss even in hostile environments.
Diagnostics at a Glance    The front panel LEDs display diagnostic information indication such as Receive Signal Strength (RSSI), transmit power, radio temperature and RS232 port status.
Data Mode Options    With data and packet-driven modes available, the Crescendo supports point-to-point, connection based and broadcast modes of communication.
Easy Network Management    The user is able to view diagnostics and change the settings of other remote radios within a network from a single point.
Data Integrity    Over the air data is encapsulated with Forward Error Correction, data interleaving and Cyclic Redundancy Checksums (CRC) for high level data protection.
Easy Network Configuration    The Cruise Control software allows the user to configure, save and upload radio configuration settings. This allows for multiple radios to be configured more efficiently.

Dimensions: 188mm x 102mm x 47mm
Weight: 700g
Construction: Powder coated aluminium

Serial Data: RS-232 Asynchronous with handshaking
Interface Speed: 300bps to 115200bps software selectable
Error Rate:-104 dBm for less than 1x10-6 BER (9600bps)
-102 dBm for less than 1x10-6 BER (19200bps)

Operating Voltage: 9V to 16V DC (negative ground)
VHF Operating Current:
- Transmit @12.5V 1.19A nominal @ 5W
- Receive @12.5V 80mA nominal
UHF Operating Current:
- Transmit @12V 1.7A nominal @ 5W
- Receive @12V 1A nominal
Operating Temp: -10 to + 60 deg C (-30 to +70 deg C version available)
Operating Humidity: Up to 95% non-condensing relative humidity


Antenna: BNC Female (50 Ohm), Dual BNC for Split Tx/Rx port option
Serial: 2 x DB9 RS-232 Female
Power: Phoenix PH1776508 (mating connector supplied)

Frequency Range:
VHF: 148 MHz to 174 MHz software programmable
UHF: 380 MHz to 520 MHz software programmable
Air Data Rate: 19.2 kbps (25 kHz channel), 9.6 kbps (12.5 kHz channel)
Duty Cycle: 100%
Channel Bandwidth: 12.5kHz or 25kHz (model specific)
Compliance: Designed to ACA, ETSI (planned) and FCC
Modulation: Nyquist-shaped 4-level FSK
Tx key up Time: less than 1mS
Data Turn-around Time: <10mS
Transmit Power: 1.0mW (0dBm) to 5W (+37dBm)
Mode of Operation: Single-port half duplex, Split-port half duplex


RFI-150 HWH: Crescendo VHF, Half Duplex, Wide Band, 19200bps
RFI-150 HNM: Crescendo VHF, Half Duplex, Narrow Band, 9600bps
RFI-150 HNL: Crescendo VHF, Half Duplex, Narrow Band, 4800bps
RFI-150 SWH: Crescendo VHF, Split Antenna Port, Half Duplex, Wide Band, 19200bps
RFI-150 SNM: Crescendo VHF, Split Antenna Port, Half Duplex, Narrow Band, 9600bps
RFI-150 SNL: Crescendo VHF, Split Antenna Port, Half Duplex, Narrow Band, 4800bps

RFI-450 HWH: Crescendo UHF, Half Duplex, Wide Band, 19200bps
RFI-450 HNM: Crescendo UHF, Half Duplex, Narrow Band, 9600bps
RFI-450 SWH: Crescendo UHF, Split Antenna Port, Half Duplex, Wide Band, 19200bps
RFI-450 SNM: Crescendo UHF, Split Antenna Port, Half Duplex, Wide Narrow Band, 9600bps
RFI-450 HWM: Allegro UHF, Half Duplex, Wide Band, 9600bps

*Maximum practical point-to-point distance with line of sight and suitable antennas.