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USB serial converter for MOTOTRBO

The DMR921 provides a serial RS232 interface on the MOTOTRBO radios.


The interface unit DMR921 converts the USB interface on MOTOTRBO radios to an RS232 interface, allowing applications and hardware that only support RS232 to function over a DMR network.

The DMR921 converts the native USB interface on the MOTOTRBO mobile radio into RS232, but also performs the required initialisation of the MOTOTRBO USB interface. The radio can be configured and used for various applications with simple instructions being sent via the serial interface.

Typical applications include control of switches, water levels, flow, pressure and quality measurement in utilities, gas and water supply, energy/power supply, wind turbines and industrial automation systems.

Additional Resources


Supported Languages

• Change of channel and zone.

• Volume adjustment and loudspeaker control.

• Typing text in the display.

• Switching on/off scanner functions.

• Adjustment of transmitting power.

• Use of emergency call functions.

• Activation of the radios call system.

• Reception of calls.

• Remote control of radios.

• Text messages.

• UDP data communication between two radios or radios and a PC.

• Data transparent mode.

• Adjustable interface parameter.

Radio Hardware / Releases Compatibility
DM340x or DM360x Firmware Version at least 1.03.01.

IP Technology
PC or another application able to communicate with AT-commands on RS232 with the DMR921.

USB interface to connect DMR radio device (DM3xxx and DM4xxx).
RS485 to expansion Phoenix Contact Module.
Cable set for the connection to the radio included.

MOTOTRBO System Architecture
Single Site, IP Site Connect, Capacity Plus, Linked Capacity Plus.