An embedded low power radio modem for European use

Edited by the Processingtalk editorial team Dec 22, 2004

Circuit Design has recently developed an embedded low power, long range 434 MHz modem for industrial applications, meeting the requirements of the European standard R and TTE Directive 1999/5/EC

Designed for embedding in industrial equipment, the MU-1 goes on sale in Europe from June this year.

The MU-1 is a radio modem for serial data communications that uses the UART serial interface to the host system, while data input/output is performed with simple commands.

A narrowband radio component using the Circuit Design leading narrowband radio technology, a CPU for control, and high frequency circuitry are enclosed in a robust metal shield case.

The internal CPU ensures stable operation of the high performance radio component, and besides processing data, it communicates with the host system.

While the MU-1 is no bigger than conventional modules that contain only a radio component, it offers serial data communication with dedicated commands and reliable long distance communication with good noise resistance.

It is highly versatile, making it suitable for a wide range of applications that require an industrial use radio modem.

The MU-1 meets the requirements of the European standard R and TTE Directive 1999/5/EC, and operates within the harmonized 434 MHz ISM band, with 64 channels in 25 KHz steps.

The complicated PLL control and associated data input timing control required with a conventional radio module, insertion of the preamble before the data, and the radio data link are all handled by the internal CPU of the MU-1.

In addition, the circuit board which is optimally designed for high frequencies, is mounted with all the components required for control of the radio component.

The MU-1 also comes with an antenna, so that the user can concentrate on development of the host system without having to pay much attention to the high frequency element.

As a result, it is possible to shorten product development time significantly, and reduce the number of parts.

In order to simplify the development of data acquisition applications wirelessly using a computer, Circuit Design will simultaneously release interface kits that enable use of USB and LAN interfaces in addition to the RS232C interface.

These interface kits include an interface board, MU-1, cables, and an evaluation software program so that the user can check the operation of the product straight away.

The features of the MU-1 are as follows.

* Controlled using dedicated commands through the UART interface - the UART serial interface is used for the user interface.

* Transmitting and receiving data, and changing and setting communication parameters and Link IDs is possible using dedicated 2-character commands.

* A highly reliable, industrial use modem - a design that offers the reliability, shock resistance, vibration resistance and high quality required for use in industrial applications.

* An operating temperature range from -20 to 60C using a unique temperature compensation circuit.* Narrow band FM and double superheterodyne receiver circuits with high receiver sensitivity enable stable, long distance communication.

* The receiver uses a SAW filter with sharp filtering characteristics to prevent radio interference.

* Flexible Link IDs can be set, enabling error-free communication between multiple devices, and a variety of system configurations.

* Achieves stable operation with all high frequency circuits enclosed inside the shield case.* Support for a variety of interfaces - An RS232C interface kit, USB interface kit, and LAN interface kit are available to enable connection to a PC or network.

A full technical article describing the application of these devices is also available.