Wireless technology: Device bridges the gap between RFID, sensor networks

By Control Engineering Staff February 15, 2007

Keeping up with the flood of wireless industrial instrumentation and networking equipment can be difficult. Hardly a day goes by without a new product of some sort. Occasionally, a technology emerges that offers an intriguing new wrinkle and closes a gap between different levels of coverage.

Machine Talker Inc . supplies a line of devices with the same name to bridge the space between conventional RFID tags and wireless instrumentation mesh networks. The best way to think of them is as an intelligent RFID system. Imagine a device with the following features on one board:

Radio transceiver

Temperature sensor

Light detector




UART for serial I/O

A/D converter

The original applications for these centered on freight and shipping uses. The device is capable of monitoring its location and conditions, with capability to store this information or share it with nearby devices or gateway. Multiple Machine Talkers in adjacent containers on a ship communicate with each other and share information via a self-forming mesh network. If one experiences a high temperature or impact, the appropriate sensor will detect and record it.

When something offers all these capabilities and is not very expensive, creative people will find new uses for it. Sense-Comm Technology is now using Machine Talkers as transmitters to network instrumentation for petroleum tank farm monitoring. The first sensors include radar level detectors, power factor meters, current probes, flow, pressure, and motion detectors.

Because the unit has an A/D converter, it can serve as a proxy for any type of instrument and link it to a mesh network with other Machine Talkers. With appropriate programming, a Machine Talker can be instructed to perform many functions. For example, it can monitor a process variable, but only send out a report under specific circumstances. As long as things are happening as they should, it remains quiet and does not transmit.

“Using a Java-based API, Machine Talkers can be programmed to monitor events, maintain records, and service all types of sensors,” says Roland F. Bryan, president and CEO. “In one application, they monitor and report on goods in transit and the shipping containers themselves; in another, they permit external connection of industrial sensing devices. In both applications, the same Talker product is used, differing only in their respective software.”

This technology offers a very interesting package with a lot of potential for creative engineers. Machine Talkers will likely turn up in a wide variety of applications.

Control Engineering Daily News Desk Peter Welander , process industries editor