Adept floats ‘instrumentation cloud’
9 Jun 2010
Letchworth, UK – Adept Scientific of Letchworth, UK has added Tag4M WiFi sensor tag from Cores Electronic – an Austin, Texas-based technology company – to its range of data acquisition products. The credit card-sized device uses RFID and Internet technology to enable measurement and analysis of process parameters within an ‘instrumentation cloud’.
The WiFi tag collects analogue data and performs digital I/O; communicating directly with any commercially available WiFi access point (AP) or wireless router. An “extremely low” power consumption, meanwhile, is said to allow tags to operate on a standard 3V CR-123A lithium battery for several years – depending on the application.
When Tag4M initially boots-up it searches for and automatically associates with an off-the-shelf 802.11b/g AP. Each unit has its own permanent MAC address and it shares a common SSID (default network name) with the AP so it can transfer data and accept commands from any predetermined web page. Users can also connect the AP to a LAN to operate a Tag4M in local mode.
The WiFi radio chip and ceramic antenna specification has a range of 50m indoors and 100m outdoors. Linked to an AP, the tag sends digitised sensor data over the Internet for any web-based applications to use.
According to Adept Scientific, with web-enabled applications starting to emerge, the ‘instrumentation cloud’ scheme has major potential in process applications ranging from sensor interfacing to predictive maintenance and industrial control.
For example, each tag can function as an embedded machine controller thanks to its on-board intelligence (32-bit RISC processor), memory (64k bytes) and 4 digital I/O lines that control relays or any other devices that require a TTL-level On/Off signal. The device can, therefore, run small control algorithms directly or it can respond to commands from larger control programs resident on the Internet.
Besides the WiFi link, the tag integrates a temperature sensor and provides five voltage/current input channels and four digital I/O lines. When transmitting it requires roughly 200mA and in Sleep mode consumption drops to < 10uA. This means that if the sleep period between readings/transmissions is one second, battery life is 52 hours; with a sleep period of 500 seconds lifetime extends to two years.
“Our WiFi tag and Web Page Instrument heralds a new way of collecting real-world data,” said company president Marius Ghercioiu. “Most wireless sensor units currently on the market are designed to work in Local mode with a computer running a specific software application. In contrast, we designed the Tag4M to interface with a web page, which can be hosted on any web-enabled hardware.
