That's what makes factories difficult places to install wireless data-collection networks. A new approach from The L. S. Starrett Co., Athol, Mass. (starrett.com), uses radio transmissions and a web of routers to cover thousands of square feet and still ensure accurate data collection.

Networks are constructed using a combination of three components: end nodes, signal routers, and a gateway. The end nodes are miniature radios that connect to the data-output ports on electronic measuring tools and gages. They work on most major brands of electronics, including CDI, Mitutoyo, Starrett, and Sylvac. The nodes transmit data to a router, which can be up to 100 ft away. And routers relay data to the gateway, which connects to a PC running Windows XP Professional through its USB serial port. The

system can have several routers and up to 100 nodes, letting it handle data from 100 different tools. Data travels to the gateway via the shortest or most robust path. Once the gateway receives data, it sends a confirmation signal back to the tool, indicating whether or not the data transfer was successful. If the gateway is down or busy, or the gateway signals an unsuccessful transfer, nodes can store data and resend it until it is safely recorded on the PC.