No machine is an island—at least, not anymore.
To help machining centers and machine tools overcome their traditional standalone nature and begin to communicate more freely, the Association for Manufacturing Technology and the University of California (UC) Berkeley’s RAD Lab and the Georgia Institute of Technology have developed an open, royalty-free communications protocol, MTConnect, and launched it in September at the 2008 International Manufacturing Technology Show in Chicago. This development began following calls for a united machine communications method at the previous IMTS two years earlier.
Based on XML and HTTP, MTConnect seeks to foster interoperability between machines, controls, equipment and software by employing a standard vocabulary to gather, publish and distribute machine-tool data via Internet protocol (IP) and Ethernet networking. MTConnect’s developers say machines typically use numerous different data and communication methods, and so standardizing their language and its structural grammar was crucial for them to talk and understand each other. Users can learn about MTConnect, and even download its source code, at www.mtconnect.org. This can be used as-is, modified for special needs, reverse-engineered or used as a template to create an individual software interface that meets the standard’s requirements.
“MTConnect uses the basic software strategy of breaking down a problem and handling it in layers, and it applies that strategy to machine tools,” says William Sobel, of UC Berkeley’s RAD Lab. “This means getting data off a machine, doing minimal data handling, putting it in the same language and units and displaying that common data on MTConnect’s application interface. Because there are so many vertical machining standards, MTConnect’s broad standard works only on the data layer below them, but this means we can take any data, including OPC, and make it all look the same.”
To standardize data from individual machines, AMT and its academic partners collaborated to write MTConnect’s software adapter. This software takes data from proprietary devices, converts it to an intermediary format, sends it to an HTTP server-agent in response to a request and converts it into the right units at the same time. For example, during this year’s IMTS event, Sobel reported that LNS Machine Tools, Cincinnati, Ohio, specified and wrote its own MTConnect software adapter, installed MTConnect’s open software agent, configured it one morning, hooked it up and started displaying data coming in just six hours later. In fact, several builders at IMTS used MTConnect to receive parts’ specifications and other operating parameters from remote locations, used this input to run their machines at their exhibits and then reported back a variety of real-time performance results and condition data.
“The beauty of MTConnect is that it’s extensible to what users want to do with it,” says Paul Warndorf, AMT’s technology vice president. “However, it’s still very new. We’re just starting out, and there’s a long way to go yet. The surprising thing is that this isn’t really a technical question. It’s a cultural issue, and MTConnect is how we can get people and machines talking a common language.” In fact, MTConnect Version 1.0 is being reviewed by its 18-member MTConnect Technical Advisory Group, which is expected to vote on adopting it as an open standard before the end of the year.
“People have been looking and waiting for this kind of machine data communication for a long time,” adds Warndorf. “Builders and users are tired of all the historical integration problems, lack of interoperability issues and having to recreate software every time they add or upgrade a device. This is why they needed a common data protocol. However, we aren’t forcing users to take on data calculation cycle time or integration labor. MTConnect simply shows data as it is, and then users can add the analysis tools they need.”
For instance, a shop owner with machines and a shop-floor control system can use MTConnect to determine the times it takes to make a part from start to finish, check operating speeds and send alerts or alarms, explains Warndorf. “By adding heat and vibration sensors and coordinating their data with execution information, users can even check their tool paths and monitor whether their machines are operating as expected,” he says. “MTConnect is all about shifting machine data and communications to value-added areas.”
