By Aaron Hand
When the Eurotherm nanodac recorder/controller was launched just over a year ago, not only was it revolutionary in bringing recorder and control functionality together in one small device, but Invensys Operations Management also made sure it could easily integrate with the other products in its toolset as well. Now the company has linked it even more closely with the InFusion Enterprise Control System, including connectivity to the Wonderware Historian. Updates also include greater storage flexibility for longer local data archiving and "store and forward" data retrieval.
With 50 MB of flash memory for data storage, nanodac can record up to 38 parameters at any given time, storing months of data if necessary. Of the 38 channels, up to eight physical universal inputs are accepted at the back of the device. The remaining 30 inputs are available as virtual channels, notes Peter Sherwin, marketing manager for Invensys Eurotherm, North America.
The "store and forward" capability means the nanodac can store data itself, but also pass it up to the historian. If there were a break in communication because of a power failure, for example, nanodac would continue to capture and store information. "The historian wouldn't be picking up real-time data, but nanodac would be keeping it on the device," Sherwin explains. "Then when the power is restored, the historian would grab that data from nanodac. It takes a couple minutes to do the process, but there's no user intervention needed."
Without a local collection and retention device, failing communications can mean the risk of important data loss, notes Bob Postlethwaite, global marketing director for Invensys Operations Management. "For a food and beverage or pharmaceutical manufacturer, for example, that could lead to a batch being quarantined or even scrapped," he says, adding that nanodac's connection to the Wonderware Historian component ensures that data retrieval is automatically implemented whenever needed.
The recorder/controller works well as a local historian with third-party equipment, but also can be used as a stand-alone device. With an on-screen help system and remote viewing functionality, nanodac lets plant-floor operators and supervisors monitor and discuss the health of their process from virtually anywhere, enabling them to use the real-time operating information to make better operating and business decisions.
How much data can be held in nanodac's 50 MB of memory depends, of course, on the application. Heat treatment applications, for example, typically sample every one or two minutes, Sherwin notes. "For that, for maybe a handful of parameters, literally years worth of data can be stored in the flash memory," he says. "If you have very fast processes or more parameters, still you've got days worth of data that can be stored."
In addition to its data acquisition capability, the Eurotherm nanodac instrument also has an option to provide two high-stability PID control loops with the Eurotherm Autotune facility.
Not insignificantly, the nanodac is small, Sherwin notes. It's based on a quarter-DIN size, just 192 mm square, putting recording and control into one small instrument. "This allows an electrical engineer to design his control panel to be in as small a space as possible," Sherwin notes, pointing out also the vivid 3.5 in. TFT display. "The ability to communicate data to the operator becomes very easy."