Proton Energy Systems and Northern Power, both wholly owned subsidiaries of Distributed Energy Systems, were designing and building a hydrogen fueling station to be installed in New York State. The system would generate hydrogen on site from electricity and water using Proton Energy Systems’ H-Series electrolyzer (hydrogen generator). To track hydrogen production and energy consumption, Northern Power would use its own SmartView Monitoring System, which has OPC-based connectivity. Gathering OPC-based data would be handled by the KEPServerEX OPC Server, from Kepware Technologies, based in Portland, Maine. KEPServerEX with Modbus drivers would collect data from a set of power meters and the hydrogen generator, which has a proprietary controller with a Modbus interface.While the hydrogen generator’s controller is generally Modbus compliant, Error and Warning data is stored in binary strings that are not readily accessible from standard Modbus Masters. Northern Power engineers were tasked with finding the best way to bring this non-standard data into the SmartView Monitoring System without spending money to re-engineer the controller’s Modbus interface. They outlined the following requirements for the desired solution: The ability to read proprietary binary string dataDoes not require programming experienceMake the data available through an OPC serverMust be reliable and proven in industrial applicationsCost effective (product price as well as implementation time)Since Northern Power had already standardized on Kepware’s OPC server, the company contacted Kepware for a recommendation. Kepware’s technical support team suggested the User-Configurable (U-CON) driver plug-in for KEPServerEX. The U-CON driver allows users to quickly and easily build custom read & write transactions for nearly any serial or Ethernet device. The resulting transactions become “tags,” or OPC items that are then made available through the KEPServerEX OPC server interface.A Northern Power engineer reviewed sample transaction information that comes with the U-CON installation and within minutes he was able to properly read a binary string from the generator controller. Device diagnostic features made it possible to verify the packets in both directions and develop a working solution to log errors and warnings into the SmartView client. According to Brendan Taylor of Northern Power, “The U-CON solution met our requirements with the new hydrogen fueling station but we were able to easily retrofit an existing monitoring system as well. Having the U-CON connectivity available through our existing KEPServerEX interface was not a requirement, but makes it much easier to maintain and support these systems in the future.” For more information about OPC solutions from Kepware Technologies, visit www.kepware.com.
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