WE'VE BEEN WRITING
about systems that will reside on the Internet rather than your plant computer for nearly four years. We also have been waiting all that time for an HMI/SCADA vendor to create one. We have always suspected that one of the “little” HMI vendors would be the first to deploy a web server-based system, because independent software companies are always way out in front of everybody else in the control business.
Finally, we found one. Rather, it found us. Matt Wakefield, Senior Systems Technologist of WPS Energy Services
told CONTROL “Our technology team at WPS Energy Services felt the same frustration that you identify in “Control Software Opens Up, Prices Come Down
,” (Round-Up, Dec. '04, p53) of having to pay $3,000–$5,000 for a seat license on an HMI.”
WPS Energy Services is an energy services company, not an HMI/SCADA software vendor. They sell electricity and natural gas to industrial customers in the Northeast quadrant of the U.S. and adjacent portions of Canada.
“As our energy business grew and we acquired generating assets across the country, we found each plant had different DCS/HMI systems,” says Wakefield. “Our Applied Technology Group had the task of integrating real-time process information into our corporate 24-hour Operations Center in Green Bay, Wis. Every site had its own solution and it was going to cost us up to $50,000 per site to acquire the data we needed using the native HMI software.”
To eliminate the problem of seat charges for additional HMI terminals at the sites, and to acquire the data needed at its corporate headquartersin Green Bay, WPS Energy developed its own web-based data acquisition and HMI system. What they wound up with was a product that is applicable across the process control industry, and they beat all the conventional HMI/SCADA vendors to market. Including the other little guys.
“We developed a number of interfaces for OPC, DDE and Modbus and ported them to a web server,” explains Wakefield. “For the last two years we have refined our solution. In 2004, we migrated our solution to an embedded web server and turned it into a standalone product: 'eMiner,' as in Energy Miner. We continue to use it internally as well as sell it to our industrial customers as a low-cost energy and process management tool that gives them real-time and historical data, license free, via a web browser.”
Essentially, the system uses standard data acquisition (DAQ) hardware and software at the plant site to gather real-time information, such as flow, temperature, level and pressure. Suitable DAQ equipment includes energy and power meters, Advantech ADAM DAQ modules, Modbus devices, and any hardware or software with an OPC or DDE interface. All connect via the Internet or plant networks to an eMiner server in the customer’s plant.
At the server, the data is processed, stored, archived, and made available to subscribing customers via standard web browsers over the plant networks. “eMiner's web-server puts the data on a web-page HMI screen which is available to everyone who is on the customer's network,” says Wakefield.
Usually, eMiner is installed behind the customer's firewall and access is restricted to the facility. “Many customers have select employees with secure Virtual Private Network (VPN) access to their network via the Internet,” notes Wakefield. “In those cases, they have access to the data via the Internet.”
Secure remote access can be improved by “pushing” data to WPS Energy’s server, or to a central company remote server located away from the plant. In this case, the local eMiner acts as a data concentrator that gathers up real time information, encrypts it, and ships it off to the server in secure packets. “No DMZ, external IP address or special port forwarding is required, and all data is encrypted,” notes Wakefield. The remote server then produces the web pages which can be securely accessed by anyone with a user name and password using a web browser via Internet.
WPS Energy does this now with its own customers. “With near real-time information from our customers, we can manage natural gas and electric commodities on behalf of the customer, participate in electric demand response programs, and track long-term historical data,” says Wakefield. It is not hard to imagine a process company using the same software to run secure HMI/SCADA systems from a central server.
Perhaps the best part is the lack of seat charges. A base system costs $2,500 with a Modbus TCP interface. Installation, setup and web page design are extra if a prospective customer is not happy with standard wizard- created web pages.
“In most cases, customers want custom web pages that can cost $1,500–$5,000, and some project management costs can be involved,” he says. “But once it’s implemented, everyone has access to the data via a web page, and there are no extra charges for multiple users.”
Current customers include foundries, plastic extrusion plants, power plants, electric substations and paper mills. Most of the applications are related to controlling energy consumption, but WPS Energy is currently working with resellers to bring the product to market outside the energy industry..
Detailed product information is available at the company’s web site www.wpsenergy.com/eMiner