OPC Standard Provides Value to Big and Small Plants

In July of 2005, the Martinsburg Municipality in Pennsylvania agreed to install trending software packages from Canary Labs, based in Martinsburg, to monitor the municipal wastewater plant. This was a small plant that monitored about 75 points from Rockwell Automation’s Allen-Bradley brand programmable logic controllers (PLCs) and used a simple human-machine interface to show the real-time values of the system. Canary installed an OPC server from Kepware to connect to the A-B PLC. A connection was also made from a strip chart recorder that measured flow to the PLC, making the data available over a network to the Canary Trend Historian. Canary Trend Link was installed to allow the setup of trend charts and ad hoc inquiries to view the history of the data.

The initial reaction from Gary Hooder, plant operator, was “Canary trending is overkill and I really don’t believe this will do much for us.” Within a few days after data collection began, Hooder started asking questions about the data and what was happening in his process. At this time, the Canary Trend Calc program was installed to provide calculated flow averages for a better long-term picture of the results of the plant. After a few weeks, Hooder started to better understand events that were happening in the plant.

Says Hooder, “Before the Canary software was available, I could only see what was happening at that instant. I did not have the information that led up to an event. The Canary trending allows me to go back in time and see what happened over the past minutes, hours, overnight or over a weekend.” Hooder continues, “Also, when my trend charts show that the data from the system is not typical, I can quickly determine the problem and resolve it before it becomes a major problem.

“I now have historical information to help understand complex processes and determine better ways to increase the efficiency of the plant and the quality of the effluent that is released into the stream at the end of the process.”

Another benefit of the Canary software is the ability to manually enter data from the daily lab reports into the Trend Historian. This allows the monthly reports to be automated and generated within seconds within the Microsoft Excel program. It used to take hours at the end of each month to calculate and generate the required reports for the state environmental agency. The facility now can run reports at any time to see where it stands against its overall monthly limits.

The Trend Historian is replicated in real time to another historian located at the Canary Office for backup purposes. This backup Trend Historian also provides data to a Web server via the OPC-Historical Data Access (HDA) interface and allows the plant operators to “check in” on the plant during off hours or over weekends via Canary’ s Trend Web product, without leaving their homes.

Hooder says now, “I would not want to run this plant without the Canary software, and I depend on it every day. The software is worth more than gold to me. I am recommending it to neighboring municipalities.”

For more information about historical trending solutions from Canary Labs, visitwww.canarylabs.com.