Despite advances in modern physics, you just can’t be in two places at once. In the case of the San Francisco Water Department, sometimes operators must leave the control room to attend to tasks such as calibrating instruments or washing filters. This means that there may be no one in the control room to watch the control system display for alarms.
Dee Cutino, facility superintendent at the San Francisco Water Department (SFWD), purchased a tablet personal computer (PC) built specifically for industrial applications with built-in wireless networking in order to provide operators with data for decision-making while they are on the move away from the control room. “The automation system includes programmable logic controllers with input/output blocks and an industrial computer with system operations software,” says Cutino. “We use the computer to start or stop pumps, change chemical feeds and display alarms. Before I invested in the Wonderware tablet PC, I needed duplicate operators at the facility—one inside to watch the system while the other was out doing the chores.”
Just like the host computer, the tablet PC uses InTouch software, supplied by Wonderware, an Invensys company based in Lake Forest, Calif. With the tablet, the operator can see exactly what is displayed on the main computer while outside performing other duties in the facility. The computer uses IEEE 802.11 wireless Ethernet, known as WiFi, to communicate to the host. The tablet uses pen-based data input.
The local Wonderware integrator, San Francisco-based EandM, sent a representative to work with SFWD information technology (IT) professionals to install antennas where needed to assure coverage throughout the facility and to minimize latencies. Cutino says, “The tablet was easy to set up, and since the screens are identical to the host computer, there was no real training involved. The operators have become so attached to their tablet that during a recent AWWA (American Water Works Association) tour of the facility, the operator didn’t want to give it up to the distributor sales person to demonstrate. The only problem we’ve had so far is that we had to replace the pen once. It’s pretty rugged, which is good, since operators can be kind of rough with them. It’s easy to carry with a shoulder strap plus a handle. Another facility in the district has seen it and bought one. There is only one operator at the facility, so if he is out on maintenance, there is no one to watch for alarms. This will solve the problem.”
More than toys
Adds Dave Gardner, personal computer product manager at Wonderware, “Sales of tablet PCs have taken off as companies have adopted wireless Ethernet as a communications medium. Wonderware set up developers and quality assurance people to work with wireless adaptors in a lab to replicate field conditions and develop a robust wireless mobile computing platform. There may have been an early reluctance to buy these on the part of IT departments—maybe because of the ‘toy factor.’ But as they have seen valuable applications, tablets are seen as a viable industrial product.”
For more information, search keywords “tablet PC” at www.automationworld.com.