Sensors are just as important to Bayer AG’s customer service as its fancy inventory and supply chain management software. From its largest plant in Leverkusen, Germany, the giant chemical and pharmaceutical company relies on radar, ultrasound and pressure sensors to monitor the levels of the remote storage tanks that it maintains at its customers’ plants. Based on reports from these sensors, the plant’s management software not only orders supplies and schedules production to satisfy demand automatically, but it also dispatches trucks to refill its customers’ tanks with the appropriate chemicals as needed.

The ability to provide this service was the result of a project that Bayer had initiated to streamline its supply chain, consolidate deliveries and get closer to its customers. Its backbone is an integrated manufacturing and delivery system designed and built by ATplan GmbH, a German systems integrator based locally in Leverkusen. The success of the project adds Bayer to the growing list of manufacturers learning how to use today’s sensor, transmitter and networking technologies and communications standards to integrate and automate the businesses with real-time information.

To streamline the initial implementation and later upgrades and expansions, ATplan chose interfaces and technologies that would reduce the plant’s dependence on proprietary technology. The sensor interface, for example, was the modular Snap Ethernet I/O from Opto 22, a remote monitoring and networking specialist based in Temecula, Calif. The Ethernet interface connects the sensors to conventional and wireless modems and to the Internet, which in turn link the sensors to Bayer’s enterprise information network. An Oracle database collects the data, puts a time stamp on it, and packages it for the various applications that need it, including Bayer’s SAP supply chain management software.

Integrating sensors requires three components: a sensor interface on the plant floor, some means for transmitting the information, and networking technologies to carry it to the appropriate database or application. “Sensors have been in place for quite a while, but you need some sort of interface [to make it work],” explains David Crump, a spokesman for Opto 22. “So we’re seeing more intermediary hardware [become available] for connecting enterprise databases and SQL (structured query language) servers with the process equipment.” Sometimes one device suffices, and at other times, several are necessary.

“The trend is toward aggregating information and putting intelligence behind it before feeding it to a higher-end application,” adds Mike Prowten, at Lantronix Inc., a vendor of networking devices and services from Irvine, Calif. “Automation companies are connecting equipment that was not normally network-enabled before and are providing easier access to the data and control of that equipment.” The two-step process of making that happen, he says, is putting the sensor information onto the network and pushing the intelligence as far down the hierarchy of devices as possible.

Smart links

Because of the relatively cheap computing power available today, an intermediate device gaining a measure of popularity in the process industry is the programmable automation controller (PAC), which brings together features of a programmable logic controller (PLC) and a personal computer (PC). The combination preserves the reliability and ruggedness of a PLC and adds the open systems computing and communications technology found on a PC. PACs can connect to a variety of sensors, analyze their signals in real time on the factory floor for immediate use there, and upload information to a central database. “One of the primary benefits of using PACs is the communications protocols that enable easy connectivity,” says Rahul Kulkarni, product manager, industrial data acquisition and control, at National Instruments Corp., a manufacturer of PACs based in Austin, Texas.

For example, PACs can recognize smart sensors that have their “personalities” defined according to the relatively new IEEE 1451.4 standard, promulgated by the Institute of Electrical and Electronics Engineers. Manufacturers of this class of sensors encode a set of coefficients describing a sensor in an electrically erasable programmable read-only memory (EEPROM) chip. The PAC can search for these coefficients and read them automatically, much like PCs do with plug-and-play hardware. Consequently, not only is changing sensors simpler than in the past, but keeping them calibrated also is easier.

“Our PACs even can have an embedded Web server in them, so you can transmit data directly in XML (eXtensible Markup Language) and talk directly to an ASP.Net page (provided by a third-party application service provider) via TCP/IP (transmission control protocol/Internet protocol),” says Kulkarni. “It opens up a whole variety of communication protocols that you cannot even imagine with a PLC.”

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