Manufacturing Process Boosted by Ethernet/IP
Ethernet communications is gaining popularity in industrial controller applications by enabling the instantaneous exchange of information between processing equipment and companies' Ethernet-based management systems. A case in point: EtherNet/IP™ technology used in Watlow's SERIES PD controller is helping Canadian-based Konal Engineering boost efficiency and reduce costs in the manufacturing of its headliner systems for the automobile industry.
Konal Engineering manufactures, among other things, totally automated systems for the production of polyurethane composite headliners for automobile roofs. Konal's headliner manufacturing process works by thermoforming Azdel (polypropylene) and A-surface (polyester or nylon) into headliners after heating to process temperatures - fabric heated to 100-185°C (212-365°F); Azdel to 205-210°C (401-410°F). The multi-layer material machine heats the sheets in an oven where infrared sensors monitor the temperature of the sheets. When proper temperatures are achieved, the materials are bonded together.
Watlow's SERIES PD controllers with embedded EtherNet/IP™ technology provide a convenient, economical method for Konal to set up and view key process variables during the manufacturing process. The SERIES PD controller communicates via EtherNet/IP™ to an Allen-Bradley programmable logic controller (PLC).
Mike Schoger, Konal Engineering's manager of electrical controls, says the key benefit is the company no longer needs to buy a full thermocouple or input module, which typically has eight inputs - six or seven of which would have gone unused. The SERIES PD controller eliminates the need for an analog input module and a thermocouple module because the Watlow controller performs both functions.
"We wind up saving about $400 on each project, and that really adds up over a year," Schoger says. He adds that the SERIES PD with EtherNet/IP™ has data logging features that save additional time and resources for the company.
In 2005, the SERIES PD became the first temperature controller to offer Open DeviceNet™ Vendors Association (ODVA™) EtherNet/IP™ conformance tested communications. SERIES PD controllers offer single or dual loop control, can be DIN-rail mounted, provide up to four control/alarm outputs and up to two digital/current transformer inputs. The SERIES PD also provides a webserver for configuration and operation via a web browser such as Microsoft®'s Internet Explorer, as well as an e-mail client for notifying operators or service personnel of alarms and other conditions.
Watlow product manager, Sean Wilkinson, says EtherNet/IP™ technology is becoming widely accepted due to the speed advantages over lower baud rate protocols, the number of tools available for troubleshooting and optimizing a network, the broad base of competitive vendor support and solution options and the large pool of trained personnel who are familiar with the technology.
Using EtherNet/IP™, specifically yields the advantages of an Ethernet network, including:
-Explicit messaging, which allows devices to be configured via the network. A device can be detected and completely configured automatically in the event a piece of hardware is replaced.
-Implicit messaging, which allows efficient communication of data and instructions from one device to another or from one device to many consumers of data on the network. This minimizes network traffic and allows the speed advantage of Ethernet to be achieved.
-Assurance of interoperability. All devices are tested by ODVA™ and users can expect fewer problems when putting devices from multiple vendors together on a network.
-Integration with other EtherNet/IP™ compliant devices such as PLCs or touch screen human-machine interfaces (HMI).
"Traditionally, performing temperature control in a PLC can be difficult or can interfere with other program functions, so temperature is often controlled separately from the PLC. But in the past due to differences in the supported protocols, getting standalone temperature controllers and PLCs to communicate has been time consuming, costly and difficult," Wilkinson says. He adds that customers prefer temperature controllers outside of the PLC when performance of control loops is important or when the PLC application could be negatively impacted by incorporating thetemperature controller, for example where there is significant motion control.
EtherNet/IP™ technology bridges that gap by allowing for effective and efficient temperature control to be incorporated into the overall control scheme.