In rebuilding the casting line, foundry personnel wanted to ensure that the new controls avoided problems they had experienced with the old control system. Troubleshooting and programming on the old system were hampered by slow response times due to network congestion. Centralized control required that the entire line be shutdown to download software changes or perform routine maintenance. The main interface to the line was through a massive hardwired annunciator panel. Operators were required to follow a multi-step procedure to startup or shutdown the line.

The foundry called on Synchrony to design, build and commission controls for the rebuilt casting line.

Synchrony first developed a plant-wide architecture for integrating their control and information systems. The plan utilizes Allen-Bradley’s Data-Highway Plus (DH+) networking for integrating existing PLC controls. Ethernet networking is used for integrating new PLC controls and a number of personal computers. Proprietary molding and pouring equipment is integrated using personal computers running Visual Basic applications. An Allen-Bradley ControlLogix Gateway is used as a bridge between the various networks and systems in the plant. Synchrony engineers further optimized the network’s design to minimize overall congestion.

Using this plan, Synchrony, in conjunction with foundry engineers, designed an integrated system for controlling the rebuilt casting line. The new design used Allen-Bradley PLC 5/40E and 5/20E processors and PanelView 1400 and 1000 operator interfaces. Allen-Bradley Flex I/O was used to reduce long runs of control wiring. A personal computer running a Visual Basic application was used to implement a mold tracking application.

Synchrony engineers developed electrical schematics for rebuilding the casting line’s control system. Synchrony also constructed and delivered 7 control panels and a main operator console for the casting line.

The main operator console replaced the old hardwired annunciator panel with three PanelView 1400 touchscreen terminals. The PanelView touchscreens display graphical overviews of the entire process. Color-coded status messages highlight where the source of trouble on the line is located. Operators can zoom into a specific area of the system for more detailed information by simply touching that portion of the overview screen. Maintenance personnel can view individual inputs and outputs on the PanelView touchscreen, reducing downtime spent locating and hooking up a programming terminal.

A Visual Basic application was developed to interface with a proprietary molding machine. This application stores mold data in an Access database and uses this information to send cooling water commands to the casting line’s PLCs. A supervisory PC is under development using Rockwell’s RSSQL software to capture process data for use in quality control and product improvement activities.

Synchrony personnel commissioned the casting line on time and on budget. The new system provides the following benefits:

• Operators can start the casting line with just a few entries on the touchscreen.
• Alarm lamps have been replaced by color-coded status messages on graphical overview screens pinpointing the cause of problems
• Changes to the main console can be performed through software changes to the PanelView terminals. No more rewiring the annunciator panel.
• Common control code shortens the learning time for maintenance and engineering personnel to familiarize themselves with the ladder logic program.
• Through the ControlLogix gateway, maintenance and engineering personnel can monitor, backup and troubleshoot any PLC in the foundry from the comfort of their shop or office.
• Networking bottlenecks have been eliminated
• Decentralized control has eliminated the need to shut the entire line down for software modifications or routine maintenance.
• Allen-Bradley Flex I/O reduced long runs of control wiring and simplifies maintenance by placing the I/O point closer to the equipment being controlled.