NT, PC, PLC data blend to improve lockset assembly
Human or electronic, happy marriages are based on good communications and input. One blissful partnership recently increased quality and flexibility at Kwikset Corp.'s lockset assembly plant (Waynesboro, Ga.).The company joined its 1960s-era manufacturing methods with Rockwell Software data acquisition software and three Allen-Bradley SoftLogix 5 controllers, both from Rockwell Automation...
Human or electronic, happy marriages are based on good communications and input. One blissful partnership recently increased quality and flexibility at Kwikset Corp.'s lockset assembly plant (Waynesboro, Ga.).
The company joined its 1960s-era manufacturing methods with Rockwell Software data acquisition software and three Allen-Bradley SoftLogix 5 controllers, both from Rockwell Automation (Milwaukee, Wis.). These allow access to real-time data from Kwikset's plant and office locations. In 1997, when the Waynesboro plant started production, its controls included more than 70 Allen-Bradley PLCs linked by three network lines. Shift supervisors manually gathered trend data that wasn't real-time or up-to-date.
After evaluating the plant's specific needs, Kwikset's staffers chose to base their self-named OPTIMUS (Online Performance Tracking and IMprovement Information System) on Microsoft Windows NT. Five priority data pieces sought from the new system were: parts in, parts out, uptime, downtime, and percentage efficiency.
Accessing existing data
To store and make all plant data available, as well as protect the controller network and prevent bandwidth overcrowding, Kwikset's engineers buffered information from the plant's 70 controllers in a robust system that preserved network capacity for other functions. Designed to serve as supervisors, SoftLogix 5 controllers were integrated into Kwikset's overall system by loading them onto PCs with network interface cards with redundant backups.
SoftLogix engines handle plant floor controller polling and supply resulting data to a Microsoft SQL Server database using Rockwell Software's RSSql transaction manager and RSView32 human-machine interface software. Data requests go through the system's information level, rather than the PLC's gateway, which could clog the network. RSSql communicates via Ethernet between the engines and SQL Server database. This means data can be recorded only when needed, which reduces database size and increases inquiry speed. That reduced Kwikset's per day data gathering from tens of thousands of records to about 200 records.
"This architecture lightens the load on the PLCs and three established trunk lines so supervisory data requests are made where they should be—on the information level," says Leslie Cooper, Kwikset's plant control engineer.
After its first year in production, Kwikset's new control system broke even and made up first-half operating losses with increased second-half productivity. Kwikset says it will roll out OPTIMUS at its other facilities soon. The company also plans to expand access to real-time data to about 70 points throughout its Waynesboro plant. "We'll be considering a plant expansion at some point down the road, and all we have to do is add another network gateway to link the new area into our system," says Chris Werner, Kwikset's plant manager.
For more information, visit www.controleng.com/info .