As part of Amway's controls strategy, the company is beginning to eliminate clipboards and paperwork on its packaging lines by automating data acquisition functions. Such data collection is made possible by a data logging computer adjacent to each packaging line in Amway's personal care plant, tied into the packaging area's PLC network. "There's a lot of paperwork that goes on along the line during a production run," says Jay Mol, electrical engineer at the personal care plant. "The data logger has, for the most part, eliminated all that paperwork." It also permits the data to be easily shared by other departments on the company's local area network (LAN), to which the data logger is attached. Finally, it reduces the exposure to human error that existed when log sheets were filled out by hand and key-punched into a computer. The data logging computers are off-the-shelf PCs (not industrial-hardened) in washdown-grade stainless-steel cabinets. The PCs are running software Amway wrote itself in Microsoft's Visual Basic language. By polling the various PLCs on the packaging line, the computer automatically collects data such as filled bottle count, case count, production speed, and product temperature. Based on the data it collects, the software also computes such statistics as uptime, downtime (although not the specific causes), average production rate, peak rate, scrap rate and a variety of efficiency measurements. All this data is logged by product run, as well as by shift. For some data acquisition, however, the process is still semi-automatic. "A scale and torquer is attached to the data logger," says Mol. "When an operator takes occasional weighments, the data goes right into the system rather than onto a clipboard," he says.
