PLC PROCESS WEIGHING CONTROL-SYSTEM DESIGN

Designing a fast and accurate process weighing control system starts with an understanding of what affects weighing speed and accuracy. Selection of weighing system components, installation, calibration, and configuration affect both speed and accuracy, but often overlooked are the errors introduced by the method in which the host programmable controller uses the weight data. This article presents contributors to weighing system errors and how to avoid them, recent advancements in weighing and programmable controller interface technology, scale/programmable controller interfaces with their advantages and disadvantages, and examples of filling, dispensing, batching and blending with optimum selection of components and control strategy.