Low-Cost PC-Based Telemetry Data-Reduction System

The Solar Energy Research Institute's (SERI) Wind Research Branch is using Pulse Code Modulation (PCM) telemetry data-acquisition systems to study horizontal-axis wind turbines. PCM telemetry systems are used in test installations that require accurate multiple-channel measurements taken from a variety of different locations. SERI has found them ideal for use in tests requiring concurrentacquisition of data from multiple wind turbines and meteorological towers in wind parks. SERI has developed a low-cost PC-based PCM telemetry datareduction system to facilitate quick, in-the-field multiple-channel data analysis. Called the 'PC-PCM System,' it consists of two basic components. First. AT-compatible hardware boards are used for decoding and combining PCM data streams. Up to fourhardware boards can be installed in a single PC, which provides the capability to combine data from four PCM streams directly to PC disk or memory. Each stream can have up to 62 data channels. Second, a software package written for the DOS operating system was developed to simplify data-acquisition control and management. The software provides a quick, easy-to-use interface between the PC andPCM data streams. Called the 'QuickLook Data Management Program,' it is a comprehensive menu-driven package used to organize, acquire, process, and display information from incoming PCM data streams. This paper describes both hardware and software aspects of the SERI PC-PCM system, concentratmg on features that make it useful in an experiment test environment to quickly examine and verifyincoming data. Also discussed are problems and techniques associated with PC-based telemetry data acquisition, processing, and real-time display.