• The Need for Standardized Performance Characteristics for Digital Strip Chart Recorders

      Smith, Grant M.; Gaskill, Dave; Astro-Med, Inc. (International Foundation for Telemetering, 1988-10)
      Digital-based linear-array chart recorders are replacing conventional stylus recorders in telemetry data stations everywhere. They offer advantages in virtually all respects, and are becoming indispensable. But because of the completely different writing method and technology employed, it is difficult to make completely analogous performance comparisons between analog and digital chart recorders. This has led to some confusion when replacing aging stylus recorders is contemplated. Objectives: Establish a set of universal, standardized performance characteristics for digital chart recorders. Introduce appropriate terminology, allowing valid, repeatable comparison of old and new systems.
    • Telemetry Chart Recording Via Direct Digital Link

      Smith, Grant M.; Alexander, James H.; Astro-Med, Inc. (International Foundation for Telemetering, 1988-10)
      Mission safety and cost-efficiency concerns have resulted in a resurgence of interest in real-time strip chart recorders. But conventional recorder technologies require inordinate maintenance and daily calibration. Attempts at strip chart emulation involving costly dedicated microcomputers and CRT's have failed, because the chart itself is not real-time, a basic requirement. The concept of an inexpensive, direct digital link to a telemetry processing computer (VAX, e.g.) is discussed. A thorough examination of real-time monitoring of critical, non-repeatable data is presented. Objectives: An automated, turn-key telemetry data system. Reduce the routine maintenance required by conventional recording systems; eliminate the need for digital-to-analog converters (DAC's); and improve the efficiency of range personnel and the integrity of recorded data.