International Telemetering Conference Proceedings / October 17-20, 1988 / Riviera Hotel, Las Vegas, Nevada / 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.

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / The times that we live in offers the most advanced pace of technology development ever known to the world, and it is getting faster. A large part of commercial computer technology development is based on increased size and decreased cost of memory devices, from which the instrumentation community can derive great benefit through the development of solid state systems. The procurement cost of new solid state systems utilizing increased memory capability makes the temptation to move to this technology unavoidable. There are, however, some issues that need to be discussed which go beyond procurement costs and involve operational and life cycle considerations.

International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / On reviewing current PCM on-board data acquisition systems design is not very uncommon to find lots of useful signals being generated together with the PCM stream, such as bit clocks, word clocks, minor and major frame pulses. The purpose of this paper is to demonstrate a conceptual design of a digital recording device that takes advantage of these signals to collect data directly into a computer compatible disk file. Such device can eliminate the need of further PCM signal processing after the test and speed up the conversion process of pure digital sampling values into floating point numbers.

International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / With the introduction of digital data recorders new ways of data processing have been developed. The three most important improvements are discussed in this paper: A) By processing PCM Data from a digital recorder by using the SCSI-Interface our ground station has developed software to detect the synchronization pattern of the PCM data and then perform software frame decommutation. Many advantages will be found with this method. B) New digital recorders already use the CCSDS Standard as the internal recording format. Once this technique is implemented in our ground station’s software and becomes part of our software engineering team’s general know-how, the switch to CCSDS telemetry in the future will require no quantum leap in effort. C) Digital recorders offer a very new application: Writing data to a digital tape in the recorder’s own format, allows the replay of data using the recorder’s interfaces; i.e. writing vibration data from the host system to tape, using the analog format of the digital recorder, allows the analysis of the data either in analog form, using the analog interface of the recorder, or in digital form.

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / Today’s telemetry environment is becoming increasingly digital. Highly reliable and relatively inexpensive digital recorders readily available, and most telemetry facilities are migrating away from the older analog recorders which are difficult to calibrate and expensive to maintain. Unfortunately, most site managers find they still have one or more “legacy” signals (such as FM-FM, PAM, and pre-detect PCM) that still require analog recording. To exclusively use digital recorders the TM site must integrate some device to convert the analog signals to digital format before recording. Until recently, the TM site managers had very few options short of building custom equipment to convert and capture the legacy signals. One solution available from Racal (for their Storeplex digital recorder) is to purchase their Analog Record/Play Signal Module. Unfortunately, their module uses a 16-bit Sigma-Delta converter and has a maximum bandwidth of 45.5 KHz, which is woefully inadequate for many analog signals. Other manufacturers offer similar solutions with similar bandwidth restrictions. Another solution is to purchase a multiplexor “front-end” which is capable of mixing multiple signal types (both digital and analog) on to the recorder’s serial-digital data stream. This option can provide higher analog bandwidths, but represents a significant investment (greater than $100K and often more than the recorder itself). This paper discusses the conceptualization, design, and performance of a unit to fill the gap between the low-bandwidth analog channel module and the high-end signal multiplexors. We will discuss how high-speed field-programmable gate arrays (FPGAs) can be configured to provide a low-cost interface between the digital recorder and the analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) to capture and playback the analog signals. Our design focuses on achieving the maximum possible bandwidth for each analog signal while ensuring that IRIG-A or IRIG-B timecode are recorded simultaneously (so the analog signals can be later synchronized with their digital counterparts). We have found that such a solution permits multiple analog signals from 400 KHz up to 3 MHz to be easily and inexpensively recorded on the current generation of digital recorders. Our conclusions show that such a device can permit most telemetry sites to transition completely to more reliable, cheaper, and easier-to-maintain digital recorders.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Space and Missile Systems Center at Vandenberg AFB has integrated ID-1 high bit rate helical scan digital recorders into the ground based and mobile telemetry receiving and processing facilities. The systems are used for recording higher bit rates than those available with the current IRIG standard longitudinal wideband and double density instrumentation magnetic tape recorder/reproducers. In addition to the 400 Mbps digital recorders, the systems consist of high-speed multiplexer/ demultiplexers and multi-channel bit synchronizers for recording numerous telemetry data links and sources on a single recorder. This paper describes the system configurations and compares recording capabilities with those of the previous generation instrumentation magnetic tape recorder/reproducers.

International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The purpose of this paper is to describe the development of a very high-speed instrumentation and digital data recording system. The system converts multiple asynchronous analog signals to digital data, forms the data into packets, transmits the packets across fiber-optic lines and routes the data packets to destinations such as high speed recorders, hard disks, Ethernet, and data processing. This system is capable of collecting approximately one hundred megabytes per second of filtered packetized data. The significant system features are its design methodology, system configuration, decoupled interfaces, data as packets, the use of RACEway data and VME control buses, distributed processing on mixedvendor PowerPCs, real-time resource management objects, and an extendible and flexible configuration.