Overview
ISO 6068:1985 specifies the recording characteristics and interchange requirements for instrumentation magnetic tape, including telemetry systems. Its purpose is to ensure that information recorded on magnetic tape can be reliably interchanged between different systems by defining tape/reel, recorder/reproducer and recording mode characteristics, plus recommended test procedures. The standard includes informative annexes on testing, tape/reproducer use criteria, PCM guidance and frequency-division multiplexing (FDM) recommendations.
Key topics and requirements
- Tape and reel characteristics: standard tape widths, reel types and physical tolerances for interchangeable instrumentation magnetic tape.
- Tape speeds: definitions of standard, actual and effective tape speeds and guidance on tape-speed correction and flutter compensation.
- Track and head geometry: track configurations, head spacing, head tilt, head polarity, head interchangeability and head-segment/gap characteristics.
- Data azimuth and data scatter: static and dynamic data azimuth definitions, data scatter, and individual track azimuth deviations relevant to signal loss and compatibility.
- Modes of recording: coverage of Direct Recording (DR), Single‑carrier FM, multiple‑carrier FM (FDM), PAM (pulse amplitude modulation), PCM (pulse code modulation), pre-detection recording and timing signal recording - and the modulation patterns used.
- System parameters and tests: record/reproduce parameters, bias and carrier deviation topics, PCM/PAM frame/word structures, bit rate considerations and recommended test procedures (see Annex A and B).
- Annexes A–E: recommended procedures for testing recorder/reproducer systems; tape recorder/reproducer information and use criteria; additional test notes; PCM standards guidance; and FDM use criteria.
Applications and users
ISO 6068 is applicable where reliable interchange of instrumentation or telemetry data recorded on magnetic tape is required:
- Telemetry system designers and integrators ensuring cross‑system data compatibility.
- Magnetic tape recorder/reproducer manufacturers specifying head geometry, track layouts and performance.
- Test laboratories and QA teams implementing the standard test procedures in Annex A–C for acceptance and calibration.
- Data archivists and labs managing long‑term storage and playback of instrumentation recordings.
- Procurement and standards writers who need objective interchange requirements for equipment acquisition.
Related standards
- ISO 6371 - unrecorded instrumentation magnetic tape specifications (referenced)
- ISO 1858, ISO 1860, ISO 3802 - reel and hub specifications for interchange applications
- Annex D of ISO 6068 provides additional PCM standards information and recommendations.
Keywords: ISO 6068, instrumentation magnetic tape, telemetry systems, magnetic tape interchange, recorder/reproducer characteristics, tape speeds, track configurations, PCM, PAM, frequency-division multiplexing, test procedures.