40 Megabit/s digital data recorders uses DLT technology

Citation

(1998), "40 Megabit/s digital data recorders uses DLT technology", Aircraft Engineering and Aerospace Technology, Vol. 70 No. 1. https://doi.org/10.1108/aeat.1998.12770aad.006

40 Megabit/s digital data recorders uses DLT technology

40 Megabit/s digital data recorders uses DLT technology

Avalon Electronics Ltd (Shepton Mallet, Somerset) has launched a new series of high capacity data recorders based on DLT (digital linear tape) cassette technology. Already a major supplier of helical scan S-VHS recorders for analogue and digital data capture, the company is one of the first to adapt the DLT system for use in aerospace, intelligence gathering and high speed data communications applications.

Developed originally as a low cost mass storage peripheral for PC and workstations, the multi-track DLT linear format offers a number of important advantages over S-VHS for real time data capture. Sustained data transfer rates anywhere between zero and either 12 Mbits/s or 40 Mbits/s can be accommodated depending on the model selected. (The highest data rate available on Avalon's S-VHS range is 8 Mbits/s.) DLT cassettes also store more data; either 160 Gigabits (20 GB) or 280 Gigabits (35 GB) of formatted data compared to the 86 Gigabit (10.8 GB) capacity of a typical S-VHS cassette.

Initially, Avalon will offer a family of five digital recorders based on the 12 Mbit/s tape drive while 40 Mbit/s versions are planned for release before the end of the third quarter of 1997. Designated Series AE6100HW the new range will record between one and eight separate serial bit streams in NRZ TTL, ECL or MIL-STD-1553 format with error rates better than 1 in 10¹⁴. Data can be output either in the same format as it was recorded or via an optional SCSI-2 Replay Interface for immediate computer analysis. The system architecture allows a number of recorders to operate in parallel without the need for sophisticated resynchronisation techniques. For example, five 40 Mbitls units can operate logically as a single inexpensive 200 Mbit/s data acquisition system.

For real time telecommunications applications, companion models in the AE5400 and AE5500 Series are equipped with CCITT compatible mux/demuxes to record many hours of E1, E2 or E3 or T1 and T2 (E1 HDB3, E2 HDB3 G742, E3 G715, T1 B8ZS, T2 G743) encoded data continuously. Input data is "Positively Justified" to preclude the possibility of data corruption which typically occurs when data of this type is re-synchronised to a common exchange clock.

ISDN, HDSL and other in-stream data formats are all transparent to the recorder.

Avalon's new 40 Megabit/sec AE6100HW cassette data recorder stores 280 Gigabits on a single DLT cassette

The new DLT-based systems, including record & replay electronics, power supplies and environmental control measure only 176(h) × 220(w) × 500(d) mm (6.9 × 8.8 × 20.0 in), allowing two units to be installed side by side in a standard 19 inch rack.

For the future, a range of multi-channel analogue/digital "front-ends" are planned allowing users of ageing open-reel IRIG recorders an easy and low risk migration path to the new DLT technology.

All systems are specified for > 12,500 hours MTBF and carry a 5,000 hr 1/3 year warranty.

Details from Avalon Electronics Ltd, Langhorne Park House, High Street, Shepton Mallet, BA4 5AQ. Tel: +44 (0)1749 345266; Fax: +44 (0)1749 345267.