SCSI Converters and Extenders
SE-HVD SCSI converters and extenders enable you to interconnect single-ended and differential interface. Convert between Single-ended SCSI and HVD SCSI devices Both 8-bit and 16-bit Models Extend SCSI Bus Length

The first implementation of SCSI was single-ended. Differential (HVD) SCSI was developed for improved noise immunity, increased drive stability and the longer attainable cable lengths.

Paralan SCSI converters make communication between both types of devices possible. Hardware and software remain the same: the converter is transparent to all devices. Plug your single-ended cable into one end of the converter and the differential (HVD) cable into the other end. All SCSI devices will be available.

All Paralan SCSI Converters conform to the full SCSI ANSI standard. This includes managing the arbitration and disconnect/reconnect features of the latest systems, down to the SASI communications of earlier systems. They manage any possible signal conflicts such that they remain transparent to both HVD and single-ended devices.

SCSI converter/extender models are available for both wide (16-bit) or narrow (8-bit); and in stand-alone or board-level versions.

Paralan introduced the industry's first Fast (10 Mbyte/sec) single/differential (HVD) SCSI converter in 1992. These new models, using our own ASIC, are Ultra SCSI compatible: 20 Mbyte/sec for 8-bit (narrow) and 40 Mbyte/sec for 16-bit (wide) SCSI.

Narrow and wide devices may be placed in the same system. Call Paralan for details.

Extend Total Cable Length

By using two converters in series an extension up to 140 feet (45 m) is obtainable. See "Operation as a SCSI Extender," below, and the transmission length table on the SCSI extension page.

Handle Bus Noise, Termination Problems

Auto Sense™ detects correct termination power. All models have internal terminations which may be disabled if the converter is not placed at the end of the bus.

Operation as a Single-ended/HVD SCSI Converter

Since SCSI is a bidirectional bus, a single converter is used to interconnect single-ended SCSI IDs with HVD SCSI IDs. Place the converter within 19 feet (6 m), or 10 feet (3 m) for fast SCSI, or 5 feet (1.5 m) for Ultra SCSI, of the single-ended SCSI port. Up to 82 feet (25 m) of cable may be placed between the converter and HVD port, or 87 to 100 feet (26.5-31 m) overall. Paralan is the first to produce SCSI converters that enable the maximum SCSI cable length on both ends, even through Ultra speeds.

SCSI Extension

Single ended: Two Paralan converters can extend the single-ended SCSI bus up to 200 feet (60 m). Place each converter within 19 feet (6 m), or 10 feet (3 m) for fast SCSI, or 5 feet (1.5 m) for Ultra SCSI, of the two single-ended SCSI ports. Then connect up to 120 feet (37 m) of differential SCSI cable between them.

Differential (HVD): Two Paralan converters can extend the HVD SCSI bus up to 174 feet (53 m). Connect up to 82 feet (25 m) of differential SCSI cable to each converter. Then connect up to 10 feet (3 m) of single-ended cable between them. For HVD SCSI extension, the SCSI RegeneratoR™s (SIR-Dx series) are usually a better choice for distances up to 280 feet (85 m).

Examples:

PDF version of this data sheet.

Ordering Guide:

Specifications For SD10D/SD11D SD16B/SD17C:

Environmental Relative Humidity: 0-95% non-condensing Operating Temperature: 0-50°C Power Requirements SD10D, SD16B: 115/220 V ac, auto select, 50-60 Hz, 10 Watts SD11D: +5 V dc ±5% @ 1 A max. SD17C: +5 V dc ±5% @ 1.5 A max. EMI/RFI Meets FCC Class A, CE Communication Parallel Transmission Rate (sustained): SD10D, SD11D: up to 20 Mbytes/sec Ultra SCSI SD16B, SD17C: up to 40 Mbytes/sec Ultra SCSI Protocols: ANSI X3T10 SCSI standard Safety Approvals UL, CSA, TUV/VDE, CE Weight: SD10D, approx. 1.5 lb. (0.7 kg); shipping weight 4 lb. (1.8 kg) SD11D: SCSI Alt. 1 (0.1" pitch header) SD16B: approx. 2 lb. (1 kg); shipping weight 4 lb. Warranty Two year limited warranty

SCSI Connections SD10D: SCSI-2 (Alt. 2-A cable, Centronics type) SD11D: SCSI Alt. 1 (0.1" pitch header) SD16B, SD17C: SCSI-3 68-pin High-Density female "P" Connector Dimensions SD10D: 4.1"W x 6.9"D x 1.6"H (104 x 175 x 41 mm) SD16B: 4.1"W x 7.5"D x 2.5"H (104 x 190 x 64 mm) SD11D, SD17C (board dimensions): 5.750" W x 3.880"H (146.0 x 98.5 mm).