SCSI bus transmission problems and solutions

The most common cause of SCSI operational problems is induced noise and signal reflections caused by poorly constructed cables. For reliable system performance, SCSI cables must meet ANSI X3T10 standards, which define both electrical and physical parameters.

Paralan SCSI Quiet Cable™ is the solution to cable problems, with 100% testing, full ANSI spec compliance, and shielded connector assemblies.

For a fast but thorough check on any SCSI cable, check out Paralan's Hand-Held SCSI Cable Tester, Model ST1000, inexpensive and simple to use, all tests are run from one end of the cable, or the benchtop Model, SCSI Cable Tester Model ST123. In seconds, it checks any SCSI cable for twisted pair integrity, pin-to-pin continuity, shorts, opens, etc.

For a more detailed analysis of cable problems, see the technical note The Case for Quiet Cable.

SCSI buses are often disrupted when devices are removed or replaced. Paralan's SCSI Isolating RegeneratoR™s allow devices connected to one port of a RegeneratoR™ to be unaffected by changes on the other port. For a discussion of SCSI Isolating RegeneratoR™s and other expander techniques, see Marc Brooks' article for Computer Technology Review, The Case for SCSI Expanders.

Terminations may be present on the bus, but without power. Paralan's Auto Sense™ assures a termination at the opposite end from a SCSI Converter or SCSI RegeneratoR™ will have the proper +5 V power applied.

Paralan can match your SCSI needs with custom SCSI components, modifications to standard Paralan products, or even with custom systems! Paralan is ready to meet your exact requirements by applying our SCSI-savvy engineering - from SASI through Ultra320.