Paralan SCSI 

MS8 / MS9
Narrow Single-ended SCSI Bus Expander

When your Narrow Single-ended (SE) SCSI bus is just a bit too short, there is a simple, economical solution: Paralan's Models MS8 and MS9 SCSI Expanders. A Paralan Expander sends and receives SCSI transmissions at maximum sustained SE SCSI data rate.

No need to modify software or hardware! Does not consume a SCSI ID. Target and initiators may be located on both the A and B sides of the Expander. Just connect your SCSI cables to a Expander and all devices on the bus will be available at an extra bus length. It's as easy as that!

SCSI too short?

To obtain one extra SCSI length, simply select the Expander model appropriate for your installation and plug in your cables. Daisy chaining of two or more Expanders can achieve even longer extension (see drawing below). This configuration with Model MS8 Expanders works well to extend a single-ended bus segment. A full SE cable length can be used on the end segments and up to 40 feet (12 meters) of cable can be placed between the two MS8s to achieve a total distance of 43 feet (13m) to 80 feet (24m) depending on the speed of the SE bus. For a discussion on SCSI Extension see the Extending SCSI page, and the article The Case for SCSI Expanders.

SCSI devices need isolation?

Devices on one side of the Paralan Expander may be disconnected and not affect devices on the other side, as the signals on each side are isolated.

Paralan Expanders -- Not just repeaters! Cable causes timing delays of approximately 1.5 ns per foot of length. When SCSI specified cable length is exceeded, this cable-caused delay would normally cause a system to malfunction. Logic circuitry in Paralan's Expanders manages this delay such that disconnect, reconnect, arbitration and all other SCSI features are not affected. The SCSI signals are regenerated, reshaped, and retransmitted, all transparent to the hardware, the software and the operator. Paralan's exclusive Auto Sense™, standard on all Paralan Expander models, automatically detects correct termination power, solving many initial installation problems.

All Paralan Expanders are compatible with all devices that conform to the ANSI X3T10 standard. They are available either as stand-alone units utilizing wall power (Model MS8), or as board-level units for installation in other equipment (Model MS9).  

For a printable version, please see the PDF of this data sheet.