Terminating the SCSI bus

Terminating a SCSI bus preserves high transition speeds, and when properly placed will clean up the signal along the entire length of the line and provides a reasonable degree of noise immunity. The termination of a SCSI bus is required for the bus to work properly.

• Use only highest quality of SCSI cabling. Flat cables are much better than round ones. Do not make your own cables, and replace injured cables.  
• Do not use "Stubs" in the chain, just one long cable is the best.  
• Use "Active Terminators" at both ends of the chain as an "Active Terminator" vary its resistance to provide the optimum value. The Axis cd servers are using Active Termination but most of the internal terminators on the drives are passive. If so, use a standalone active terminator in the opposite end of the cd server! Note that you must use the internal termination in the StorPoint, as it's not possible to turn it off. The "SCSITermination" parameter in the CONFIG.INI file doesn't work! (In the 850/950 it does.)  
• At least one unit on the chain must supply power to the termination resistors. StorPoint supplies "Termination Power" at pin 26, (TERMPWR) the 850 does NOT. Leave Termination Power ON at all drives! Some drives have a switch called TERM and it sometimes means "Termination power" and not "Termination".  
• The cd servers are much more sensitive than a normal SCSI card, regarding termination errors. The tower was working OK on a PC server, but when connecting it to the StorPoint it doesn't work. The chain has been improperly terminated the whole time but still worked fine. 

Note that a badly terminated chain can make the whole CD server crash!