Appendix B
SCSI Termination
B.1
Setting the SCSI Termination
The first and last physical SCSI devices on each end of the SCSI bus must be terminated.
Termination is set automatically through Fast!UTIL (see section A.2.1). The QLA12160 board offers the additional option of terminating with jumpers (see section B.2).
Some cables have multiple connectors for connecting several devices to one of the board’s connectors. If the board uses a connector that is not on either end of the cable, then the board is not at one end of the SCSI bus and you need to change the termination setting.
The following sections describe how to set termination for the QLA12160 board. The text and illustrations describe multiple SCSI devices daisy chained onto a single connector on the board. When daisy chaining narrow and wide SCSI devices, always have a wide SCSI device at the end of the chain.
NOTE: QLogic recommends using external termination in system configurations with multiple initiators that share the same SCSI bus (such as in Microsoft cluster configurations). External termination ensures proper device operation during power cycles. When external termination cannot be provided, terminate all host bus adapters using jumpers (see section B.2).
B.2
Termination (Jumpers) for the QLA12160
The QLA12160 board comes from the factory with jumpers on pins
Moving the jumpers on J5 and J6 on the QLA12160 board manually sets the termination for port one. Moving the jumpers on J7 and J8 on the QLA12160 board manually sets the termination for port two (see figure