Step 5: Set Termination - LSI MegaRAID SCSI 320-2 RAID Controller Series 518 Hardware Manual

6.2.4.6 J17/J18 SCSI Bus Termination Power
6.2.5

Step 5: Set Termination

6.2.5.1 SCSI Termination
6.2.5.2 Terminating Internal SCSI Disk Arrays
6-8
J17 and J18 are 2-pin jumpers that control the termination power setting
for channel 0 and channel 1, respectively. Leave both jumpers at the
default setting (jumper installed on pins 1 and 2) to allow the PCI bus to
provide termination power. (When the jumpers are removed, the SCSI
bus provides termination power.)
Each MegaRAID SCSI channel can be individually configured for
termination enable mode by setting the J4 and J5 jumpers. You must
terminate the SCSI bus properly. Set termination at both ends of the
SCSI cable. The SCSI bus is an electrical transmission line and must be
terminated properly to minimize reflections and losses.
For a disk array, set SCSI bus termination so that removing or adding a
SCSI device does not disturb termination. An easy way to do this is to
connect the card to one end of the SCSI cable and to connect a
terminator module at the other end of the cable. The connectors between
the two ends can connect SCSI devices. Disable termination on the SCSI
devices. See the manual for each SCSI device to disable termination.
You can let the card automatically provide SCSI termination at one end
of the SCSI bus. You can terminate the other end of the SCSI bus by
attaching an external SCSI terminator module to the end of the cable or
by attaching a SCSI device that internally terminates the SCSI bus at the
end of the SCSI channel.
Use standard external SCSI terminators on a SCSI channel operating at
10 Mbytes/s or higher synchronous data transfer.
Set the termination so that SCSI termination and termination power are
intact when any hard drive is removed from a SCSI channel, as shown
in Figure 6.3. Also, jumpers J4 and J5 should always be set to allow the
termination to be controlled by software. (See
Termination Enable," page
Hardware Installation
Copyright © 2002 by LSI Logic Corporation. All rights reserved.
6-6.)
Section 6.2.4.3, "J4/J5