LSI Series 518 6.2.5Step 5: Set Termination

6.2.4.6J17/J18 SCSI Bus Termination Power

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.)

6.2.5Step 5: Set Termination

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.

6.2.5.1SCSI 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.

6.2.5.2Terminating Internal SCSI Disk Arrays

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 Section 6.2.4.3, “J4/J5 Termination Enable,” page 6-6.)

6-8	Hardware Installation