Hitachi HUS157336EL3600 Spindle Start Selection, Drawing No. Sheet No. Revision, K6602906, 17/46

4.3.2 Spindle Start Selection

When multiple disk drives are connected to the same power supply and turned on simultaneously, a large current will be required at power up.

In the above case, it is recommended to turn the motors on one by one at intervals in order to minimize 12V line current.

This can be done according to the following 3 jumper pin configurations in the case of NW drive:

1.If Disable Auto Start mode is set (C3:9-10 installed);

(1)Use a spindle start command for each drive, issuing it to the next drive after receiving the previous drive’s Ready condition.

or

(2)Use the spindle start command for each drive, issuing it at intervals of more than 10 seconds.

2.If Enable Auto Start mode is set (C3:9-10 removed) and Spindle Start at Power On is set (C3:13-14 removed);

Manually power on drives at intervals of more than 10 seconds.

3.If Enable Auto Start mode is set (C3:9-10 removed) and Delayed Start is set (C3:13- 14 installed);

Upon power on condition, the drives will automatically spin up in 10 second intervals according to their SCSI ID. (The drive with the lowest SCSI ID will start first.)

In the case that their SCSI ID are more than 7, the drives will automatically spin up in 10 second intervals according to the numbers of (SCSI ID minus 8).

Note 1 The Delayed Start setting and the Auto Start setting can be done by commands from host via SCSI bus connector (C1) in the case of NC drive.

Drawing No. Sheet No. Revision 5
K6602906	17/46	2003/6/12