Advantech PCA-6185 user manual SCSI IDs

7.3 SCSI IDs

Each device attached to the SCSI bus, as well as the SCSI controller itself, must be assigned a unique SCSI ID number from 0 to 15. A SCSI ID uniquely identifies each SCSI device on the SCSI bus and determines priority when two or more devices are trying to use the SCSI bus at the same time.

Refer o the device’s documentation to set the SCSI ID. Here are some general guidelines for SCSI IDs:

•For internal SCSI devices, the SCSI ID usually is set by configur- ing a jumper on the device.

•For external SCSI devices, the SCSI ID usually is set with a swetch on the back of the device.

•SCSI ID numbers don’t have to sequential, as long as the SCSI con- troller and each device has a different number.

•For example, you can have an internal SCSI device with ID 0, and an external SCSI device with ID 6.

•SCSI ID 7 has the highest priority on the SCSI bus. The priority of the remianing IDs, in descending order, is 6 to 0, then 15 to 8.

•The on-boards SCSI interface is preset to SCSI ID 7 and should not be changed. This gives it the highest priority on the SCSI bus.

•Most internal SCSI hard disk drives come from the factory pre-set to SCSI ID 0.

•If you have 8-bit (or Narrow) SCSI deveices, they must use SCSI IDs 0, 1, 2, 3, 4, 5, or 6. SCSI ID 0 is recommended for the first SCSI hard disk drive.

•If you are booting your computer from a SCSI hards disk drive con- nected to the SCSI bus, the Boot SCSI ID setting in the

SCSISelect utility must correspond to the SCSI ID of the deveice from which you are booting. By default, the Boot SCSI ID is set to 0. We recommend that you do not change this setting.

•In Windows© 95/98, you can use the Device Manager to determine which SCSI ID is assigned to each installed SCSI device.

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