HP manual Terminating the A4800A Adapter

Installing the A4800A Adapter

Terminating the A4800A Adapter

Terminating the A4800A Adapter

IMPORTANT

NOTE

The A4800A has no auto-termination setting. Termination must be provided by a physical terminator. When the HBA is at the end of the SCSI bus, the terminator should be installed and secured at either the internal or external connector (whichever does not have a cable attached) as shown in Figure 1-1 on page 8.

When the adapter is used in High-Availability (HA) applications (such as MC/ServiceGuard) and it is required to be in the middle of the bus, the adapter’s terminator must be removed.

The SCSI bus must be properly terminated. Terminators may be ordered separately if needed (When ordered with the HBA, the part number is A4800A option 2. When ordered separately, the part number is C2905A). The first and last physical SCSI devices connected on the ends of the SCSI bus must have terminators attached. All other SCSI devices on the SCSI bus must have their terminators removed or disabled. Note that the host bus adapter is also on the bus.

The A4800A does not provide automatic termination.

When the adapter is used in HA applications that use two SCSI host bus adapters (such as MC/ServiceGuard) and it is required to be in the middle of the bus, the adapter’s SCSI ID will need to be changed (for example, from 7 to 6). Each device on the bus must have a unique ID. Refer to “The SCSI Command” on page 37.

To disable the adapter’s termination, you need to physically remove the terminator from the HBA connector. Termination for this bus must now be provided by some other SCSI device (e.g. disk, disk array, or other HBA, as required).

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