HP LTO 4 FC, LTO 4 SCSI, LTO 4 SAS manual Automation/Device Interface ADI

Automation/Device Interface (ADI)

There are two elements to the Automation/Device Interface (ADI):

•ADI Transport Protocol (ADT)—a standard protocol for communication between a SCSI automation device and a SCSI data transfer device, such as a tape drive.

The ADT protocol allows conforming ADI SCSI devices to inter-operate. The objectives of ADT are:

•To provide a low-cost interconnect method between an automation device and the data transfer devices that reside within the media changer.

•To standardize this interface so that different disk drives, tape drives, optical media drives, and other SCSI devices may be added to conforming media changers without requiring modifications to generic system hardware.

•To provide for the addition of special features and functions through the use of vendor-specific options.

The interface protocol includes provision for the connection of two SCSI ports. One of these ports is intended to be attached to a media changer device and may operate either as a SCSI initiator port or a SCSI initiator/target port. The other port is intended to be attached to a data transport type device (tape drive) and may operate as either a SCSI target port or SCSI initiator/target port. No provision is made for connection of more than two ports.

•ADI Commands (ADC-2)—an extension to the SCSI command set for communication with application clients through the ADI.

The objectives of ADC-2 are:

•To permit an application client to communicate over a SCSI service delivery subsystem, with a logical unit that declares itself to be an ADI device in the Peripheral Device Type field of the standard INQUIRY data.

•To define commands unique to the ADI device type.

•To define commands and parameters to manage the operation of the ADI device type and the operation of logical units of other specific device types that are present in the same device as the ADI logical unit.

For details of HP’s implementation of these standards, see the HP ADI Firmware Integration Guide. The T10 standards referenced by this guide are as follows:

•ADT: ANSI INCITS 406-2005

•ADC-2: T10/1741-D revision 7d.

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