READ ELEMENT STATUS (B8h)The READ ELEMENT STATUS command is sent to a target from the initiator requesting that the targetreport the status of its internal elements.Bit 7 6 5 4 3 2 1 0Byte0 Operation Code (B8h)1 LUN VolTag Element Type Code2 (MSB) Starting Element Address3 (LSB)4 (MSB) Number of Elements5 (LSB)6 Reserved CurData DVCID7 (MSB)8 Allocation Length9 (LSB)10 Reserved11 ControlField descriptions:VolTag:If the VolTag bit is set the media changer shall return volume tag information in the elementdescriptors. If the VolTag bit is not set the media changer shall not return volume tag information.Element Type Code:This field specifies the element type or types selected to report in response to this command. Avalue of 0 indicates that status for all element types is to be reported.0h Report all element types1h Report Medium Transport Elements (Cartridge pickers)2h Report Storage Elements (Cartridge Slots)3h Report Import / Export Elements (I/O Slots)4h Report Data Transfer Elements (Tape drives)5h - Fh ReservedStarting Element Address:This field indicates the starting element address. Elements greater or equal than the startingaddress are returned.Number of Elements:This field specifies the maximum number of element descriptors to return. If the allocation length isnot sufficient to transfer all of the element information, the target transfers all the information thatcan be completely transferred; this is not an error condition.CurData:If the CurData bit is set the library shall return element status data without causing device motion.If the CurData bit is zero, the library may cause device motion to confirm element status data.Chapter 3. Supported SCSI Commands 3-53
