HP Surestore 28/48-Slot with DLT7000 Digital Linear Tape SCSI-2 Drive and SCSI - Page 29

SCSI Command Overview Library Control Commands Information Transfer Phase The command, data, status, and message phases are all grouped together as the information transfer phases because they are all used to transfer data or control information via the data bus. The library only supports asynchronous transfers with a maximum size of 32Kbytes. During all transfer phases that the device writes data to the SCSI bus, odd parity is generated. Parity is checked during all transfer phases where data is read from the bus, but can be disabled. Data Phase The data phase encompasses both the Data In phase and the Data Out phase. • The Data In phase allows the target to request that its data be sent to the initiator. • The Data Out phase allows the target to request that data from the initiator be sent to the target. Command Phase The command phase allows the target to request command information from the initiator. Chapter 1 1- 5