HP LTO Ultrium 4 drives technical reference manual, volume 2: software integration 43
HP restricted
Table 1 Non-queued ACI commands
Table 2 Queued ACI commands
Treatment of reserved fields
To ensure forwards compatibility with future versions of the ACI, automation controller firmware
should set any command fields labelled as ‘Reserved’ to zero. Likewise, automation controller
firmware should mask off any response fields labelled as ‘Reserved’ during the processing of tape
drive responses. This will allow older versions of automation controller firmware to operate
successfully with newer versions of tape drive firmware.
Recommended power-up sequence
After power-up, HP recommends that the automation controller wait until it has received at least one
ASCII <ENQ> character from the tape drive before attempting a command-response transaction. HP
Ultrium tape drives use a two-step power-up sequence and the drive sends <ENQ> to signal the
transition between the steps. The drive sends the first <ENQ> within 500 milliseconds of exiting the
reset state after receiving power. Note that the default baud rate at power-up is 9600.
Consider sending Get Drive Info as the first command, either packetized or primitive. This retrieves a
variety of useful identifying information identifying the tape drive, including the version of the ACI
protocol that the tape drive supports.
ACI Command Recommended time-out value
Get Drive Info 5s
Get Drive Status 5s
Get Drive Configuration 5s
Get Error Info 5s
Get Buffer Size 5s
No Op 5s
Acknowledge Attention 5s
ACI Command Recommended time-out value
ACI Load—immediate 5s
ACI Load—non-immediate (drive idle, unloaded) 300s
ACI Unload—immediate 5s
ACI Unload—non-immediate (tape loaded, at EOM,
drive idle)
300s or 9000s depending on
implementation strategy
Set Drive Configuration (tape loaded, at EOM, SCSI
unload)
300s or 9000s depending on
implementation strategy
ACI Reset—ACI bus 5s
ACI Reset—drive 5s
Set Baud Rate 5s
