5190/5194 Modular Tape Subsystem Manual

Operating the Cartridge Tape Drive and ACL
5190/5194 Modular Tape Subsystem Manual—426878-002
4-18
Selecting the Operating Mode
Selecting the Operating Mode
The operating mode controls how cartridges are loaded into the tape drive from the
ACL cartridge magazine. The ACL can be set to operate in three modes: manual,
auto, and system.
Status indicator LEDs on the ACL control panel indicate the current operating mode.
Before using the ACL, always make sure the tape drive is in the auto mode. If the
mode is not auto, press the MODE SEL button to change the operating mode to auto.
Under normal operating conditions, it shouldn’t be necessary to use the MODE SEL
button.
In the auto mode, cartridges are selected and loaded sequentially. When the ACL
receives a load command from the system, the ACL loads either the topmost cartridge
in the magazine or the cartridge specified on the cartridge position indicator. When the
ACL receives an unload command, the ACL unloads the current cartridge and
automatically loads the next cartridge.
Rewinding and Unloading Cartridges
Unloading a cartridge tape means ejecting it from the tape drive. The drive must be
powered on to unload a cartridge. In the auto mode, the ACL unloads cartridges
automatically when it receives an unload command from the system. If you interrupt
the system and unload a cartridge using the ACL control panel, the message panel
informs you that the auto mode was interrupted.
Use the following procedure to unload a cartridge from the drive and return it to the
ACL cartridge magazine using the ACL control panel buttons:
1. Press the RESET button. The message panel shows NT RDYU or NT RDYF.
These are the NOT READY drive states. See NOT READY States
on page 4-30
for more information.
2. Press the UNLOAD button to eject the cartridge from the drive. If the tape needs
rewinding, the drive automatically begins rewinding the tape and the REWINDNG
message appears on the message panel. If the tape position is at EOT, the 5190
tape drive takes approximately 60 seconds to rewind the tape and unload the
cartridge. The 5194 tape drive could take 1 second or less, because EOT and
BOT are located at the same position. During unloading, the UNLOADNG
message appears on the message panel. When the tape is unloaded, the AUTO
MODE WAS INTERRUPTED message appears.
3. Press RESET to clear the message.
Caution. NonStop Himalaya systems support only the auto mode. Do not change the
operating mode. If the ACL is not in auto mode, system utilities such as BACKUP might
operate unpredictably.