3-1SectionData Carrier Motion and Command Conditions
18
path
to the host computer is cleared and the host computer can then send com
-
mands to the ID Controller’s other R/W Head.
(Host
Computer)
Polling auto
command
Sub-
command
Response
DC
Response
Head 1
(ID Controller)
(DC)
Not close
Not close
(Head 1)
(Head 2)
(Head 1)
Polling auto
command
(Inquiry to head 1)
Sub-
command
(Inquiry to head 1)
Response
(Head 2)
(Not close
to head 1)
Head 1
processing
completed
Read/W
rite
Processing
Response
Passes on
Not close
Sub-
command
(Inquiry to head 2)
Response
Not close
(Not close
to head 2)
1, 2, 3...
1. A polling auto command is sent to Head 1.
2. The
ID Controller receives the command and returns a response
indicating
that it has received the command.
3. A polling auto command is sent to Head 2.
4. The
ID Controller receives the command and returns a response
indicating
that it has received the command.
5. The
host computer can query the status of processing using subcommands
or suspend polling auto processing.
6. When
the DC is not close to the specified R/W Head, a “not close” response
is returned in response to a query subcommand.
7. When
the DC passes in front of a R/W Head, write or read processing is
per
-
formed.