Hitachi EH-150 Series Applications Manual page 180

Appendix
Task code H17
 Function
Forces the cancel of CPU occupation. This command is used in situations such as when another programming
device has gone down due to an error while occupying the user memory of the CPU (function selection H00).
When connecting the host to the CPU and occupying it for the first time, use function selection H01 so the local
occupation status is canceled forcibly.
This task code can also be executed when the CPU is not occupied.
 Execution condition
 Request format
H 1 7 (a)
 Response format
(a) H 1 7
With forced cancel, if there are modification in the parameter area, the same processing as parameter
modification completion processing is performed (refer to the task code H27) as well as the canceling of
memory occupation.
1] Forced cancel of all occupation (subcommand H00)
All occupation is canceled unconditionally, so when this command has been executed the peripheral that is
reading the user memory, for example, will not be able to perform reading. Therefore, verify the registered
peripherals by monitoring the occupation table (WRF040 to WRF04B) when executing this command.
Member registration area
A
B
READ occupied by the
peripherals A, B
2] Forced cancel of local station occupation (subcommand H01)
Cancels the occupation of the local station.
The occupation of other stations are maintained.
Member registration area
A
B
C
READ occupied by the
peripherals A, B
Forced cancel of occupation
CPU Status
Occupation
READ occupation
WRITE occupation
Not occupied
(a) Function selection (subcommand)
1] H00: Forced cancel of all occupation
2] H01: Forced cancel of local station occupation
(a) Response task code (H00 when executed normally)
For task codes other than the normal task codes, refer to the "response list by
task code" at the end of this chapter.
All peripheral registrations
are canceled
The occupancy by the local
seation (B) is forcibly canceled.
STOP RUN HALT
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READ
request
Non executable error
Even if peripheral A or B issues a
READ request, a not-executable
error is sent because the occupancy
is already being forcibly canceled.
A
C
A - 16
Classification
CPU Control
ERROR
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