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Using Tasks Section 4-2
WORK SEND: SEND(090), NETWORK RECEIVE: RECV(098), DELIVER
COMMAND: CMND(490), PROTOCOL MACRO: PMCR(260).
4-2-3 Flags Related to Tasks
Flags Related to Cyclic Tasks
The following flag work only for normal cyclic tasks. They do not work for extra
cyclic tasks.
Task Flags
(TK00 to TK31)
A Task Flag is turned ON when a cyclic task in READY status and is turned
OFF when the task is in Disabled (INI) or in Standby (WAIT) status. Task num-
bers 00 to 31 correspond to Task Flags TK00 to TK31.
Note Task Flags are used only with cyclic tasks and not with interrupt tasks. With
an interrupt task, A44115 will turn ON if an interrupt task executes after the
start of operation, and the number of the interrupt task that required for maxi-
mum processing time will be stored in two-digit hexadecimal in A44100 to
A44107.
Initial Task Execution Flag
(A20015)
The Initial Task Execution Flag will turn ON when cyclic tasks shift from Dis-
abled (INI) to READY status, the tasks obtain the right to execute, and the
tasks are executed the first time. It will turn OFF when the first execution of the
tasks has been completed.
The Initial Task Execution Flag tells whether or not the cyclic tasks are being
executed for the first time. This flag can thus be used to perform initialization
processing within the tasks.
Note Even though a Standby cyclic task is shifted back to READY status through
the TKON(820) instruction, this is not considered an initial execution and the
Initial Task Execution Flag (20015) will not turn ON. The Initial Task Execution
Flag (20015) will also not turn ON if a cyclic task is shifted from Disabled to
RUN status or if it is put in Standby status by another task through the
TKOF(821) instruction before the right to execute actually is obtained.
Task 3
Cycle Cycle Cycle
Disabled READY StandbyREADY
Task Fla
for task 3
Task n
Ready
Disabled
Initial Task
Execution Flag
Ready
Disabled
Initializing
processing
Initial Task Execution Flag
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