SEMIDSTATE
(Statement)
[RC7 Version 2.2 or later]
Returns the current status (enabled or disabled) of the specified semaphore ID.
SEMIDSTATE (<SemaphoreID>)
This function returns the enabled (1) or disabled (0) status of the specified semaphore ID. Executing CREATESEM enables a semaphore ID and executing DELETESEM disables it.
Create a semaphore to be used in PRO1 and PRO2, as a supervisory task TSR1, only when the SEMIDSTATE returns the disabled status of the specified semaphore ID.
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'!TITLE "Create semaphore"
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PROGRAM TSR1
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FOLDER DEFINT SEMID
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'Only when SEMID is not 1 (enabled), create a semaphore.
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IF SEMIDSTATE (SEMID) <> 1
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SEMID = CREATESEM (0)
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ENDIF
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END
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'!TITLE "Semaphore control in writing to I0"
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PROGRAM PRO1
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EXTERN DEFINT SEMID
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TAKESEM SEMID
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I0=1
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GIVESEM SEMID
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END
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'!TITLE "Semaphore control in writing to I0"
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PROGRAM PRO2
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EXTERN DEFINT SEMID
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TAKESEM SEMID
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I0=1
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GIVESEM SEMID
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END
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