AlarmStorageReader (FB)

FUNCTION_BLOCK AlarmStorageReader EXTENDS AlarmStorageManager

This function block is used to read data from the alarm storage. We use a function block instead of functions to be able to store some state like the already opened table or alarm storage.

InOut:

Scope Name Type Initial Comment Input _hLock RTS_IEC_HANDLE RTS_INVALID_HANDLE Used to synchronize the access to THIS instance, because there might be a potential usage from the application code, not only from the visualization code

Methods:

AddAlarmStorageListener

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FB_Init

GetFirstLastRowID

GetMinMaxTimestamps

Read

RemoveAlarmStorageListener

SemaphoreAcquire

SemaphoreRelease

prvReadLatchVarString

prvReadLatchVarString2

prvRetrieveLatchVarValue

prvTblAlarmFindTimestamp

Structure: