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PointOldValue

PointOldValue

Declaration

void (_stdcall *PointOldValue)(HOBJ PtID, KomUniVal *Val, unsigned int Stat, int TransId);

Parameters

PtID

I/O tag ID.

Val

Pointer to KomUniVal structure with the historical value of the I/O tag.
WARNING: Do not use and write directly into KomUniVal structure of the I/O tag (the parameter ppPtVal) in the PointPar structure. This structure is used by the process D2000 KOM to compare with a new value and the value is sent to the system if the value or status of the new value and previous one are not the equal. This behaviour can be influenced in part by the attribute Stat (see next parameter).

Stat

Attributes for writing a new value. Possible values:

  • 0 - no attributes

  • ST_SOURCE_LIMITS - settings of limits is given by user - the states InLimit, VL_Limit, L_Limit, H_Limit, VH_Limit are set by user and not by the process D2000 KOM

TransID

ID of the transaction, which was sent by the process D2000 Server as a parameter of the procedure ReadStoredData.

Description

The function sends a historical value of an I/O tag, which is obtained by calling the function ReadStoredData, to the system. The value is not inserted into the system as current one but it is saved by the D2000 Archiv process.