Accessing historical values - D2_CalcStatFunc function

The function allows you to calculate the specified statistical archive function on demand.

Declaration
D2_CalcStatFunc
(archIdent, bt, et, statFuncID, validPerc, paramIdent, refresh)

Parameters
archIdent TEXT
type
  • Reference to one value of historical value.
  • Reference to simple value of object (not structured variable).
  • In case of structured variable it is one item (SV.Struct[2]^Item),
    otherwise name of object (e.g. I/O tag).
    In this case the system will automatically look for a "suitable" objet of Historical value type.
    If the column "Item" is of the Object type it is possible to specify a string ",ALL" right after the name of column (e.g. SV.Struct[4]^Item,ALL). This causes the historical values to be obtained for the connected object, not for the item of a structured variable.
bt ABS. TIME type Interval begin time.
et ABS. TIME type Interval end time.
statFuncID INT type Statistical function type. The type is represented by a numerical value (see the table).
validPerc INT type Validation criteria.
paramIdent REAL or INT types Parameter for some types of functions.
refresh   Optional parameter of optional type.

Description

The function calculates the statistical function specified by the parameter statFuncID on the values represented by the historical value archIdent within the time interval given by the parameters bt and et. After successful execution, the function returns a result value.

The parameter validPerctIdent_Int represents Validation criteria used during evaluation of the statistical function. It can get the values within 0 .. 100 (the error ERR_RANGE_ERROR occurs if the condition is broken).

For some statistical function, it is required to enter the parameter paramIdent according to the table:

Statistical function Parameter description
_STAT_F_INTEGRAL Integral time units. For individual types, there are also established predefined local variables according to the table:
Constant Description
_INTEGRAL_HOURUNIT Hour integral
_INTEGRAL_MINUNIT Minute integral
_INTEGRAL_SECUNIT Second integral
_STAT_F_GE_TIME
_STAT_F_GT_TIME
_STAT_F_LE_TIME
_STAT_F_LT_TIME
_STAT_F_ADDITION_PARAM
_STAT_F_INCREMENT_PARAM
_STAT_F_DELTA_PARAM
 Reference value

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