FP_AVERAGE_BUFFER_DEFINE

Define buffer area for moving average and total values

This FP instruction specifies a special buffer to compute the average value and the total of all contained values. The starting address is set by d_Start and the size by n_Words. The buffer has a particular structure, which is shown in the programming example, where the number of array elements of the last element iArrData corresponds to the size defined by n_words. Use the instruction FP_AVERAGE_BUFFER_WRITE for writing into the buffer.

Parameters

Input

n_Words (WORD, INT, UINT)

Specifies the memory size of the buffer

Values: 1–30000

Output

d_Start (WORD, INT, UINT)

Starting data area of the buffer

We recommend using a user-defined DUT as shown in the programming example.

Error flags

sys_bIsOperationErrorHold (turns to TRUE and remains TRUE)

if a value specified for a parameter is outside the permissible range.

sys_bIsOperationErrorNonHold (turns to TRUE for one scan)

if a value specified for a parameter is outside the permissible range.

Example

DUT

Elements of the DUT (identifiers):

uiBufferSize: Size of buffer
uiNumberOfStoredData: Number of stored data
diTotalValueOfStoredData: Total sum of stored data
rMovingAverage: Moving average
uiWritePointer: Position of writing pointer
iArrData: Contains the values of the buffer. The number of integer values (10 in this example) must be equal to the size of the buffer defined with iNumberOfIntegerValues.

POU header

All input and output variables used for programming this function have been declared in the POU header. The same POU header is used for all programming languages.

	VAR
		bDefine: BOOL:=FALSE;
		bWrite: BOOL:=FALSE;
		iCounter: INT:=0;
	END_VAR
	VAR CONSTANT
		iNumberOfIntegerValues: INT:=10;
			(*number of integers values must be equal to average buffer size*)
	END_VAR
	VAR
		dutAverageBufferInt10: DUT_FP_AVERAGE_BUFFER_INT_10;
			(*Average Buffer for integer numbers of size 10*)
	END_VAR

POU body

When the variable bDefine is set to TRUE, the function is carried out.

LD body

BODY
    WORKSPACE
        NETWORK_LIST_TYPE := NWTYPELD ;
        ACTIVE_NETWORK := 0 ;
    END_WORKSPACE
    NET_WORK
        NETWORK_TYPE := NWTYPELD ;
        NETWORK_LABEL :=  ;
        NETWORK_TITLE :=  ;
        NETWORK_HEIGHT := 6 ;
        NETWORK_BODY
B(B_F,FP_AVERAGE_BUFFER_DEFINE!,,13,2,28,6,,?DEN?Dn_Words?AENO?Cd_Start);
B(B_VARIN,,iNumberOfIntegerValues,11,4,13,6,);
B(B_VAROUT,,dutAverageBufferInt10,36,4,38,6,);
B(B_CONTACT,,bDefine,4,1,6,3,);
B(B_F,Adr_Of_Var_O!,,28,4,36,6,,?D?C);
L(1,2,4,2);
L(6,2,6,4);
L(6,4,13,4);
L(1,0,1,6);
        END_NETWORK_BODY
    END_NET_WORK
    NET_WORK
        NETWORK_TYPE := NWTYPELD ;
        NETWORK_LABEL :=  ;
        NETWORK_TITLE :=  ;
        NETWORK_HEIGHT := 8 ;
        NETWORK_BODY
B(B_CONTACT,,bWrite,2,1,4,3,);
B(B_CONTACT,,bDefine,6,1,8,3,N);
B(B_F,FP_AVERAGE_BUFFER_WRITE!,,14,2,28,6,,?DEN?D@'s'?AENO?Cd_Start);
B(B_VARIN,,sys_iRingCounter_2ms5,12,4,14,6,);
B(B_F,Adr_Of_Var_O!,,28,4,36,6,,?D?C);
B(B_VAROUT,,dutAverageBufferInt10,36,4,38,6,);
B(B_CONTACT,,sys_bPulse1s,11,1,13,3,R);
L(1,2,2,2);
L(4,2,6,2);
L(8,2,11,2);
L(13,2,13,4);
L(13,4,14,4);
L(1,0,1,8);
        END_NETWORK_BODY
    END_NET_WORK
END_BODY

ST body

IF (bDefine) then
    FP_AVERAGE_BUFFER_DEFINE(n_Words := iNumberOfIntegerValues,
                             d_Start => Adr_Of_Var(dutAverageBufferInt10));
END_IF;

If (bWrite) AND NOT (bDefine) AND DF(sys_bPulse1s) then
    FP_AVERAGE_BUFFER_WRITE(s := sys_iRingCounter_2ms5,
                            d_Start => Adr_Of_Var(dutAverageBufferInt10));
End_if;