Description

Function description

The function block creates a moving average value (with frozen correction factor) with up to 10,000 input values.

The function block has both a manual and automatic mode.

NOTE: This function block performs an internal initialization in the first program cycle after a warm start or cold start (e.g. application download or power cycle) of the PLC program.

Due to this, you have to make sure that the function block is invoked in the first program cycle. In case of invoking the function block in a later program cycle, the internal initialization will not be performed, the value Y(old) will not be sure and the output Y(new) may deliver a wrong value.

WARNING

UNEXPECTED OUTPUT BEHAVIOUR

Make sure that the function block is always invoked in the first program cycle.

Failure to follow these instructions can result in death, serious injury, or equipment damage.

and can be configured as additional parameters.

Formula

Block formula:

Explanation of the variables

Variable	Description
Y (new)	Y Value in current program cycle
Y (old)	Y Value from the last program cycle
K	Correction factor
X	X Value in current program cycle

Representation in FBD

Representation:

Representation in LD

Representation:

Representation in IL

Representation:

CAL AVGMV_K_Instance (MAN:=Mode, X:=InputValue, 
    K:=CorrectionFactor, YMAN:=ManualValue, Y=>Average)

Representation in ST

Representation:

AVGMV_K_Instance (MAN:=Mode, X:=InputValue, 
    K:=CorrectionFactor, YMAN:=ManualValue, Y=>Average) ;

Parameter description

Description of input parameters:

Parameter	Data type	Description
MAN	BOOL	"0" = Automatic operating mode; "1" = Manual operating mode
X	REAL	Input
K	INT	Correction factor (max. 10,000)
YMAN	REAL	Manual value

Description of output parameters:

Parameter	Data type	Description
Y	REAL	Average value

Runtime error

For a list of all block error codes and values, see Measurement.

REAL

The REAL type is encoded in a 32 bit format.

The possible value ranges are shown in the figure below:

When a result is:

between -1,175494e-38 and 1,175494e-38, it is considered to be a DEN;
less than -3.402824e+38, the symbol -INF (for - infinity) is displayed;
greater than +3.402824e+38, the symbol INF (for + infinity) is displayed;
undefined (square root of a negative number), the symbolNAN is displayed.

NOTE: The IEC 559 standard defines two classes of NAN: the silent NAN (QNAN) and the signaling NAN (SNAN). A QNAN is a NAN with a most significant fraction bit while an SNAN is a NAN without a most significant fraction bit (bit number 22). QNANs can be propagated via most arithmetic operations without throwing an exception. As for SNANs, they generally indicate n invalid operation when they are used as operands in arithmetic operations (see %SW17 and %S18).

NOTE: When a DEN (non-standardized number) is used as an operand, the result is not significant.