Description

Function description

This function block can be used to change the value range of a numerical variable.

and can be configured as additional parameters.

Formula

The function block carries out the following calculation:

Representation in FBD

Representation:

Representation in LD

Representation:

Representation in IL

Representation:

CAL SCALING_Instance (IN:=DigitalVariable, 
    PARA:=Parameters, OUT=>ScalingOutput, 
    STATUS=>StatusWord)

Representation in ST

Representation:

SCALING_Instance (IN:=DigitalVariable, PARA:=Parameters, 
    OUT=>ScalingOutput, STATUS=>StatusWord) ;

Parameter description SCALING

Input parameter description:

Parameter	Data type	Meaning
IN	REAL	Numerical variable to be scaled
PARA	Para_SCALING	Parameter

Output parameter description:

Parameter	Data type	Meaning
OUT	REAL	Scaled output value
STATUS	WORD	Status word

Parameter description Para_SCALING

Data structure description

Element	Data type	Meaning
in_min	REAL	Lower limit of the input scale
in_max	REAL	Upper limit of the input scale
out_min	REAL	Lower limit of the output scale
out_max	REAL	Upper limit of the output scale
clip	BOOL	"1": the value of the OUT output is limited by out_min and out_max.

EN stands for ENable; it is an optional block input. When the EN input is enabled, an ENO output is set automatically.

If EN = 0, the block is not enabled; its internal program is not executed, and ENO is set to 0.

If EN = 1, the block's internal program is run and ENO is set to 1. If an error occurs, ENO is set to 0.

If the EN input is not connected, it is set automatically to 1.

ENO

ENO stands for Error NOtification; this is the output associated with the optional input EN.

If ENO is set to 0 (because EN = 0 or in case of an execution error):

the status of the function block outputs remains the same as it was during the previous scanning cycle that executed correctly;
the output(s) of the function, as well as the procedures, are set to "0".

WORD

The type WORD is encoded in a 16 bit format and is used to perform processing on series of bits.

This table shows the upper/lower limits of each of the bases that can be used:

Base	Lower limit	Upper limit
Hexadecimal	16#0	16#FFFF
Octal	8#0	8#177777
Binary	2#0	2#1111111111111111

Examples of representation

Data	Representation in one of the bases
0000000011010011	16#D3
1010101010101010	8#125252
0000000011010011	2#11010011

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.