I_SCALE: Scaled analog input

Function description

The function converts data from the 16 bit integer format into the floating-point format. The scaling inputs MN and MX predefine the value range for the output. MN corresponds to 0 percent and MX to 100 percent. The integer input value is displayed in the floating-point range. If there are warning ranges for the current data format (e.g. 16 bit, +/- 10 V), the floating point value can be expanded to over 100 percent (e.g. 101.6 percent)

and can be configured as additional parameters.

NOTE: The I_SCALE function can not be used to scale temperature measurements. Please use the I_PHYS function to scale temperature measurements.

Representation in FBD

Representation:

Representation in LD

Representation:

Representation in IL

Representation:

LD InputChannel
I_SCALE ScalingInput0Percent,ScalingInput100Percent
ST ScaledValue

Representation in ST

Representation:

ScaledValue := I_SCALE (InputChannel,
    ScalingInput0Percent, ScalingInput100Percent) ;

Parameter description

Description of input parameters:

Parameter	Data type	Meaning
CHANNEL	ANL_IN	Input channel
MN	REAL	Scaling input, 0 percent
MX	REAL	Scaling input, 100 percent

Description of output parameters:

Parameter	Data type	Meaning
OUT	REAL	Scaled value

Runtime error

An error message is returned

if the input channel is not configured. In this case, please check the connected I/O module EFB.
in the case of input value underflow (for example, -1 Volt instead of 0 ... 5 Volt).
in the case of input value overflow (for example, 6 Volt instead of 0 ... 5 Volt).

NOTE: For a list of all block error codes and values, seeAnalog I/O Scaling .

NOTE: To evaluate the status information for the I/O module, use the I_SCALE_WARN function block.

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".

ANL_IN

ANL_IN is an internal data type that is used between Quantum specific FFBs. For instance, an ACI040 FFB provides the channels structures of the module as ANL_IN types, which are used as input of an I_FILTER FFB. This data type must not be used outside the Quantum specific FFBs.

Elements of the DDT:

Name	Type	Comment
valuePtr	UDINT	3x or 4x raw value register
rawControl	BYTE	Control Byte(internal use only)
rawSpecific	BYTE	Specific Byte (internal use only)
offset	INT	Offset Value
range	WORD	Input range (resolution)
channel	BYTE	Input Channel number
statusMode	BYTE	Status Mode (internal use only)
statusPtr	UDINT	Identifies high byte or low byte of status register
warnCode	BYTE	Warning Code (internal use only)

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.