O_SCALE_WARN: Scaled analog output with warnings status

Function description

The function block converts values from the floating point format into 16 bit integer format. The scaling inputs MN and MX predefine the value range for the analog output. MN corresponds to 0 percent and MX to 100 percent of the output range (e.g. -10 ...10 V).

In addition the function block at the WARN_NEG and WARN_POS outputs indicate whether a status warning has occurred in the connected analog output EFB.

and can be configured as additional parameters.

Representation in FBD

Representation:

Representation in LD

Representation:

Representation in IL

Representation:

CAL O_SCALE_WARN_Instance (CHANNEL:=OutputChannel,
    MN:=ScalingInput0Percent, X:=FloatingPointValue,
    MX:=ScalingInput100Percent,  WARN_NEG=>UnderflowFlag,
    WARN_POS=>OverflowFlag)

Representation in ST

Representation:

O_SCALE_WARN_Instance (CHANNEL:=OutputChannel,
    MN:=ScalingInput0Percent, X:=FloatingPointValue,
    MX:=ScalingInput100Percent,  WARN_NEG=>UnderflowFlag,
    WARN_POS=>OverflowFlag) ;

Parameter description

Description of input parameters:

Parameter	Data type	Meaning
CHANNEL	ANL_OUT	Output channel
MN	REAL	Scaling input, 0 percent
X	REAL	Floating-point value
MX	REAL	Scaling input, 100 percent

Description of output parameters:

Parameter	Data type	Meaning
WARN_NEG	BOOL	0: no output value underflow at the closed analog output EFB 1: output value underflow at the closed analog output EFB X < MN
WARN_POS	BOOL	0: no output value overflow at the closed analog output EFB 1: output value overflow at the closed analog output EFB X > MX

Runtime error

An error message is returned

if the output channel is not configured. In this case, please check the connected I/O module EFB.
if the values of MN and MX are identical causing an internal module division by zero.
with an output value underflow (outside the warning range, e.g. –1 Volt instead of 0 ... 5 Volt).
with an output value overflow (outside the warning range, e.g. 6 Volt instead of 0 ... 5 Volt).
if the connected analog output EFB is unable to generate status information and the warning outputs can, therefore, never become active. In this case, please use the O_SCALE procedure.

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

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_OUT

ANL_OUT is an internal data type that is used between Quantum specific FFBs. For instance, an ACO130 FFB provides the channel structures of the module as ANL_OUT types, which are used as input of an O_PHYS 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.