Editing Analog Values

Introduction

This block library contains EFBs for the operation of analog modules. The EFBs are designed in such a way that it enables the FBD program configuration to be largely independent of the hardware module used. Hardware-dependent EFBs (e.g. family: Quantum IO Configuration) are used to evaluate project-specific information on the PLC and to process it in the hardware independent data structures and . Hardware independent EFBs work with these data structures (e.g. family: Analog I/O Scaling), that read, scale and convert raw values from the input words (%IWx) into values. This means that changes in direct addresses or changes in input/output parameters can be detected automatically by the EFBs.

Division into sections

As the detection of configuration data only occurs once after loading, it is advisable to divide the EFBs in the ANA_I/O library into at least two sections.

Division into at least two sections is recommended.

Scaling section
Configuration section

This division into a configuration section and several scaling sections can lead to a reduction of the CPU load, as the configuration part (configuration section) must only execute once, (after a cold restart or a warm restart). The scaling sections are usually executed continuously.

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)

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.