EUConversion Struct Reference
[RTDB Access API]

#include <simrtdb.h>

Public Member Functions
double numerators[EU_MAXPOLYNOMIAL]	__attribute__ ((aligned(8)))
double denominators[EU_MAXPOLYNOMIAL]	__attribute__ ((aligned(8)))
double rangesX[EU_MAXTABLEENTRIES]	__attribute__ ((aligned(8)))
double rangesY[EU_MAXTABLEENTRIES]	__attribute__ ((aligned(8)))
double rangesInvertedX[EU_MAXTABLEENTRIES]	__attribute__ ((aligned(8)))
double rangesInvertedY[EU_MAXTABLEENTRIES]	__attribute__ ((aligned(8)))
double directA	__attribute__ ((aligned(8)))
double directB	__attribute__ ((aligned(8)))
double inverseA	__attribute__ ((aligned(8)))
double inverseB	__attribute__ ((aligned(8)))
Data Fields
int	hashIndex
char	name [MAX_EUCONVERSIONNAME]
int	type
int	flags
int	nRanges
char	description [MAX_DESCRIPTIONLEN]
char	engUnits [MAX_EUNITSLEN]

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Detailed Description

Engineering conversion record held in shared memory. This is indexed via a separate hash table pointed to in the EUFactors meta data. This defines a conversion from physical (Engineering units) to raw via either a rational polynomial function as raw = (a*X^2 + b*X + c)/(d*X^2 + e*X + F) or
an interpolation table defined in rangesX and rangesY.
When the polynomial is different from strictly linear , i.e. A*X + B, this function cannot be inverted and therefore cannot be used to convert from physical to raw units.

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Member Function Documentation

double numerators [EU_MAXPOLYNOMIAL] EUConversion::__attribute__

(

(aligned(8))

)

a,b,c coefficients.

double denominators [EU_MAXPOLYNOMIAL] EUConversion::__attribute__

(

(aligned(8))

)

d,e,f coefficients.

double rangesX [EU_MAXTABLEENTRIES] EUConversion::__attribute__

(

(aligned(8))

)

double rangesY [EU_MAXTABLEENTRIES] EUConversion::__attribute__

(

(aligned(8))

)

double rangesInvertedX [EU_MAXTABLEENTRIES] EUConversion::__attribute__

(

(aligned(8))

)

double rangesInvertedY [EU_MAXTABLEENTRIES] EUConversion::__attribute__

(

(aligned(8))

)

double directA EUConversion::__attribute__

(

(aligned(8))

)

For linear conversion only. Those are calculated a load time. Raw = directA * Physical_value + directB .

double directB EUConversion::__attribute__

(

(aligned(8))

)

double inverseA EUConversion::__attribute__

(

(aligned(8))

)

For linear conversion only. Pysical_value = inverseA * Raw + inverseB .

double inverseB EUConversion::__attribute__

(

(aligned(8))

)

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Field Documentation

int EUConversion::hashIndex

Index # in hash table for this item

char EUConversion::name[MAX_EUCONVERSIONNAME]

Name of this conversion.

int EUConversion::type

Type of conversion

See also:

EUConversionType. By default, conversion is physical to raw. raw to physical to raw defined by oring with EU_RAWTOPHYSICAL

int EUConversion::flags

Whether the polynomial is linear and can be inverted.

int EUConversion::nRanges

Number of entries in interpolation table.

char EUConversion::description[MAX_DESCRIPTIONLEN]

Conversion description

char EUConversion::engUnits[MAX_EUNITSLEN]

Engineering unit descriptor for physical units.

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The documentation for this struct was generated from the following file:

• simrtdb.h