Echelon FTXL - Manual (Page 48)

36 Creating a Model File
There is one gain setting per channel, implemented as an array of configuration
network variables (CPNVs), of type SCPTgain, where the elements of the array
are distributed among the four functional blocks contained in the functional block
array. Because the SCPTgain configuration property has a default gain factor of
1.0, no explicit initialization is required for this configuration property network
variable.
There is a single offset setting, implemented as a configuration network variable
(CPNV), of type SCPToffset. This CPNV applies to all channels, and is shared
among the elements of the functional block array. The SCPToffset configuration
property has a default value of zero.
The SCPToffset configuration property is a type-inheriting configuration
property. The true data type of a type-inheriting property is the type of the
network variable to which the property applies. For an SFPTopenLoopSensor
standard functional profile, the SCPToffset configuration property applies to the
functional block, and thus implicitly applies to the profile's primary member
network variable. In this example, the effective data type of this property is
SNVT_volt (inherited from nvoAnalogValue).
The example also includes a five-point linearization factor, implemented as a
configuration property array of type SCPTsetpoint. The SCPTsetpoint
configuration property is also a type-inheriting configuration property, and its
effective data type is also SNVT_volt in this example.
Because the SCPTsetpoint linearization factor is a configuration property array,
it applies to the entire array of functional blocks, unlike the array of SCPTgain
configuration property network variables, whose elements are distributed among
the elements of the functional block array. In this example, the linearization
configuration property array is implemented with configuration property network
variables, and must be shared among the elements of the functional block array.
To implement the linearization array of configuration properties such that each
of the four functional blocks has its own linearization data array, you must
implement this configuration property array in files, and declare the
configuration property with the cp_family modifier.
Table 6 shows the relationships between the members of the functional-block
array. As the table shows, each channel has a unique gain value, but all
channels share the offset value and linearization factor.
Table 6. Functional-Block Members for the Four-Channel ADC
Channel Gain Offset Linearization
fbAdc[0] nciGain[0]
fbAdc[1] nciGain[1]
fbAdc[2] nciGain[2]
fbAdc[3] nciGain[3]
nciOffset nciLinearization[0..4]