Figure 21: Arithmetic Schematic Diagram - Honeywell SLG 700 Option Manual

3.12.1.
The range extension function has a graduated transfer controlled by two constants referenced to IN. An
internal value, g, is zero for IN less than RANGE_LO. It is one when IN is greater than RANGE_HI.
It is interpolated from zero to one over the range of RANGE_LO to RANGE_HI. The equation for
PV follows:
If the status of IN_LO is not usable and IN is usable and greater than RANGE_LO, then g is set to
one. If the status of IN is unusable, and IN_LO is usable and less than RANGE_HI, then g is set to
zero.
For three auxiliary inputs, six constants are used, and each input has a BIAS_IN_i and a GAIN_IN_i.
The output has a BIAS and a GAIN static constant. For the inputs, the bias is added, and the gain is
applied to the sum. The result is an internal value called t_i in the function equations. The equation for
each auxiliary input is the following:
If an auxiliary input is unstable, to assure smooth degradation, the flow compensation functions have
limits on the amount of compensation applied to the PV. The internal limited value is f.
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Figure 21: Arithmetic Schematic Diagram

Calculation of PV
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FOUNDATION Fieldbus Option User's Manual Rev.5