Page 80 Foundation Fieldbus RMA803 Remote Indicator User's Guide Revision 4
2. Flow compensation, square root. Usually, IN_1 is pressure, IN_2 temperature, and IN_3 is the
compressibility factor Z.
= ×
=
(_1)
(_2)
(_3)
× []
3. Flow compensation, approximate. Both IN_2 and IN_3 would be connected to the same
temperature.
= ×
=
(_1)×(_2)×(_3)×(_3) × []
4. BTU flow, where IN_1 is inlet temperature, and IN_2 the outlet temperature.
= ×
= (_1 _2) × []
5. Traditional Multiply Divide
= ×
=
(_1)
(_2)
+ (_3)× []
6. Average
=
(+
(
_1
)
+
(
_2
)
+ (_3))
f = number of inputs used in computation (unusable inputs are not used).
7. Traditional Summer
= +
(
_1
)
+
(
_2
)
+ (_3)
8. Fourth order polynomial. All inputs except IN_LO (not used) are linked together.
= PV + (_1)
+ (_2)
+ (_3)
9. Simple HTG compensated level, where PV is the tank base pressure, IN_1 is the top pressure,
IN_2 is the density correction pressure, and GAIN is the height of the density tap.
=
((_1))
((_2))
10. Fourth order polynomial based on PV
= PV + GAIN_IN_1×()
+ GAIN_IN_2×()
+ GAIN_IN_3×()
After the value of func is calculated, it is multiplied by GAIN, and then BIAS is added to the result.
Then, the high and low output limits are applied as per configured range scaling, and PRE_OUT is
updated with the calculated value. If the mode is AUTO, PRE_OUT is copied to OUT.
To Next Page
Loading...
Need help?
General
