Page 78  Foundation Fieldbus RMA803 Remote Indicator User's Guide  Revision 4 
5.9  Arithmetic block 
The Arithmetic block is designed for using popular measurement math functions easily. The math 
algorithm is selected by name and the type of function to be performed. The block is used for 
calculating measurements from a combination of signals from the sensors. The block must not be 
used in a control path. The block does not support process alarms. 
The Arithmetic block supports the following functions: 
•  Flow compensation, linear 
•  Flow compensation, square root 
•  Flow compensation, approximate 
•  BTU flow 
•  Traditional Multiply Divide 
•  Average 
•  Traditional Summer 
•  Fourth order polynomial 
•  Simple HTG compensated level 
•  Fourth order Polynomial Based on PV 
 
 
Figure 16: Arithmetic block 
 
Execution 
The block has five inputs, namely IN, IN_LO, IN_1, IN_2, and IN_3. The first two inputs (IN, 
IN_LO) are designed for a range extension function that results in a Process Variable (PV), with the 
status indicating the input in use.