Echelon LonPoint Application and Plug-In - Manual (Page 81)

The LonPoint Application and Plug-in Guide 8-9
The type of the values in the Output column depend
on the Analog Output network variable type you
selected on the Analog Function Block tab.
The type of the values in the Input column cannot
always be determined. For Add and Subtract
functions the units are normally displayed. All other
cases show units as ? (Native) and the values
shown are in (or derived from) the native units of the
input network variables (normally SI units). Caution
should be used when scaling Fahrenheit
temperatures. You can temporarily change the
format of the input network variables to SI units to
verify your values.
Scaling can be set up to be Reverse Acting (i.e. the
output decreases as the input increases) by setting
the High value lower than the Low value for either
the Input or the Output column (but not both).
Scaling is applicable to all analog output function
types except Enthalpy.
Override This field exists for both the A_Out and
Digital_Out
network variables. This value will be
sent on the corresponding output network variable
when the AFB functional block is put into override.