UMAX030211 Version 1.0.2. Preliminary Documentation – May be subject to change
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0 =
True when InA Equals InB
1 !=
True when InA Not Equal InB
2 >
True when InA Greater Than InB
3 >=
True when InA Greater Than or Equal InB
4 <
True when InA Less Than InB
5
<
=
True when InA Less Than or Equal InB
6 OR
True when InA or InB is True
7 AND
True when InA and InB are True
8 XOR
True when InA/InB is True, but not both
9 +
Result = InA plus InB
10 -
Result = InA minus InB
11 x
Result = InA times InB
12 /
Result = InA divided by InB
13 MIN
Result = Smallest of InA and InB
14 MAX
Result = Largest of InA and InB
Table 22 – Object 4y50h Math Function Operators
For Function 1, InA and InB are Math Inputs 1 and 2, respectively.
For Function 2, InA is the result of Function 2 and InB is Math Input 3, respectively.
For Function 3, InA is the result of Function 3 and InB is Math Input 4, respectively.
For a valid result in each Function, both inputs must be non-zero value (other than
‘Control Source
Not Used’
). Otherwise, the corresponding Function is ignored, and the “Output Data” for the math
function block is the result of the earlier function scaled according to the output objects. For example,
if Math Input 4 is not used, the math output would be the result of the Function 3 operation.
For logical operators (6 to 8), any SCALED input greater than or equal to 0.5 is treated as a TRUE
input. For logic output operators (0 to 8), the result of the calculation for the function will always be
0 (FALSE) or 1 (TRUE).
Error data (i.e. input measured out of range) is always treated as a 0.0 input into the function.
For the arithmetic functions (9 to 14), it is recommended to scale the data such that the resulting
operation will not exceed full scale (0 to 100%) and saturate the output result.
When dividing, a zero InB value will always result is a zero output value for the associated function.
When subtracting, a negative result will always be treated as a zero, unless the function is multiplied
by a negative one, or the inputs are scaled with a negative coefficient first.
The resulting final mathematical output calculation is in the appropriate physical units using object
4021h
Math Output Scaling 1 PV
and 4023h
Math Output Scaling 2 PV
. These objects are also
considered the Min and Max values of the Math Block output and apply the resolution shift defined
by object 4032h
Math Output Decimal Digits PV
. The result is written to read-only object 4030h
Math Output PV
. These scaling objects should also be taken into account when the Math Function
is selected as the input source for another function block, as outlined in Table 24.
