ABB CM30 User Manual page 57

ControlMaster CM30 and CM50
Universal process controllers,
...Functions / ...Math Blocks
Equation Setup
Source 1 (2)
Source 1 (2)
Constant
Operator 1 (3)
End
Add
Subtract
Multiply
Divide
Low Select
High Select
Median
Real Time Average Setup
Source 1
Reset Source
Average Duration
Max Hold / Min Hold Setup
Source 1
Reset Source
IM/CM/ED–EN Rev. B
1 1
/ and / DIN
4 2
The source of the first operand in the equation (any analog or digital signal or user-defined
constant).
Sets the constant value to be used.
Note. Applicable only if Source 1 is assigned to one of the constants.
Terminates the equation.
Standard arithmetic functions.
Result is the lower of the 2 operands.
Result is the higher of the 2 operands.
If Median operators are used the median value calculated is dependent on the number of
operands:

The median value of 2 operands is their mean value.

The median value of 3 operands is the value of the middle operand when the
operands are sorted in ascending order.

The median value of 4 operands is the mean value of the 2
the 4 operands are sorted in ascending order.
Selects the source for real time average value calculation – see Appendix A, page 79 for
description of sources.
Selects the digital source required to reset the internal accumulative value and timer.
This does not change the immediate output of the math block but restarts the calculation of
the next average value.
Sets the time duration the average is to be calculated over.
The output value of the math block is updated at this rate.
Selects the source for maximum / minimum value calculation – see Appendix A, page 79 for
description of sources.
Select the digital signal to be used to reset the maximum or minimum value.
7 Advanced Level
nd rd
and 3 operands when
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