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ControlMaster CM30, CM50 and CMF310
Universal process controllers,
1
/
4
,
1
/
2
DIN and fieldmount
7 Advanced Level
IM/CM/ED–EN Rev. X
77
…Functions
Math Blocks
Up to 8 math blocks can be configured. Each block can be configured as one of 6 different
types (see
Block Type
below). The resulting analog value can be used as a source for other
function blocks, for example,
Process Variable
in the
Custom Config
parameter – see page
36.
Math Block Number
The math block number (1 to 8).
Block Type
Selects the type of math block required.
Equation
(See page 78 for
Equation
setup.)
Enables an equation with up to 4 operands and 3 operators to be created. The operands
can be assigned to any analog or digital signal (see page 104). Digital signals have a value of
either '0' or '1'. With the exception of the Median operator, the equation is processed in a
strict left to right order, with no operator precedence.
The result of a math block can be used as the operand in another math block, enabling more
complex math equations to be constructed. The math blocks are processed in ascending
order;
Math block
1 is processed first, then
Math Block 2
, then 3 to 8.
Real Time
Average
(See page 78 for
Real Time Average
setup.)
Calculates the average value of a parameter over a user-configurable duration. The output of
the math block is updated at the end of the set duration only. A reset signal can be
configured to restart the calculation of the average value.
The average value is stored in case of power failure. If the duration of the power failure is
longer than the
Average Duration
(see page 78), the math block output value is set to zero.
Max Hold
Min Hold
(See page 78 for
Max Hold / Min Hold
setup.)
The math block output represents the highest / lowest value of the signal since it was reset.
Multiplexer
(See page 79 for
Multiplexer
setup.)
Enables 1 of 2 analog signals or constant values to be selected using a digital signal.
S
quare Root
(See page 79 for
Square Root
setup.)
Calculates the square root of the selected sources value. If the input is less than 0, the
output is set to zero and the math block output state set to invalid.
Operand 1
Operand 2
Operand 3
Operand 4
Operator 1
Add, Subtract
Multiply, Divide
Low Select
High Select
Operator 2
Add, Subtract
Multiply, Divide
Low Select
High Select
Add, Subtract
Multiply, Divide
Low Select
High Select
Operator 3
0
1
B
A
O/P
Select
Select
A
B
O/P