Yokogawa Data Acquisition with PID Control CX2000 - Manual (Page 375)

App-6
IM 04L31A01-01E
Appendix 2 Supplementary Explanation of the
Computation Function
This section explains in detail the computation function. It is a supplement to the
information covered in “Computation Function” in section 1.18, “Computation and Report
Functions (Option).” For a description on how to create equations, see appendix 3,
“Meaning and Syntax of Equations.”
Channel Number to Which the Computation Results Can Be Assigned
The computed results can be assigned to channel numbers [31] to [60]. By selecting
these channel numbers on the trend display, you can check the computed results by
viewing the trend.
Types of Computations
In the table below, y represents the computed result. X and n represent the measured
data of a measurement channel and a constant. For details, see “Data That Can Be
Used in Equations.”
Type Syntax in the Equation Description
Four arithmetic operation +, –, *, / Determines addition, subtraction,
multiplication, and division.
Power ** Determines the power. y = X n
Square root SQR() Determines the square root.
Absolute value ABS() Determines the absolute value.
Common logarithm LOG() Determines the common logarithm. y = log
10
x
Exponent EXP() Determines the exponent. y = e x
Relational computation .LT., .LE., .GT., .GE., Determines <, ≤, >, ≥, =, or ≠ of two
.EQ., .NE. elements and outputs “0” or “1.”
Logical computation AND, OR, XOR, NOT Determines the AND (logical product), OR
(logical sum), XOR (exclusive logical sum)
of two elements, NOT (negation) of an
element and outputs “0” or “1.”
Statistical Computation TLOG.SUM(), TLOG.MAX(), Determines the sum (SUM), maximum
TLOG.MIN(), TLOGAVE(),
(MAX), minimum (MIN), average (AVE),
TLOG.P-P(), and maximum – minimum (P-P) at specified
time intervals.
There are three timers for setting the
interval.
Statistical computation CLOG.MAX(), CLOG.MIN() Determines the maximum (MAX), minimum
(control) CLOG.AVE(). CLOG.P-P() (MIN), average (AVE), and the difference in
the max and min values (P-P) of data
measured at the same time.
Conditional expression [eq1?eq2: eq3] If the result of eq1 is not 0, eq2 is
(control) computed, or if the result of eq1 is 0,
equation 3 is computed. If eq1's
computation results in an error, a
computation error occurs.