Explanation Of Computing Equations - Omega RD-MV100 Series User Manual

11.2 Explanation of Computing Equations

Four Arithmetical Computations
Power, SQR, ABS, LOG, EXP Computations
11-4
This section describes the meaning of the computation equation and how to write them.
The types of data that can be used in equations are measurement channels,
computation channels, constants (K01 to K12), communication interface data (C01 to
C12), and the remote control terminal conditions (D01 to D08).
EXAMPLE :
Addition (+) : 01+02
Computes the value of channel 1 plus the value of channel 2
Subtraction (–) : 01-02
Computes the value of channel 1 minus the value of channel 2
Multiplication ( ) : 01 K03
Computes the value of channel 1 multiplied by constant number 3
Division (/) : 01/K02
Computes the value of channel 1 divided by constant number 2
Note
When you set an expression as e.g. 31 = 31 + 01, the summation of channel number 1 will be
displayed in channel 31.
The types of data that can be used in equations are measurement channels,
computation channels, constants (K01 to K12), communication interface data (C01 to
C12), and the remote control terminal conditions (D01 to D08). You can nest a
computing element inside the parentheses of another computing element.
EXAMPLE :
Power ( ) : 01 02
Raises measured value of channel 1 to the power of measured value of channel 2
Square root (SQR) : SQR (01)
Returns the square root of the measured value of channel 1
Absolute value (ABS) : ABS (01)
Returns the absolute value of the measured value of channel 1
Logarithm (LOG) : LOG (01)
Returns the common logarithm of the measured value of channel 1
Exponent (EXP) : EXP (01)
Raises e to the power of the measured value of channel 1
Note
The natural logarithm is not directly provided, but can be obtained by using the following :
log x = log x/log b or lnx = logx/loge
b a a
Therefore, to calculate the natural logarithm of the value of channel 01, set K01 = 1.
Then the expression will become : LOG (01)/LOG (EXP(K01))