Campbell Scientific ID-2000W Software - Manual (Page 52)

SECTION 5. CALCULATED PARAMETERS
5-2
5.1 EDITING/CREATING
To create a new calculated parameter click the
“New” button which activates the “Name” edit
box. Use this box to enter the name for the new
calculated parameter.
There are restrictions on what you may name a
parameter. For detailed information on these
restrictions please refer to the chapter on
Importing. The following is a brief summary of
these restrictions:
•
It may be up to 15 characters in length.
•
It must start with a letter.
•
It must contain ONLY letters, numbers, and
the underscore character _.
•
It must NOT contain spaces.
•
It may consist of both upper and lower case
letters.
•
It may not be the same as one of ID-2000s
standard parameters (regardless of case):
•
It may not be the same as one of ID-2000
mathematical functions (regardless of case):
•
It may also be useful to use upper and
lower case character combinations for
parameter names as in EngineSpeed,
OilPressure, ExhaustTemp, etc.
To edit an existing calculated parameter in the
Existing Parameters list, highlight it and click the
“Edit” button. You may also double click the
parameter to edit it.
5.1.1 DELETING
To delete an existing calculated parameter in
the Existing Parameters list highlight it and click
the “Delete” button.
5.1.2 ENTERING AN EQUATION
Calculated parameter equations may contain
any parameter in the Existing Parameters list
including other calculated parameters,
mathematical operators, and/or mathematical
functions. The following is a sample equation
that uses parameters, operators, and
mathematical functions.
((TurbineSpeed^0.5)+Throttle/ABS(PressRatio))
*(ExhaustTemp/1080.98)^2
Equations must not exceed 180 characters in
length.
NOTE: If your equation is longer than 180
characters you may be able to break it up
into multiple sub equations and then
combine them together for a final calculated
parameter.
Equations are case sensitive. In the sample
equation above notice that some parameters
use both upper and lower case characters. You
must enter a parameter or math function
precisely or ID-2000 will report it as a missing
parameter.
Equations may use any of the standard math
operators:
•
+ Addition
•
- Subtraction
•
* Multiplication
•
/ Division
•
^ Raise to power
•
( ) Parenthesis
ID-2000 provides many mathematical functions
that may also be used in an equation. These
functions are listed on the following pages.
You can manually enter or modify the equation
using the Equation edit box. You may also
double click on any parameter in the Existing
Parameters list or Math Functions list which will
cause it to be pasted into the equation at the
current location.
When the equation is complete you may check
it for errors by clicking the “Check” button. If
any errors are found ID-2000 will display the
error so that you may correct the equation.
If errors such as ‘division by zero’ or ‘argument
too large’ occur during the calculation of a
calculated parameter, a message will be
displayed at the end of the process identifying