Fluke NetDAQ 2645A - Manual (Page 115)

Configuring NetDAQ Logger for Windows
Configuring Channels
3
3-21
3. If the equation contains an error, an error message appears. Click OK in the
error message box. If possible, NetDAQ Logger highlights the location of the
error in the equation. Change the equation as necessary and click OK to return
to the Channels Configuration dialog box.
4. Click OK to return to the Instrument Configuration dialog box.
5. If all of the defined equations for this instrument exceed the allowed storage
space (1000 bytes), an error message appears. If this happens, reopen the
Functions dialog box and redefine or eliminate equations as necessary.
Equation Syntax 3-28.
Use the following guidelines to define new equations or modify existing ones.
Each equation can be up to 100 characters in length, and each must include a
reference to at least one other configured channel. Examples of equations are
shown below:
(-2*c21/c2)/(2*(1.32-(c21/c2)*1.32))
20 * log(C1/C2)
Operands can be integer or real constants, or analog or computed channels. Each
channel reference contains the letter ‘c’ followed by a one-or-two-digit channel
number. All referenced channel numbers must be lower-numbered than the
channel being defined.
Examples of operands are shown below. (The decimal point character corresponds
to your Windows International settings.)
1.5e5 c21
-32.407 C1
2.57E-3 c02
Operations are computations or functions performed on the operands. Refer to the
allowed operations below, shown in order of increasing precedence. Operators in
the same row have the same precedence.
+ -
* /
**
unary +
unary - abs exp int ln log sqr
Delimiting the argument of a function requires parentheses. Use them also to
enforce, override, or clarify precedence. You may nest up to three sets of
parentheses. The following examples demonstrate proper and improper use of
nested parentheses: