Measurement Computing LogBook Series - Manual (Page 163)

Software Reference 989592 LogView LV-37
Note: Calculated channels can have numeric values such as analog channel values. Calculated channels
can also have digital values of 0 or 1. These channels can be stored in any one (or all 4) timebases
set up in the Acquisition Configuration Window, in the same manner as other input channels.
User Input Box Equation Add New Cut Paste
(Appears as needed) Assistant Channel
Calculated Channel Configuration Windows with Calculation Function Examples
You can access the Calculated Channel Configuration window from the control window’s View pull-down
menu, or by using the Calc (fx) button. The window contains several columns that are easy to understand
because of their labels, and their similarity to columns previously discussed. The Calculation Function
column is a noted exception that is explained via the following four examples.
Note: Channel ID and Physical Channel nomenclature appear in the Calculation Function column. User
Labels will not appear in the function column unless they are identical to a Channel ID, or a
Physical Channel label.
Refer to the above screen shots for the examples which follow.
In addition to understanding the equation aspect of the following examples, you should
also note the differences between the two types of configuration screens; i.e., an actual
(real) channel and the calculated (virtual) channel.
Reference Note: You may wish to refer to math or programming books to derive calculation
functions that suit your specific application.
Equation Assistant
The following window is opened by the F(x) button on the Calculated Channel Configuration window.
The Equation assistant helps to ensure that the proper syntax is used in the Calculation Function column.
Selecting the corresponding math and logic operators will enter the corresponding commands (these
commands can also be typed in, but using the equation assistant can minimize syntax mistakes).
No recursion. A calculated channel cannot refer to itself directly or indirectly by
creating a loop of inter-related calculations.