The LMS Test.Lab Time Signal Calculator is loaded with functions to condition and perform calculations on time files.
Operations include filtering, integration, envelopes, rosette, math, logic operations and more!
To turn it on, choose “Tools -> Add-ins -> Time Signal Calculator”.
Go to the “Time Data Selection” workbook and load up some time history data:
The time data is now available for processing.
Note the following about the time data list:
Formulas can be entered in the Time Signal Calculator to manipulate data in the list.
When creating formulas in the Time Signal Calculator, there are three key fields that can be filled out:
Once channels are loaded, notice that they are assigned identifications, for example, CH1, CH3, etc. CH is short for Channel.
The math operations ( +, -, /, * ) can be used with these identifications.
When doing these operations, it is not necessary to use the assigned channel identification. Instead, one can use the Point Identification:
The desired engineering unit can be assigned to the result of any math operation. Use the bracket signs to assign the unit, for example [g]
To ensure the data is handled properly, the assigned unit needs to be a valid unit that exists in the LMS Test.Lab Unit system. If you are not certain what units are valid, go to “Start -> Programs -> LMS Configuration and Unit System…” to get the available list. Note that the units are case-sensitive.
There will be a warning if the unit specified is not available/valid, and the status on the formula will be colored red.
Create additional cells for formula using F key with a yellow star. There is no limit to the number of formulas. You can also delete the formulas using the F key with a red X.
To save formula sets and recall them for later, use the buttons.
In addition to math functions, many other operations can be performed on time data. To access the other functions, highlight the cell for which to create the functions and press the button with “f(x)” showing on it.
A list of functions appears. The left side of the menu are categories for the functions, while the right side is the list of individual functions.
As an example, to create a high pass filter, select the FILTER_HP function.
For a filter function, the following can be filled in:
Information about these fields are found in the software help.
Press “OK” when finished.
To perform the filtering operation, press the “Calculate” button to perform all functions in the list. “Calculate Selected” can be used to perform only the highlighted function.
Other popular processing functions include:
Sometimes the same operation may need to be performed on multiple channels. However, it is not necessary to create 20 separate FILTER_HP functions to filter 20 channels. This can be done in one step.
Here is how:
Note that the “Repeat for…” field may require using the slider bar in the lower left corner to scroll over to see the field. It may not be visible by default.
Questions? Contact us!
LMS Test.Lab acquisition tips:
LMS Test.Lab Display Tips: