LJlogger sends and receives data in command/response mode by making 2 DLL calls to “AISample” and 1 DLL call to “AOUpdate”. It is capable of logging data to disk (2 Hz max) and performing various actions on trigger events.
The first column in the data file is a timestamp of seconds since midnight January 1st (Universal Time), 1904. The default time format in Microsoft Excel and Open Office Calc is days since 1900, so to convert divide by 86400 (seconds/day) and add 1462 (days from 1900 to 1904). To convert from Universal Time to local time, subtract the difference in days, so for Colorado, USA, we would subtract -0.291666667 (7 hours divided by 24 hours/day).
The main window for LJlogger is shown in Figure 3.4-1. The white colored items and the “SDX” buttons are controls to be edited/selected by the user. The grey colored items are indicators which display various information about the LabJack. Clicking the button labeled “Save Panel Settings” will save the current values of the controls as the default values.
If SDX is activated for a given analog input, the corresponding SDX DLL will be used to determine the scaled data. Users can make their own SDX DLLs (see the source code for more information), to provide more complex scaling or scaling that depends on other analog inputs.
Clicking the “Configure” button shown in Figure 3.4-1 brings up the window shown in Figure 3.4-2:
Clicking on the “Internet Setup” button in Figure 3.4-2 brings up the Internet configuration window shown in Figure 3.4-3. Basic customization of the HTML file can be done by clicking on “Advanced HTML Configuration” which brings up Figure 3.4-4.
Clicking on the “Trigger Setup” button in Figure 3.4-2 brings up the window shown in Figure 3.4-5.
Figure 3-9 shows 9 example triggers: