The following knowledge base provides instructions on how to start, pause, and stop a logger using a relative x-axis
The following logger configuration should have the following properties:
- The logger should be able to be started via the dashboard.
- The recording should be able to be paused and resumed via the dashboard.
- The logger should be able to be stopped via the dashboard, so that the measurement file is finalized and a new one can be started.
- The complete measurement file should be visualized as a continuous measurement series.
The following 3 steps are necessary:
- Creating the required virtual variables.
- Setting up the data logger.
- The exact functionality will be described in the last point.
Step 1) Required Virtual Variables
Four additional virtual variables are needed for the logger:
- Logger_StartStop: Used to start and pause the logger.
- X_Axis: Used to generate a new x-axis without a timestamp, so that the measurement data can be displayed continuously.
- LoggerState: Returns to 1 when the logger is recording.
- LoggerEnable: If the logger is armed, this variable returns to 1.
Step 2) Setting up the Data Logger
An event-based logger is required for the implementation of the logger.
When selecting the variables, the signals to be recorded are chosen, along with the variable X_Axis created under the virtual variables.
The above settings show a possible configuration. It is mandatory to use the logger type "Event based." The file length and event length can be adjusted to meet the requirements. In the example, the minimum event length is 10 seconds.
The other important settings are configured in the "Trigger" section.
The trigger must be activated and set to "Every Threshold" mode. This option triggers the event every time the trigger condition is met. With the "Single Shot" setting, the trigger condition would first have to fall back before it can trigger a new event. For the pause and resume functionality, the "Every Threshold" mode is absolutely necessary.
Step 3) Functionality
The following dashboard will explain the functionality in more detail.
In the bottom right, the logger is displayed using the Data Logger Widget. The logger is currently stopped. When clicking the red button, the logger is armed. It is important to note that if a measurement series name and metadata are to be used, this information must be entered before arming, as the information is written into the measurement file when arming occurs.
In the bottom left, the logger can be started (only if it has been armed) or paused. When the logger is armed and started, the X_Axis variable (displayed at the top right) begins counting up. When paused—by setting Logger_StartStop back to 0—the counter freezes. As soon as Logger_StartStop is set back to 1, the X_Axis variable continues counting. When the logger is stopped, this variable is reset to 0, the measurement file is completed, and the logger is prepared for the next measurement run, regardless of the file length set in the logger settings.
