When Triggering is selected from the Data Collection dialog, Logger Pro waits for the user defined condition to be met prior to data collection. For example, you can have Logger Pro collect temperature data beginning only when the temperature raises (or falls to) to 35 degrees Celsius.
Triggering is only
accessible
when the collection mode is Time-Based.
When the Trigger
on Sensor Value
box is checked, you may set the parameters for the triggering of data
collection. You must select one sensor channel and condition. The data
collection will begin once the sensor reading increase or decrease
across a preset value or when a parameter (variable) is
met.
Pre-Trigger Data
You may also set the number of points to be collected before the trigger condition is met. A blank entry is equivalent to zero. Once you enter a number of Points Before Trigger, Logger Pro will confirm with a message within the dialog that the specified number of points must be collected before triggering can occur.
It is important to note that if a number of Points Before Trigger is entered, all those points must be collected before triggering can occur. If the trigger condition is met before the number of pre-trigger points can be collected, no data collection will take place.
Keyboard Triggering
Keyboard triggering offers a way to begin data collection immediately after pressing the spacebar or Enter key. While the spacebar can be used to start data collection in most cases, there is always a short setup time before data collection starts. With Keyboard Triggering, you click Collect, and the data begin streaming from the interface. When the spacebar or Enter key is pressed, the next point to arrive is the start of the collected data. This rapid start to data collection is most often useful in starting Motion Detector data collections. When you click the Collect button when Keyboard triggering is enabled, the message "Waiting for keyboard trigger..." will appear on the screen. Press Enter or space to start data collection.
Keyboard triggering requires data rates of 250 Hz or below, and is not needed for data rates below 2 Hz.