There are several different types of trigger conditions:
Edge trigger can be used to trigger on a rising edge (or slope) or a falling edge in the signal. Which edge is being triggered on, can be selected.
To trigger on an edge, the system has two adjustable levels, the arming level and the firing level. The trigger system will constantly compare the input signal with the two levels.
As soon as the input signal passes the arming level in the specified direction, the trigger system is "armed" and ready to detect a passing of the firing level. When triggering on a rising edge, the arming level must be passed in an upward direction, so the signal must first be smaller than the arming level and then become larger than the arming level. When triggering on a falling edge, the arming level must be passed in a downward direction, so the signal must first be larger than the arming level and then become smaller than the arming level.
When the input signal passes the firing level in the specified direction and the the trigger system is armed, the required edge is found, the trigger condition is met and a trigger signal is generated ("fired"). When the input signal passes the firing level but is not armed, nothing happens and the system will continue monitoring the input signals.
In the image below, rising edge triggering is shown. For falling edge triggering, the firing level and arming level will be swapped.
Window trigger can be used to trigger when the input signal enters a window or leaves a window.
To trigger based on a window, the system has an adjustable window of which the upper and lower level can be adjusted individually. The trigger system will constantly compare the input signal with the upper and lower level of the window.
When using Outside window triggering, the system will generate a trigger as soon as the signal becomes larger than the upper level of the window or smaller than the lower level of the window, in other words: is outside the window.
When using Inside window triggering, the system will generate a trigger as soon as the signal becomes larger than the lower level of the window and smaller than the upper level of the window, in other words: is inside the window.
In the software, the upper level is controlled by the trigger level. The position of the lower level is controlled by the trigger level and the size of the trigger hysteresis.
In the image below, Outside window triggering is shown.
An image on a TV screen consists of a number of horizontal lines. All these lines are transmitted to the TV one after another. To reduce flickering, first all even numbered lines are transmitted, and then all odd numbered lines. This is called interlacing. So one image is built of two frames with lines.
To make sure that the TV receiver reconstructs the image in the correct way, there are line synchronization pulses between all lines and frame synchronization pulses between the different frames. The frame sync pulse after an odd numbered frame is different from the frame sync pulse after an even numbered frame.
Some of the TiePie engineering instruments have special sync pulse separator circuits, that will detect the TV line and frame pulses in a TV signal. These pulses can be used to trigger the measurement, so that a measurement will always start at the beginning of a line, or at the beginning of the even frame or at the beginning of the odd frame.
The options to choose from in the software are:
Changing the trigger type of a channel in the Multi Channel software can be done in various different ways: