User manual

CANbus Trigger, Decode, and Measure
40
CANbus-TD-TDM-OM-E RevB
Acquisition dead time is kept to a minimum because there are no operations performed during
the acquisition. All data for each triggered event is written only into high-speed acquisition
memory. Until the entire sequence is completed, there is no updating of the oscilloscope
display, or other operations that cause unnecessary dead time. This is ideal for situations when
you cannot take a chance on losing data.
In the example shown below, we have only acquired Channel 1 (the CAN signal) in sequence
mode. We could also acquire additional analog or other signals as desired or as necessary to do
a proper analysis.
1. Touch the Timebase descriptor box to open the Timebase dialog.
2. In the Sampling Mode area, select Sequence Mode. Touch the Sequence tab.
3. On the Sequence tab, select the Display Mode. Select the Number of Segments Displayed
at one time.
4. If you have acquired more segments than you can display at one time, you can choose
the segment at which to start the display.
5. Set up the Serial Trigger to capture an event. For instance, you might want to trigger on a
specific address or data value, and capture long pre-trigger time to determine what
precedes that message. In this example, we’ve used a simple I2C Start trigger. To begin
the sequence mode acquisition, press the front panel SINGLE trigger button. Each time
the trigger condition is met, the TRIG’D light on the front panel flashes. When you’ve
acquired the set number of segments, the trigger STOPS and the following display is
shown (this is a 50 segment acquisition in Mosaic display mode).