Technical data

Serial Bus Decoding & Triggering, Search & Navigation, and Segmented Acquisition Labs 4
4000 X-Series Oscilloscopes Advanced Training Guide 125
Lab #21: Decoding, Triggering, and Searching on FlexRay Serial Bus
Signals
In this lab you will learn how to set up the scope to decode and trigger on
FlexRay serial bus traffic. In addition, you will learn how to use the
scope's automatic FlexRay Search & Navigation capability, as well as use
Segmented Memory acquisition to capture multiple and consecutive
occurrences of a particular operation. This lab does not provide a tutorial
on the FlexRay protocol and signaling. Also, the FlexRay signal provided is
not a complex representation of true FlexRay traffic; while most FlexRay
implementations may have dozens of static slots and dozens of cycles, our
training signal will consist of two slots and two cycles, for simplicity. To
complete this lab, your scope must be licensed with the FlexRay trigger
and analysis option (Option FLX). You can verify the installed options on
your oscilloscope at [Help] > About Oscilloscope.
1 Connect the channel-1 probe to the Demo 1 terminal and ground.
2 Press [Default Setup] on the scope's front panel.
3 Press [Help]; then tap the Training Signals softkey.
4 Select and enable the FlexRay signal.
5 Set channel- 1 to 500 mV/div.
6 Rotate the trigger level knob to set the trigger level to approximately
-300 mV. This is the standard trigger level for FlexRay signals.
7 Set the scope's timebase to 2.0 µs/div.
You should see on your scope's display what appears to be an un- triggered
display similar to Figure 84. Your scope is actually triggering on random
rising edges of channel- 1, which is the scope's default trigger condition.
But these signals are too complex to establish a unique trigger point using
simple edge triggering. Let's first set up the scope to intelligently decode
this data stream based on the FlexRay protocol, and then we will establish
a more unique trigger point using FlexRay triggering.