Agilent Technologies InfiniiVision 3000 X- Series, Advanced Training Manual, Page: 94 / 128

94 3000 X-Series Oscilloscopes Advanced Training Guide
4
Serial Bus Decoding & Triggering, Search & Navigation, and Segmented Acquisition Labs
You should now see on your scope’s display what appears to be an
un- triggered display of a digital burst signal similar to
Figure 67 . Your
scope is actually triggering on random rising edges of channel- 1, which is
the scope’s default trigger condition. But this signal is too complex to
establish a unique trigger point using simple edge triggering. This signal is
a packet/frame of CAN serial bus traffic. Let’s first set up the scope to
intelligently decode this data stream based on the CAN protocol, and then
we will establish a more unique trigger point using CAN triggering.
9 Press the
[Serial]
front panel key.
10 Press the
Mode I
2
C
softkey; then select the
CAN
serial decode mode using
the Entry knob.
11
Press the Signals softkey; then select CAN_L .
12
With the Signals menu active, also verify that the input Source is
defined as channel- 1 and the baud rate is set to
125 kb/s
(default
conditions).
You should now see CAN decoding of this signal on your scope’s display
similar to
Figure 68 , but we still haven’t established stable triggering. The
scope is still triggering on any rising edge of channel- 1 (default trigger
condition). Let’s now set up the scope to trigger on a CAN data frame
with the ID = 07F
HEX
.
13 Press the
[Trigger]
front panel key.
14 Select
Serial 1 (CAN)
using the Entry knob.
Figure 68 Decoding a CAN bus while triggering on any rising edge of the input signal.