No. 5 : Data Frame - Fault - Metrix HX0074 Guia Del Usuario

Demo: with:
Test Signal
Specs
Scope Settings
Trigger
Modes
Purposes
a) Calibrate the Oscilloscope so as to view the 2 signals correctly (timebase, sensitivity and trigger source on
MAIN).
Important: for this signal type using Autoset may not be useful.
b) Select "SPO Persistence" in the display menu and set a duration of ≥ 2 s.
The main interest of the SPO acquisition and display mode is to enable the detection and study of faults on
signals without prior knowledge of their nature, and without having to calibrate specific triggering conditions, for
example.
Then, due to its very high acquisition rate in relation to a conventional Digital Oscilloscope (up to 50,000 per
second rather than around 10 per second) it enables us to reveal and capture rare or complex events much
more efficiently.
Lastly, the intelligent display algorithm enables a much richer and more faithful display of the whole content of
the Oscilloscope memory, even if this largely exceeds the intrinsic possibilities of a standard ¼ VGA screen due
to its resolution capabilities (only 250 pixels across for the trace zone).
c) Triggering on AUX signal pulse width (demonstration possible on all three Oscilloscope ranges).
24 - Chapter II
MTX3x5x SPO OX 6000 c)
& MTX105x SPO
OX 6000-II c)

no. 5 : Data frame - Fault

Type 2 signals from a communication bus with "clock" & "data"
Vpp ≈ 3.4 V - F ≈ 31 kHz (clock) - 30 µs < L+ < 200 µs (data)
20 ou 25 µs/div. - MAIN = 1 V/div. - AUX = 1 V/div.
Triggered mode preferred, SPO duration mode ≥ 2 s
Capture and observe a rare event using SPO
Triggering on pulse width of AUX signal
The proposed signal represents a communication bus with an
"8-bit data" signal and a "clock" signal.
This communication set-up is often found in serial connection
protocols such as I2C bus, USB bus or CAN bus devices,
Ethernet link, etc.
The intelligent SPO (Smart Persistence Oscilloscope) display
reveals rare or complex events that are not visible in Envelope
mode.
Example: synchronisation fault, overshoot, glitch, erroneous bit
or analogue characteristic problems.
In normal "Oscilloscope" display mode, select to trigger on the
AUX signal pulse width ("Trigger" menu - "Pulse" tab).
Successively change the value so as to trigger on the different
periods (32, 64, 96, 128, 160, 192µs, etc.), by using the
operators "<", "=" or ">".
SCOPIX
c)
on MAIN, pre-trigger ≈ 1 division
METRIX Oscilloscope Demo Kit
HANDSCOPE