Chauvin arnoux Metrix hx0074 User manual

EN - User’s manual

Signal generator circuit

HX0074 demo kit for

DOX2xxx and DOX2xxxB

Demonstration GX1025 with

DOX2xxx and DOX2xxxB

CONTENTS

GENERAL DESCRIPTION ...................................................................................................................................................................................3

PRESENTATION OF THE HX0074 ......................................................................................................................................................................3

I. TEST SIGNAL HX0074 .....................................................................................................................................................................................4

1. MISCELLANEOUS............................................................................................................................................................................................4

2. HYSTERESIS ....................................................................................................................................................................................................5

3. PULSE TRAIN ...................................................................................................................................................................................................7

4. DATA + CS TRAIN.............................................................................................................................................................................................8

5. DATA FRAME-FAULT .....................................................................................................................................................................................10

6. AMPLITUDE-MODULATED SINE WAVE......................................................................................................................................................12

7. SQUARE WAVE-RISE TIME ..........................................................................................................................................................................13

8. SQUARE WAVE - LOW LEVEL - NOISY ......................................................................................................................................................14

9. COMB OF RAPID PULSES............................................................................................................................................................................15

10. DIGITAL FRAME + FAULT ...........................................................................................................................................................................16

11. FRAME + RARE PULSE...............................................................................................................................................................................17

12. RECORDER-5 SIGNALS..............................................................................................................................................................................18

13. HEART RECORDER.....................................................................................................................................................................................20

14. HARMONICS .................................................................................................................................................................................................21

15. DISTORTION .................................................................................................................................................................................................22

II. DEMONSTRATION GX1025 WITH DOX2000..............................................................................................................................................23

1. USING THE GX1025 GENERATOR TO DEMONSTRATE THE ADVANTAGES OF THE “LONGMEM” MEMORY DEPTH AND

OF THE DIGITAL FILTERS ............................................................................................................................................................................23

1.1. Inuence of memory depth (LongMem or Normal) on the sampling interval:........................................................................................23

2. USING THE DIGITAL FILTERS .....................................................................................................................................................................24

2.1. 2 kHz square wave with a 62 kHz sine wave superposed on its plateaus ............................................................................................24

3. SUM OF 2 SINUSOIDAL SIGNALS HAVING FREQUENCIES OF 10 KHZ AND 80 KHZ........................................................................26

3.1. Display of the sum of 10 kHz and 80 kHz sine waves...........................................................................................................................26

4. PRODUCT OF 2 SINE WAVES HAVING FREQUENCIES OF 100 KHZ AND 800 KHZ............................................................................28

4.1. Display of the product signal with Delayed time base ...........................................................................................................................28

5. PRODUCT OF 2 SINUSOIDAL SIGNALS HAVING FREQUENCIES OF 10 KHZ AND 80 KHZ..............................................................30

5.1. Display of the product signal with Delayed time base ...........................................................................................................................30

GENERAL DESCRIPTION

The HX0074 is an accessory with a circuit the generates 15 representative signals. It is associated with a guide describing the nature of the signals.

The HX0074 demonstrator makes mastering the oscilloscope faster, because the display, analysis, and measurement of the signals generated

by the HX0074 make use of all functions of the DOX2000.

We will also use a GX1025 arbitrary generator to generate the signals specic to demonstrating the advantages of «LongMem» long recording

memory depths and of using digital lters to observe composite signals.

PRESENTATION OF THE HX0074

The HX0074 is built around a microprocessor. An LCD display unit and «UP/DOWN» buttons are used to select the desired signal. The HX0074

generates the signals on the «MAIN» and «AUX» BNCs.

The HX0074 can be powered:

- either by a standard 9 V battery

- or by a 12 VDC, 200 mA external mains adapter, with positive polarity, that of METRIX MTX Mobile multimeters, for

example.

The power supply mode is selected using the switch.

I. TEST SIGNAL HX0074

1. MISCELLANEOUS

Demo: with: DOX2025 DOX2040 DOX2100 DOX2xxxB

Test signal n°1 : Miscellaneous

Nature 4 pairs of successive signals approx. every 2 seconds.

Specs 2.6 V < Vpp < 3.2 V - 10 Hz < F < 60 Hz

Oscilloscope Settings 50 ms/div. - MAIN = CH1 = 1 V/div. - AUX = CH2 = 1 V/div.

Trigger standard on CH1 = MAIN

Modes XY (Display menu)

Objective Start in a playful manner by describing the di󰀨erent display modes:

Normal, Delayed, XY

a) Adjust the oscilloscope so as to display the signals correctly (possible using the «Autoset» key).

When Autoset is exited, the oscilloscope adjusts the vertical position so that the traces are not superposed.

b) Apply the “Delayed” and “ON” “OFF” commands in succession to be able to observe a complete trace and zoom on detail.

c) Select the «XY mode» with CH1 on X and CH2 on Y. Observe that there is a succession of 4 geometrical shapes.

The geometrical shape obtained in XY depends on the sampling rate, which in our example is Fsample = 50 kHz.

2. HYSTERESIS

Demo: with: DOX2025 DOX2040 DOX2100 DOX2xxxB

Test Signal n°2 : Hysteresis

Nature 2 phase-shi󰀨ed signals, triangle and pseudo-square

Specs Vpp ≈ 3.2 V - F ≈ 1.7 kHz - square wave ≈ 24 µs - signal delay ≈ 40 µs

Oscilloscope Settings 100 µs/div. - CH1 = MAIN = 500 mV/div. - CH2 = AUX = 500 mV/div.

Trigger standard on MAIN

Modes XY (Display menu) - no «Min/Max», and no «Repetitive Signal» (Horizontal menu)

Objectives

«y(t)» and «XY» modes from phase-shi󰀨ed signals

Present automatic measurements with markers (F, square-wave Tr)

Present phase measurements (manual, automatic)

Present the FFT Mathematical function

a) Adjust the oscilloscope so as to display the signals correctly (possible using the «Autoset» key) and select automatic phase measurement to

determine the phase di󰀨erence between the signals Main = CH1 and Aux = CH2.

b) Select the XY mode with CH1 on X and CH2 on Y.

The display of a hysteresis cycle is a “textbook case” often encountered in the educational context. It demonstrates the utility of display in the y(t)

and XY mode(s), respectively.

Stress the simplicity of access to the XY mode, and of access to automatic phase measurement.

c) Return to «y(t) mode» in order to demonstrate the use of the automatic measurements. (Ex.: Vpp, Vamp, Feq, Rise, ...).

d) Use of the FFT Mathematical function.

The oscilloscope displays the CH1 signal and its FFT simultaneous. The “Time” cursors can be used to determine the frequencies of the fundamental

and of the harmonics:

The “Voltage” cursors can be used to determine the amplitude of the harmonics:

FFT of the signal on channel CH2 :

3. PULSE TRAIN

Demo: with: DOX2025 DOX2040 DOX2100 DOX2xxxB

Test Signal n°3 : Pulse train

Nature 1 signal containing trains of 10 pulses with variable spacing

Specs Vpp ≈ 3.4 V - F ≈ 32 kHz - Train spacings ≈ 100 to 180 µs

Oscilloscope Settings 100 µs/div. - CH1 = MAIN = 500 mV/div

Trigger on CH1 = MAIN - Hold-O󰀨 ≈ 354 µs

Modes Triggered mode preferable

Objective Triggering with «Hold-O󰀨» on pulse trains

a) Adjust the oscilloscope to display the signal on CH1 correctly (time base, sensitivity, and triggering source).

Attention, with this type of signal, “Autoset” operation may be aleatory.

Without “Hold-Off”, the triggering may act on any pulse of the train, as soon as the oscilloscope is ready to acquire. This is

accompanied by a feeling of “horizontal instability”, making the display unusable. The proper setting of the “Hold-O󰀨” parameter (in the “Triggering”

menu  “Set”) serves to ensure systematic triggering on the first pulse of the train.

This value must be greater than the duration of the pulse train, to disable triggering during this period, but must remain shorter than the time between

2 pulse trains (which varies between 400 and 480 µs). In our case, the “Hold-O󰀨” must be between 300 and 400 µs.

b) Denition of the mask of the “Pass/Fail” function. “Utility”  Pass/Fail  Mask Cong  Mask Generation

c) Activation of the Pass/Fail function

The Pass/Fail function displays the number of times that the signal has satised (“Pass”) or not satised (“Fail”) the mask dened.

4. DATA + CS TRAIN

Demo: with: DOX2025 DOX2040 DOX2100 DOX2xxxB

Test Signal n°4 : Data + CS train

Nature 2 signals representing a digital frame (data) and a CS (chip select)

Specs Vpp ≈ 3.4 V - F ≈ 40 kHz (data) - F ≈ 1.5 kHz (CS)

Oscilloscope Settings 100 µs/div. - MAIN = 1 V/div. - AUX ≈ 1 V/div.

Trigger on BNC AUX = CH2

Modes Triggered mode preferable

Objective Triggering on pulses

a) Adjust the oscilloscope to display simply the 2 signals (time base, sensitivities and triggering source on the BNC AUX = CH2).

Attention, with this type of signal, “Autoset” operation may be aleatory.

b) We are now going to demonstrate the utility of the pulse width triggers. The example chosen will serve to synchronize to the chip select signal

of the data frame. We are going to trigger by turns on the width of the high level, then of the low level, of the “positive” pulse. In the rst case,

triggering will be on the negative-going edge of the chip select and in the second case it will be on the positive-going edge.

c) Observe the rst data group after the negative-going edge of the chip select using the “Delayed” function.

Example: to display the 2nd group of pulses, we shift the window by acting on the horizontal position.

Expansion by 25

Expansion by 100

Horizontal displacement of the Zoomed zone by acting on the “Position” encoder:

5. DATA FRAME-FAULT

Demo: with: DOX2025 DOX2040 DOX2100 DOX2xxxB

Test Signal n°5 : Data frame-Fault

Nature 2 signals representing a communication bus with «clock» and «data»

Specs Vpp ≈ 3.4 V - F ≈ 31 kHz (clock) - 30 µs < L+ < 200 µs (data)

Oscilloscope Settings 25 µs/div. - MAIN = 1 V/div. - AUX ≈ 1 V/div.

Trigger on MAIN

Modes Triggered mode preferable - SPO mode, duration ≥ 2 s

Objectives Capture and observe a rare event using SPO

Triggering on pulse width of the AUX signal

a) Adjust the oscilloscope so as to display the 2 signals in LongMem mode (time base, sensitivities, triggering source on MAIN).

Attention, with this type of signal, “Autoset” operation may be aleatory.

b) Observe a clock and the data bus using the “LongMem” function and the horizontal “Zoom”.

The proposed signal is representative of a communication bus with “data - 8 bits” and a clock.

This communication setup is found in particular with the protocols of serial links such as the I2C bus, USB bus, CAN bus, Ethernet communication, etc.

The rst utility of the operating mode is to detect and study faults in signals, without knowing their nature in advance, and therefore without having

to set specic triggering conditions, for example.

In our example, we have frames approximately 3 ms apart and 1 frame in 120, or one frame every 360 ms, with the data at zero.

In STOP, using the horizontal zoom (x 50) and choosing the position of the zoomed window, we can observe and analyse this frame and the one

just before it and the one just after it.

Then, with the x 1000 zoom factor, we observe the 6 clock pulses of the frame of zeros.