DC oscilloscope measurement

My circuit works well with sine waveform. But why doesn't it work with DC input? What is wrong with my circuit? Could you tell me?
Attachments:
Single channel Waveform+File.vi ‏72 KB

Do you mean I have to change the second item into Normal trigger. But it is Normal. I have tried in my device. It displays well in the AUTO(Untriggered Roll) Mode. I would like to know how to modify the circuit to meet this requirement.

Similar Messages

NI Oscilloscope Measurement Problem

I have a very different problem regarding NI-5102 Oscilloscope Card
Problem 1:
This card is performing self test through the measurement & automation explorer. But through its driver program its showing failed. As there is self test vi in niscope.llb. It should return 0 for passed,
but its returning 1.And also from front panel of this card, its working well.
Problem 2:
Through front Panel of Oscilloscope i am able to see all the wave and also measure frequency, But through program it not giving any value, may be some settings are necessary for this problem. So u see this problem or if possible, u send a simple vi program for measurement of frequency of any wave (TTL pulse, sine wave).
Waiting for your response,
J
itendra :: mail me [email protected]

Jitendra,
When running the niScope SelfTest.vi, you usually receive a message indicating that the device passed the test and you should also receive a number 0 in the test result indicator. If the board is not passing the test, make sure that no other programs are using the same device (like MAX or the Scope Soft Front Panel). Adding an niScope Error Handler after the niScope Close will help us have more information of what is happening. With the error code, you can then visit ni.com and look for any Knowledge Bases that talk about this issue in particular.
Regarding the second problem, there are some pretty good example programs on the web that show how to do frequency analysis using NI digitizers. I am including links to some of them. Hope this help
s!
Frequency Spectrum Analyzer for NI-SCOPE (NI 5911/NI 5112)
Frequency Response (step response method)
Annette Perez
Applications Engineering
National Instruments.

NI-5102 Oscilloscope Measurement Problem

Hi,
I have a very different problem regarding NI-5102 Oscilloscope Card.
Problem 1:
This card is performing self test through the measurement & automation explorer. But through its driver program its showing failed. As there is self test vi. It should return 0 for passed, but its returning 1.And also from front panel of this card, its working well.
Problem 2:
Through front Panel of Oscilloscope i am able to see all the wave and also measure frequency, But through program it not giving any value, may be some settings are necessary for this problem. So u see this problem or if possible, u send a simple vi program for
measurement of frequency of any wave (TTL pulse, sine wave).
Waiting for your response,
Jiten
dra ([email protected])

When running the niScope SelfTest.vi, you usually receive a message indicating that the device passed the test and you should also receive a number 0 in the test result indicator. If the board is not passing the test, make sure that no other programs are using the same device (like MAX or the Scope Soft Front Panel). Adding an niScope Error Handler after the niScope Close will help us have more information of what is happening. With the error code, you can then visit ni.com and look for any Knowledge Bases that talk about this issue in particular.
Regarding the second problem, there are some pretty good example programs on the web that show how to do frequency analysis using NI digitizers. I am including links to some of them. Hope this helps!
ef="http://zone.ni.com/devzone/explprog.nsf/6c163603265406328625682a006ed37d/7472892af9a5fd278625680...
Frequency Response (step response method)

Unstable Frequency Measurement USB6210

Hi All,
I'm struggling to get a stable frequency measurement, to measure the RPM of a motor, using a single counter on a USB6210 board.
I'm using the +5V TTL signal to power an opto-transistor, and reading that signal back through Ctr0 (PFI1). See attached wiring schematic.
I've put a scope in line (between PFI1 and DGND), and at the PFI1 terminal get a square wave, about 50Hz, peaks at about 2.5V. Do I need to be linking this signal to DGND, and how?
I've set up a task in MAX, and readings fluctuate from 45Hz to 900Hz.
I've also tried to read this in LabVIEW using the example VI - Meas Dig Frequency-Low Freq 1 Ctr.vi. I then get even more random results of +100,000 (full scale).
Many Thanks,
Martin
Attachments:
Counter Wiring.jpg ‏63 KB
24022010044.jpg ‏397 KB

thanks a lot John P, i'll try it this vi config.
well, my flow transmiter should give an 0-5 volts signal with frequency between 0 and 100 hz (datasheet here), and the data i need is codified in pulse frequency, the measured voltaje is wrong but frequency on oscilloscope is ok. i attached pics of my signal on oscilloscope measured on transmitter output, measures at daq card input are the same, i connected my transmitter ground to digital ground (im working on ni pci 6221).
i tried the Minimum Pulse Width option with 2.56 ms but now i realized why did'nt worked (voltaje level issues ), but now my typical noise is 3% of my signal, i think noise won't be a big deal.
and i was surprised too about this system could get data acquisition insteand of data timeout error (because of voltaje level's issues), at first test i performed the system made the measures already mentioned, but i realized the ones who made this system attached the signal acquisition line to waterpump's power source (in fact, they attatched all data signal's lines to waterpump's power source ¬¬) and they hid noise effects with waveform's settings, now i fixed this and the system only shows me data timeout error.
initially i got confused because if im getting frequency acquisition of milivolts signal i thought daq card's counter input could deal with it, but now i realized it was just noise peak effects.
best regards
.:. Pedro Rivera .:.
i love to work and develop on labview, this is real fun!!!
Attachments:
signal acquisition.zip ‏355 KB

This is what counts for support these days?

my post:
"sometimes the messaging app crashes. pic
sometimes a message gets received, but the light doesn't blink.
wifi disconnects and won't reconnect until i turn wifi off and then back on, or reboot the phone.
sometimes the walkman app just stays there, blank. pic
the contact list, while sorted, does not categorize by initial letter for greek names. They all appear under the category '#'
when playing sound, notifications, music, whatever, the playback is choppy. very choppy.
it plays for a fifth of a second, has a gap, then does a pop, another gap and finally continues with the sound. Especially when listening with headphones this is very annoying. Also dangerous, because no matter what level you've set the volume, the clicks and pops always are LOUDER than the maximum volume allowed. pic. Notice that the initial pop is 8 dB louder in one channel and more than 12 dB louder than the notification itself for the right channel.
especially the last one, i consider very important. If you are not convinced, i have more pics, recordings and oscilloscope measurements."
screenshots, measurements...
And the typical reply from the support forum:
"try to repair ur 4n.."
no "that's interesting, we'll look into it" no "do you have more measurements?" no "do this and give us the output so we have more information". nothing.
i just want to voice my frustration
if anyone in an appropriate position replies with something meaningful, i will eat my shoe.

johan
right now i am absolutely livid with all of you. I will explain why, later
Johan wrote:
I'm sorry to hear that.
this stance infuriates me even more. most of your responses are "we are 'sorry' you are having issues. have you tried a hard reset?" Do you know why on the show The IT Crowd, the 'solution' "have you tried turning it off and on again" is used as a running joke?
Could you post some examples of which characters you use that do not sort properly in the phone book and I will try to replicate this.
use the greek alphabet to insert them. they all appear under '#' in the phonebook. The forum does not allow me to write these characters in the post. why, i have no idea.
Do you use STAMINA mode? That can disable the notification LED for some applications.
no. It sometimes happens, sometimes not. As you can imagine, very difficult to observe.
Please share more information about the audio problems. Do you get this if the audio files is saved on internal memory or SD card, or both?
doesn't matter anymore. If you were following recent events you would have concluded that the pops and gaps i am referring to are a known issue. Supposedly fixed in 4.4.4.
About Wi-Fi. Do you experience this independent of router you've tried to connect to? Have you tried any router reboot or reset? Which network mode do you run, B,G,N? Which Wi-Fi channel do you use?
it fixes itself when i reboot the phone. take a guess what this means.
Try running Wi-Fi analyzer and set your router to the least occupied channel.
bad advice. for at least two reasons.one, you can't be sure that wifi analyzer will not interfere with the wifi driver in some way altering the results and two, under normal conditions the only channels that should be used are specific. IIRC 1 5 and 9.
also irrelevant because i tested it with the phone right next to the router's antenna. it's an issue with the driver.
So far the only times i know it has happened, is while watching youtube. It may have happened other times as well, but i can not now because from what i remember youtube is the only data intensive program i am using. I try to watch a video and it buffers all the time. I investigated and found that pinging the phone from elsewhere and pinging elsewhere from the phone exhibits the behaviour i showed in the pic. Turning wifi off and back on on the phone doesn't fix it. Rebooting the phone fixes it. Rebooting the phone every time this happens is not a viable workaround. changing the wifi protocol is not a viable workaround. Router can not be at fault, none of the other six devices (three laptops, two phones, one sbc) ever had an issue.
I'm sorry to hear that you feel like the you only get replies saying repairing the software, but its important to know that it can sometimes be the only option for fixing a problem.
i had already tried it. it's the first thing i try ever since the first android phone i had. It very rarely works. In fact, i do not remember the last time it worked. I asked a friend of mine, equally experienced, said he only once in his life had a problem go away with a hard reset, intermittent hard freezes with an xperia pro.

In VB6, why is the "GPIBNotify sub" (from the GPIBNotify AtiveX Ctrl) all the time called even if no Event happened? This callback function is started then stopped permanently as if its received SRQ from the GPIB Bus. Any ideas?

I'm programming in Visual Basic 6 to communicate between a computer and HP Measurement Devices (BER-Meter) with GPIB. I have already read information and code for this. My platform is W98. The NI488.2 commands can be sent without any problem between the equipements. However when I'm using the GPIBNotify ActiveX Control to use the callback function, there is a permanent starting and stop of the GpibNotify Sub. The SetupMask and RearmMask are set to RQS and the HP Device is well configured. Moreover an oscilloscope measuring the 10th line (SRQ
) of the bus didn't show any pulse on the line behalf the right one. Any Idea?

Hello-
So, the SRQ is not detected by the oscilloscope? It must be a setting that is not correct with the instrument. Try contacting the manufacturer of the instrument for details about SRQ's. The GPIBNotify ocx will not be able to react to an SRQ if there isn't one.
Randy Solomonson
Application Engineer
National Instruments

The precision of the timing analysis

In my project, I can get the timing analysis of the path "clk50M_PE2_ref to FPGA_TEST6". The "clk50M_PE2_ref" and "FPGA_TEST6" are the ports of FPGA. The path delay is 7.473ns from the timing analysis reports.
But when I measure these two ports signal with Oscilloscope, I get the delay time is 5.2ns. The testpoints are at the through-hole on the back of the FPGA (that is the bottom of the PCB).
Why the delay time is different between timing analysis and oscilloscope measurement? Which is the correct in fact?

yssy2000 wrote:
Thanks for your reply!
If I want to know the delay time from A ports to B ports, how to get the exactly value except with the oscilloscope?
That's like asking "how can I get the exact temperature at 2PM tomorrow except by waiting until then and using a thermometer?"
The tools can only predict the delay as a range, minimum to maximum, based on characterization data for your part. There are differences in delay from part to part (Process, the "P" in PVT), with variation in supply voltage (Voltage, the "V" in PVT) and with die temperature (Temperature, the "T" in PVT). You can use a scope or other measuring instrument to find the actual delay for a particular part at a particular voltage and temperature. Even so this delay may change for the same part and voltage supply due to changes in temperature. So the bottom line is, why do you need to know the exact delay? Typically you'd only need to know if you are using the FPGA as a timing generator, and in that case you would need to have a way of calibrating your output delay in order for it to be reliably repeatable.

Conflict of visa32.dll, since update to Labview 8.0 conflict with TEK software

We are Tektronix customers and with Labview
7.1/MAX everything was working ok with their software to communicate
with the oscilloscope from the PC. However, since upgrading to Labview
8.0 on system startup (XP) we get a message:
>
>"Tekvis.3
>
>The iInstalled visa32.dll is not a Tektronix
version of VISA. Either disable this program by removing it from the
startup directory of re-install TEKVISA."
>
>Obviously we would like to carry on using
Labview 8.0 and MAX, but also the Textronix software to grab
oscilloscope measurements without having to swap between these two file
versions. I re-installed Tektronix software but then MAX stopped working
from the NI suite, hence no devices could be seen. I presume that NI
will not be re-writing their new visa32.dll file to be backwards
compatible, will Tektronix be releasing a newer version of the software
that can use the new visa32.dll file? Or perhaps a visa32.dll file
compatible with MAX etc?
I have contacted Tektronix but I got this: "Unfortunately I only have LV 7.1 and, like you, it seems to work fine
for me. A collegue of mine tried this out with abview 8 and didn't seem
to have any problems. Have you contacted NI regarding why TekVisa works
with Labview 7.1 but not version 8?
>Hope you can help,
>
>Best regards,
>
>
>Daniel Hill

Hi DaniBCN
What versions of software are you using? LabVIEW 8 but what about NI-VISA? . You can download the lastest versions from ww.ni.com/downloads.
What scope are you using? What bus (GPIB, ENET, USB)? Here is a great resource to comunicate with tek scopes
http://digital.ni.com/public.nsf/websearch/202E14463D2D819F86256C39005D7828?OpenDocument
I know NI has a great relationship with tektronics (tek has a LV version inside the open scopes, NI has develop a specific version of SignalExpress for Tek scopes)
Hope it helps.
Javier Gutiérrez
NI Aplication Engineering

Need an Oscilloscope.vi with measurement capability

I'm running Labview 6.1 with a multifunction DAQ PCI-6035E board. I need an Oscilloscope.VI that will enable me to measure the time and voltage using cursors just as in an real oscilloscope. There's an example called "2 Channel Oscilloscope.vi" but it doesn't allow measurement. Any help would be highly appreciated. Thanks in advance!

Hi, to get cursors on the graph to read off the time and voltage values, u need to right click on your graph go to visble items and click on cursor legend. this then should pop up at bottom of graph, then with operate value hand cursor, click on the cursor legend it should open up and u should get cursors on your graph and then just read the values off in the boxes on the cursor legend.
Stuart

Fluorescence Time-delay Measurement using an Oscilloscope

Currently, I'm examining fluorescence through scanning through wavelengths on a monochrometer and averaging the signal on the oscilloscope, storing it all in an array and graphing in the end.
My goal is to time delay the value attributed to each wavelength in order to weed out rapidly decaying noise in my samples. The light source will be chopped, and a trigger line feeds into the oscilloscope.
Can this be done either:
through adjusting instrumental settings (I'm using a Tektronix 220, interfacing through GPIB)
or through manipulation of a triggered output waveform using integration with specified boundaries relative to the trigger time?

Hello Matt G:
I'm not sure if your instrument can handle this. Have you looked through the manual or tried contacting Tektronix about it?
Regards,
Roland A.
Applications Engineer
National Instruments
Check out VI Roadshow

I am trying to continuously switch images on the VI, but it freezes when I try to access an oscilloscope through its instrument driver.

I am drawing 2 different colored rectangles contiuously on the screen using a while loop. I try to get information from an oscilloscope while this is switching, but the loop stops while the instrument driver aquires the measurement. The oscilliscope value depends on the switching of the rectangles, so I need them to occur simultaneously.

First you should have the two operations in different loops so one doe snot stop and wait for the other.
This should get you closer to what you are asking if you are not doing this already.
Next, look at the code you are using to get at the scope. If it opens/reads/closes, you can sped things up by opening once, repeatedly reading and only close at the end.
If you have covered all of the above, then provide more info (i.e. post code) So we can be of further assistance.
FWI There was a version of VISA that code "Lock-up the CPU" when doing reads. Are using VISA and do you have the latest version?
Ben
Ben Rayner
I am currently active on.. MainStream Preppers
Rayner's Ridge is under construction

LabVIEW/SignalExpress: How can I automate measuring the time between two pulses?

Hi everyone, bit of a newbie here so please bear with me.
I'm a student at a university conducting a muon decay experiment with an oscilloscope connected to some photomultipliers. To summarize, if a muon enters the detector it will create a very small width pulse (a few ns). Within a period of 10µs it may decay, creating a second pulse. The oscilloscope triggers on the main pulse 5-15 times per second, and a decay event happens roughly 1-2 times per minute. I am trying to collect 10 hours of data (roughly 1500-2000 decay events) and measure the time it takes for each decay.
I've been able to set recording conditions in SignalExpress that starts recording on the first pulse and stops recording on the last. The Tektronix TDS 1012 oscilloscope however feeds 2500 points of data from this snapshot into a text file (for use in excel or other software). Even if I perfectly collected the data, I would have 100,000+ data points and it would be too much to handle. I don't know how (or if it's possible) to reduce the sample size.
To conclude, using Labview or SignalExpress, I would like to be able to have the software
1. Differentiate between the single pulse detections and double pulse decay events
2. Record only when two pulses appear on the oscilloscope
3. Measure the time between these two pulses and ONLY that to minimize the amount of data recorded.
Any help would be GREATLY appreciated, thanks!

Hi wdavis8,
I am not that familiar with Tektronix, but there should be a place in the dialog that you go through when you create the action step to acquire date to specify a sampling rate. That would allow you to reduce the number of data points you are seeing, but may reduce the quality of the data.
If it’s just a matter of that much data being hard to dig through when you have that many points, you could do some analysis on the data after the fact, and then create a new file with only the data you want to look at. For example, you could identify the peaks in the data, and based on the distance between them or the difference in magnitude, selectively write data to a new file.
Here is some information about peak detection in LabVIEW:
http://www.ni.com/white-paper/3770/en/
You could also do some downsampling on the data to get fewer data points:
https://decibel.ni.com/content/docs/DOC-23952
https://decibel.ni.com/content/docs/DOC-28976
Those are just a few quick ideas.
Kelsey J
Applications Engineer

Accessing cursor positions on Tek TDS3052 oscilloscope

Hello,
I'm trying to program a LabVIEW application using a Tektronix TDS3052 digital oscilloscope that I access via GPIB.
I have a got most of it running using the tkds30xx driver library that came with LabVIEW. However, I am missing one function: I need to query the user cursor positions set by the user on the scope. What I'm looking for is pretty much what the "TekTDS read cursors.vi" from the vi lib for the older Tek scopes does. I didn't find its equivalent in the TDS30xx lib, and unfortunately these routines cannot be intermixed.
Does someone know whether that function exists at all and, if yes, how to access it (where is it and what its name?)?
Thanks in advance for your help!
Best regards
K
ristian Laß

Hello,
For horizontal cursors try:
CURS:HBA?
The instrument should give a response in this format:
Horizontal Pos1;Pos2;Delta;Selected Cursor;Units
For Vertical try these:
CURS:VBA:HDELT?
Returns horizontal difference
CURS:VBA:HPOS? x = 1 or 2
Returns value of vertical bar ticks
CURS:VBA:UNITS?
Return measurement units
CURS:VBA:VDELTA?
Returns value difference between the bars ticks
If you are using the IVI driver, use the write to instrument and read from instrument VIs. If you are using the LabVIEW native one, VISA write and read should do the trick. Hope this helps.

Is there something wrong with a Oscar Gomez Fuentes 2Channel oscilloscope

Is there something wrong with a Oscar Gomez Fuentes 2Channel oscilloscope or are my devices configured wrong. I have DAQCard-6036E and SCC-2345 with SCC-Ft01 and SCC-A10 modules. The problem is that when I am measuring with A10 it effects to FT01's RMS and DC values. But when I am measuring with Ft01 everything is ok. So what's wrong?? I attached a picture of a front panel.
Attachments:
front_panel.JPG ‏132 KB

Neuvos,
Do any of the signals you are measuring have high output impedances (> 1 kOhm)? If so, you may be seeing cross-talk (or ghosting). Below, I have included links to a number of documents that discuss this issue and methods for eliminating it:
Data Acquisition: Troubleshooting Unexpected Voltages or Cross-talk in Analog Input Channels
Using a Unity Gain Buffer (Voltage Follower) with a DAQ Device
Is Your Data Inaccurate Because of Instr
umentation Amplifier Settling Time?
Good luck with your application.
Spencer S.

How do I measure pulse width in VeriStand 2010?

I'm using an NI PXI-6229 M Series DAQ.
I the channel set up in System Explorer and I have my input signal routed to the Gate of Counter 0. When I deploy and open the Workspace the measurement says 0 seconds although an oscilloscope shows a 7ms square wave at the terminal.
I think the problem may be that I don't have a timebase applied to the Source of Counter 0. How do I put an internal timebase on the Source? I would prefer to do so without changing any VIs and I definitely don't want to add an external frequency generator to my setup.

I think that the gate terminal cannot be used in that case. You might want to try to connect the external signal to the input terminal of the counter.
Once you have rewired the external connection you will notice, that NI VeriStand might not update the frequency that often. NI VeriStand doesn't measure the frequency/period by using a frequency task. We have used a simple edge counting task that takes the upper and lower limit of the frequency to determine the update rate of the frequency value. The more accuarate the settings are, the higher is the update rate. In order to get a feasible update rate, increment the lower limit to a value that will never be below the real minimum frequency of the external signal and set the upper value to the maximum expected frequency.
Thanks,
Tom
http://www.newgistics.com

DC oscilloscope measurement

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