AO output/start digital edge

AO output中，我想用DAQmx write来写入电压信息到buffer，然后用DAQ start task开始产生电压。我的程序中用start digital edge指定每个pulse的falling edge来开始产生电压。我的问题是电压是不是只有在pulse的low edge电压才能产生，而当下一个rising edge是，产生就会停止呢？还是说start digital edge只决定第一次电压写入的时机？望高人指点！

可以贴程序框图看看么？
Thomas | Xi'an China
LabVIEW 7.1 | LabVIEW 2011
DAQmx | CompactRIO

Similar Messages

Why does Start Digital Edge in Start Trigger.vi do a kind of timeout?

Hi I am doing a manual trigger on my hardwareboard by inserting a 5 volt source into the selected triggerchannel a couple of seconds after I push the start button.
The generation never starts. But if I put the trigger signalchannel equal to the external sampling clock the appended vi work.
Example I use PFI7 as trigger source which is also the source of the sampling clock.
Could somebody explain?
Kindest regards,
Lasse
Solved!
Go to Solution.
Attachments:
Cont Gen Voltage Wfm-Ext Clk-Dig StartA.vi ‏36 KB

One cannot just insert a wire with a 5 V potential to PFI6 for instance if PFI6 is used as a trigger for "Start Digital Edge" daqmx -vi. The pin is floating and just inserting 5V does not guarantee a low to high edge.
If I use a potentiometer to pull the channel low first, and then increse the voltage, the trigging happens.

DAQmx trigger: start digital edge

Buongiorno a tutti.
Mi trovo a lavorare su un VI creato in precedenza da altri colleghi, quindi sto cercando di migliorarne alcuni aspetti.
Lo strumento si occupa dell'acquisizione di segnali di temperatura e pressione da svariati sensori. I colleghi hanno inserito una fonte di trigger esterna attraverso un generatore di funzione (tektronix AFG3021C). In allegato una immagine della sequenza precente al ciclo while di acquisizione ed elaborazione dei segnali.
La mia domanda è questa: "è possibile ovviare all'utilizzo del generatore esterno di funzione?"
Grazie
Luca
Allegati:
acquisizione.jpg ‏155 KB

Ciao Luca,
strano che non ti compare niente, prova a cancellare l'intera funzione e richerla, dovrebbe almeno apparirti i vari PFI della scheda DAQ che hai collegato al PC... Sei sicuro di aver collegato qualcosa?
In ogni caso ***** vuoi come trigger una forma d'onda generate internamente, quello è un trigger software, prova a guardare questo esempo:
https://decibel.ni.com/content/docs/DOC-35941
Buon lavoro e buona giornata,
Valerio

Getting error -200452 using DAQmx Base Trigger (Digital Edge).

I'm trying to set up AI and counter output, and I'm using digital output as trigger for to start AI and counter at the same time. I get error 200452 "Specified property is not supported by the devise..." not consistently, but around 5 runs out of 100. Below the error description, the error box shows "This error code is undefined. No one has provided a description for this code..." If I "Retain Wire Values" in Block Diagram, the error first appears after 'Start Digital Edge' block in top counter output line.
Using LabView 8.5 on MAC OS X and DAQmxBase 3.2
The MAC I have is not Intel base, so I can't upgrade LabView and DAQmxBase to latest version
Note: The file contains just a small portion of the program, but the rest of the program does not have any other DAQmxBase blocks accessing the channels used here in code attached.
Attachments:
Combined V 1.5.41_sm.vi ‏98 KB

Hi Azotov,
It looks like the DAQmx Base driver readme includes Mac OS X support for LabVIEW 8.5. Could you specify what hardware you are using?
I found one KnowledgeBase specifying that error code occurs when you try to use certain properties with certain devices. Of course, this would most likely occur every time you run the task, not 5% of the time.
Since I'm running Windows, it's a little difficult to see if you have DAQmx Base "Reset Device" functionality with that version of the driver. You might check if you can run that functionality before using your device, though.
National Instruments

USB scope triggering off wrong digital edge

All,
I have setup my USB scope card (5133) to trigger of a positive digital edge on the PFI input. This then captures rising analgue connected to the two channels. This normally works fine, but sometimes the scope will start to trigger off a negative edge! (digital input signal is a digital pulse). To get the scope to work correctly again I have to set the scope to trigger off an analogue edge on ch0/1, then after runing the vi once return to the digtal edge trigger on PFI1. I have attached an image of the setup of my scope.
Attachments:
trigger.jpg ‏290 KB

Hello,
I don't immediatly see anything wrong with the screenshot of your VI. I have a few questions about your setup that will help narrow this down.
1) What are you using as the source of your digital trigger on PFI 1? Have you verified that this digital signal meets the VIH and VIL levels specified in the 5133 spec sheet? http://digital.ni.com/manuals.nsf/websearch/8D323D9E4F4B39288625737C0071E462 (Page 7) Also make sure you are not exceeding -0.5V or +3.5V and that your pulse width is greater than 20 ns. The easiest way to verify this would be to run the configured acquisition example VI with your digital trigger signal running into one of the analog input channels.
2) How are you connecting your signals to your board? Are you using BNC cables or probes?
3) I am assuming that the signals you are digitizing on ch 0 and ch 1 are different than the signal you are feeding into PFI 1. If you have a BNC splitter handy try splitting the signal you are feeding into PFI 1 so that it also runs into one of the input channels. Leave the other analog input channel unconnected. Then run your VI again and see if you see the same phenomena where it looks like the scope is triggering on the falling edge of PFI 1. If the scope is triggering on the falling edge you should see the falling edge waveform captured on the analog channel. This will help us determine if the scope is triggering on the wrong edge or if your input signal and digital rising edge are not always correlated. If you are using probes instead of BNC cables you can do the same test, just connect both probes to the same signal.
Regards,
Matt

How to input/output a digital signal and acquire an analog signal at the same time?

Dasylab, version: 8.0.04
Acquirement Card: PCI1002L
When I use DasyLab to acquire the analog signals is no problem without digital inputs and outputs,
and when I use DasyLab to input or output a digital signal is no problem also, but when I do that at the
same time, DasyLab tell me the rate is too high and stop.
so, I searched the manual book1 (user guide) for that, it showed me :
To internally equalize measurement time and system time in the analog input, digital input and counter
hardware modules, use the following settings:
   Synchronization: PC Clock
   Sampling rate: <= 5Hz
   Block size: =1
the problem is, if I set the Sampling rate to 5Hz, the speed of the acquirement datas is not enough for my
application.
so, how to improve it? who can give me a example programm for me. thanks!
by the way, I come from China, my English isn't good, I'm sorry.
Allen, China.

Hi,
Have things changed over the years?
I need to syncronise a digital output (Modul NI9474) and an analoge input (AI-Modul NI9203) module. I need to measure time intervals from a flank in signal A to a flank in signal B. I would like accuracies of the order of 1 ms. Currently, the signals are not synchronised, with errors of the order of 2 times the block length (block size x sample rate), sometimes much higher. The best I got so far was a block size of around 20 with a sample rate of 1 kHz.
If I use the master and slave settings on the RTSL settings, my program doesn't run properly.
If I use digital signals for input and output, I can syncronise them with RTSL settings and everything is good, but I can't always do that.
Also, if I do anything in the GUI (such as scrollowing something or going to another window), my output gets screwed up properly.
1. What can be done to synchronise AI with DO?
2. Is there something that can be done to avoid messing up the output when something happens in the user interface? (I know that I am messing up the outputs as they make some valves switch and that is loud).
Thanks in advance!

How to output the digital clock and synchronization signal from the NI USB-6211

Hello,
I need to connect the NI USB-6211 to control a digital to analog convertor chip (AD5541). However, this chip requires three input signals :1) Clock input, 2) Logic input or a synchronization signal and 3) Signal Serial Data input (CS, SCLK, DIN).
how to output the digital clock and the synchronization signal from the NI USB-6211?

Hi SaberSaber,
You should be able to use the counters to generate a pulse train that could be used for clock and synch purposes.
Hope this helps. Let us know if you have more questions.
Dave C.
Applications Engineer
National Instruments

How do I output three digital waveforms at once?

I posted this in Digital I/O, but now I think it's actually more appropriate here because it's not a hardware question. I need to output three digital waveforms at a relatively low frequency, 71.9 Hz. I have a PCI DAQ card, the 6024E and am using the NI-DAQmx functions to try to do this. My program basically generates the square wave that I want, and converts it into a digital wave. I do this 3 times for the three separate waves, and then I combine them into an array and send them to my DAQ functions, which are in a while loop so I can get continuous output. My problem is that the waveform that the DAQ is actually outputting is not what I want. It's outputting a wave that has the same duty cycle (approximately) but the frequency is over 2 kilohertz. It's not like this all the time; after it outputs about 7 cycles of this wave, it goes to logic low for a long time, and then repeats itself. When I probe the digital waveform right before it goes into the DAQ functions, it's running correctly at 71.9 Hertz. Am I doing anything wrong with the DAQ functions or the sampling information? Thanks in advance.
-- Josh Matloff

Hello Josh,
I'm pretty sure that the reason that your digital waveforms are not being produced at the correct frequency is because your digital output is not associated with any sort of timing. Unfortunately, with an E series board you can only do software timed digital operations. This means that the frequency at which the values on your digital lines will be updated depends on how fast/often your computer executes the DAQmx Write that is inside of your while loop. If you have an M series board, you can actually correlate the DIO operations with another subsytems clock (AI/AO sample clock, etc.) which means that you can acheive hardware-timed DIO. In the event that you do not have access to an M series board, I think that AnalogKid2DigitalMan was spot on that you would want to use counters to generate pulse trains (that is if your digital waveforms have a constant duty cycle and period). Depending on what the DAQ board is outputting to, you might also want to consider using the Analog Output channels to generate your digital waveform. As long as you continue to use the digital lines on the 6024E, there is not really a way to guarantee the timing of when the digital lines will be updated. You might be able to get close, but you will probably see some "hiccups", especially if your computer needs to service interrupts or give processing time to another application. And lastly, heed geckoee's advice and don't forget to properly close out your tasks! Putting in some error handling may also help in the debugging process.
Take care,
E.Lee
Eric
DE For Life!

ITunes rented movie not outputting Dolby Digital 5.1 audio

The problem with the downloaded movie (Real Steel HD) is
that the Dolby Digital 5.1 (English) audio is not being putput. The movie is only playing back in
"stereo" mode. When playing back on iTunes there are four audio tracks
to choose from:
1. English 1 (This plays stereo)
2. English 2 (NO SOUND) - I believe this should be the Dolby Digital track
3. French (This plays stereo)
4. Spanish (This plays stereo)
Neither of the two English tracks is outputting Dolby Digital 5.1 audio.
I have confirmed that my PC is capable of up to 7.1 surround sound and
my A/V receiver is capable of even more. I have updated both the ATI
Radeon 4500 driver and the Realtek drivers. I have tested and
confirmed that my PC is capable of outputting sound to all 5 of my
speakers and my subwoofer, HOWEVER when playing back the rented movie
in iTunes the maximum audio is stereo. I have the latest version of
iTunes installed, so that shouldn't be the problem.
I have also purchased another movie advertised as Dolby Digital 5.1
audio (The Bourne Supremecy HD) but I am afraid to begin my 24-hour
viewing period because of these audio problems being unresolved.
My question is: Are there known issues of movies purchased on iTunes
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tracks? If so, is there a fix for this via an iTunes settings change
or a Windows update patch?
From the four audio tracks that I listed above, I believe track 2 is
the Dolby Digital track, yet there is NO SOUND when that track is
selected.
Please help, as this is pretty frustrating when your movie night is ruined for the family especially after you've paid for and waited for the movie to download.

I managed to get my DD tracks working.
First had to update itunes to the latest version (10.7.0.21) to get rid of the out of sync sound problem
Then updated the realtek driver. There was an update directly in the realtek website (mine is the HD Audio): http://www.realtek.com.tw/downloads/downloadsView.aspx?Langid=1&PNid=14&PFid=24& Level=4&Conn=3&DownTypeID=3&GetDown=false
After all that. I tunes wasn't allowing anymore to select the Doubly Digital 5.1 tracks (an improvement).
Then went to the windows properties for the realtek optical output and checked both options to allow application exclusive access and to have priority (http://dailykermit.wordpress.com/2009/09/11/windows-7-exclusive-device-control/)
After all this, I was able to enjoy my rental

How to set the AppleTV to output PCM DIGITAL via toslink

how do you set the AppleTV to output PCM DIGITAL via toslink - my amp can only recieve PCM audio via toslink cable

I am having the same problem. I bought an optical-analog convertor from Amazon (SANOXY) and had Onkyo try to help me set it up. No luck. I am going to try a Monoprice version. I was able to output audio through my DirectTV box to the Zone 2 speakers, so that isn't the problem. I was able to hear the music from my iMac through the AppleTV/Onkyo receiver on the 5.1 side but was unable to output it through Zone 2 to the speakers.
Very frustrating!!!!

Multiple Channels with Single Digital Edge Trigger

I have a simple vi where two analog channels are read in and recorded simultaneously to a lvm file and plotted on a waveform graph. I need a digital edge to post trigger the data acquisition for both channels.
I can get this vi to work with one analog channel and the digital edge trigger just fine.
When I remove the digital edge trigger, I can get the vi to work with both analog channels. Both signals plot on a waveform graph, and record nicely in the lvm file.
The issue is how I am setting up the digital trigger (see attached). The program is never entering the while loop. Where am I going wrong?
Chassis:cDAQ-9172
Analog Card:NI 9205 (Trigger Source PFI0)
LabView: 8.6
OS: Windows XP
Solved!
Go to Solution.
Attachments:
Analog Input with Digital Edge Trigger.vi ‏52 KB

Gardma,
I am going to take a quick guess (I'm lazy and haven't actually tested the code ), but, since it works without the trigger and given that you have it so that the read never times out (i.e. = -1), there is something going on such that the trigger is never generated on the source pin. Just a thought.
Cheers, Matt
Matt Richardson
Certified LabVIEW Developer
MSR Consulting, LLC

When I unplug Apple headphones from my MacBook Pro sond from internal speakers not work, and system soud preferences displayed: Output: optical digital out port only

When I unplug Apple headphones from my MacBook Pro sond from internal speakers not work, and system soud preferences displayed: Output: optical digital out port only

If you see a red light in the audio output port, then the internal switch is stuck. Insert the earphone plug a few times and see if you can trip the switch. If that fails, insert a cocktail stirrer and the like and jiggle it around inside. If that fails, take it to an Apple store and have the technicians at the genius bar do it for you.
Ciao.

Why did Start Analog Edge stop working?

I have been using the Start Analog Edge DAQmx function to initiate my data read (similar to the Multi-Devices Synch-Analog Input-Finite Acq-Analog Start.vi example). It has worked fine for several days, but recently stopped working. I can see the signal at the hardware test panel, I can see the trigger signal on the waveform if I route around the start trigger function. I cannot actually get the function to recognize the start trigger.
Not sure what other sort of debugging I can do. Hopefully, someone has encountered this before and can clue me in to what I am missing.
=Jason Hill
New Product Engineer
Groth Corp.

Hi,
I have a couple questions for you to help narrow down the issue:
1) What device are you using?
2) What driver are you using?
3) What has changed in the setup (hardware and software) from when it was working to when it stopped working?
4) You are using a multiple device VI. Is that because you have multiple devices you are trying to trigger. Please explain in more detail what you are trying to do and how you are trying to do it.
You could use the ContACq&Graph Voltage-Int Clk-Analog Start.vi to do the same thing with just one board. This may be better suited for your needs. This example can be found in the LabVIEW example finder.
I hope this helps. Have a Great Day!
George

ADAM Service cannot be started on edge server - cannot uninstall the role and ...

Hi,
after a storage failure, some files seemed to be damaged on exchange 2010 edge server
it said it could not connect to DC and i realized that is because ADAM service stopped
I tried to start it but encountered a weird error (0xc000000) some thing like that
so i found that adamntds.dit is corrupted
I issued this :
C:\Program Files\Microsoft\Exchange Server\V14\TransportRoles\data\Adam>eseutil /p adamntds.dit
it said integrity check ok but after that again ADAM does not start and says
this service started and the stopped ... (the famous message we all know)
1- now is there any way to fix it?
2- is it reasonable to use the other edge server database file on this one (we have two edge servers) or it is non-sense
3- according to this
http://social.technet.microsoft.com/Forums/exchange/en-US/93ed667c-5a37-404c-9471-d2525621a371/adam-service-wont-start-on-edge-transport?forum=exchange2010
and the advice of Ed my dear friend on Technet, itmay be better to reinstall it
but it does not even let me to uninstall it and says :
Summary: 2 item(s). 1 succeeded, 1 failed.
Elapsed time: 00:02:58
Configuring Prerequisites
Completed
Elapsed Time: 00:00:41
Edge Transport Role Prerequisites
Failed
Error:
The Active Directory Application Mode (ADAM) service must be started before Setup can continue.
Click here for help... http://technet.microsoft.com/en-US/library/ms.exch.err.default(EXCHG.141).aspx?v=14.3.123.3&e=ms.exch.err.Ex28883C&l=0&cl=cp
so somebody please tell MS guys if i could start it why should i uninstall it :P
and i do not want to use manual methods to do the removal if possible
and much better if i can fix it without even uninstall exchange
thanks to all

Hi,
I would like to verify if you have a backup of ADAM directory.
If yes, please put it on the server and try to start the ADAM service.
If no, I recommend you recover the ADAM directory as the following steps:
1. Use esentutl /g.
2. If Integrity check is successful, use this cmdlet: esentutl /d.
3. Use esentutl /r edb.
4. If above steps fail, use esentutl /p adamntds.dit. Then delete all files in the directory except for the adamntds.dit. (Note: Before you delete the files, please take a backup for them.)
5. Try starting ADAM service.
Hope it helps.
If there are any problems, please feel free to let me know.
Best regards,
Amy
Amy Wang
TechNet Community Support

Can airport express output a digital signal to feed a separate audio DAC?

Can airport express output a digital signal to feed a separate audio DAC?

Yes. To access the digital output from the AirPort Express Base Station's (AX) audio port, you will need to connect a mini-TOSlink digital optical cable.

AO output/start digital edge

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