zorro

QUOTE (Tom Bress @ Aug 15 2008, 11:26 AM) Thank you Tom. There is another hardware which receives the analog triggering from my LabVIEW program. And this hardware has a matched software that can display the signal the hardware receives. So this is how I get that graph. I don't know if I plot my analog out channel directly since I know nothing about that hardware and its software. Now I understand a little bit about what you mean in your second paragraph. Thank you.

QUOTE (jdunham @ Aug 14 2008, 07:56 PM) Hi, jdunham, Thank you for your help. The analog triggering is not in a subvi in my main program. I can't post my main program here. It is a huge one. But I write a vi which has the same structure and setting with the triggering part in my main program. Let's call this vi as "TestTriggering". A new problem with this TestTriggering.vi is that it always generate a strong noise, which doesn't show in my main program. I hope you can help me with this problem and the random drop. Thank you so much.

I am using NICard E3016 to generate two analog outputs. There are two channel on the NICard. My design is to generate 0V initially and after 5 seconds, the voltage changes to 5V so that another softerware starts to save data. Everything is fine except there are random drops in the analog output channels. You can see them in the picture. Could anyone tell me the reason for this ridiculous random drops? Thank you very much.

QUOTE (Anders Björk @ Aug 8 2008, 03:02 AM) Thank you. But I still can not get the voltage at the output pins. I think there might be 2 possible reason: 1. I didn't get the right data array which is the input of the DAQmx Write.VI. According to the help document, the data terminal of the DAQmx Write.VI should be "Each element in the first dimension of the array corresponds to a channel in the task. Each element in the second dimension of the array corresponds to a sample to write to each channel." So hpw to get the right data array from the 3 lines in the attached picture? 2. I didn't use the right DAQmx VI. Besides create channel,vi, start.vi, write.vi, stop.vi and clear.vi, the Timing.VI is also neccisssary for the digital output generation. I used to try to add the timing.vi between the create.vi and the start.vi, but when I stop the main program VI, there is an error showing on the screen. I put the error in the attachment. These two reason might cause me stuck. But I have no idea how to fix them. Any help is aapreciated. Thank you very much.

"Each element in the first dimension of the array corresponds to a channel in the task. Each element in the second dimension of the array corresponds to a sample to write to each channel." This sentence is from the help document of LabVIEW 8.2 for "DAQmx Write.VI(Digital Output)." My question is that for a 2D array, is the first dimension of the array the colum or the row? Thanks a lot.

QUOTE (mross @ Aug 5 2008, 05:17 PM) Hi, Mike, "Is the receiving hardware the same E Series DAQ card?" I have no idea of the receiving hardware now. It is a non-NI equipment. The technical person in that company told me it was compatible with 6036E. But I haven't seen it. "It sounds like the generated signal is only a trigger signal. Is this correct? Or is the signal something more complcated." the generated signal is only a trigger signal. And the 8 digital outputs have to be used for other functions. Thank you very much for your help. Luckly I get the analog output valtage and I can see it from voltmeter. I can see the change. But I don;t know whether it works well with the new equipment, which I haven;t seen.

Thank you for those nice and experienced people who helped me here. I am using LabVIEW8.2 and I want to use NI-DAQCard6036E to generate 3 channels digital outputs, which are in the time series. There are 8 digital channels on the NI-DAQCard6036E. What I want is: The numbers in Channel are 0 and 2(At first it is 0, after 2s, it becomes 2); The numbers in Channel2 are 0 and 1(At beginning it is 0, after 3s, it becomes 1) and the numbers in Channel3 are 1 and 0(Channel2 is reversed to Channel3) Question1: How to choose physical channel? What do port and line mean? which one should I choose in the attached picture2? Question2: The three lines in the attached picture1 are carrying the digital numbers. Can I do in this way? Question3: In the attached picture1I am using create channel.vi start.vi, write.vi, stop.vi and clear.vi to generate the digital output. Is it right? Do I need timing.vi? I tried to use timing.vi, but it always gives error. Then I remove timing.vi, error doesn't show. Question4: How to build a 2D array to connect with the data terminal of write.vi? Is my method right ot not? I hope someone can help me with these problem. Thanks a lot.

Dear all, I want to make a VI that can collect data from analog input channels and generate a step function voltage to an analog output channel at the same time. I am using NIDAQCard 6036E and LabVIEW 8.2 to do this. What I have already done is the data collecting part, which works well. The I want to add the output part to the program, but I fail. The voltage I want to generate to the output channel is a step function. For example, at the first 10s, the voltage is 1V and after 10s it becomes 5V. What I have done with this part is that I use a physical channel and create a virtual channel.vi (AO), start.vi and write.vi and clear.vi. The write.vi is in the while loop and an array (The array includes the voltage function) is connected with the data terminal. But when I run the program, I cann't measure any voltage at the output pin of NIDAQCard. The voltage is always 0. When I stop the program, it will show an error, which I don't know what it does means. How to fix this problem and make the program work? Thanks a lot. http://www.ni.com/pdf/manuals/370721c.pdf http://www.ni.com/pdf/products/us/4daqsc20...229_238-243.pdf

QUOTE (mross @ Aug 4 2008, 01:33 PM) Dear Mike, The Output Range of the Analog Output is from _10 to 10V. Unfortunely, I have little knowledge about EE and can not totally understand what the specification says. http://www.ni.com/pdf/manuals/370721c.pdf http://www.ni.com/pdf/products/us/4daqsc20...229_238-243.pdf

Dear all, I want to generate a voltage and transfer it to an analog output channel, which is used to trigger another program. Can LabVIEW achieve this goal? Which function should I use? Can I use DAQmx physical channels? It seems that DAQmx physical channels only has input channel. I hope someone can provide some help and any help is appreciated. Thanks at advanced.

QUOTE (mross @ Jul 31 2008, 04:54 PM) Thank you very much. It is really helpful. Another question is what happens if Iwire the right side SR of the upper node of Build Array function?

I want to generate an array by a While loop with an indexing tunnel. But my VI doesn't work. The wire inside the loop can transfer data but the one outside the loop doesn't and I can't get an array. Could anyone explain the reason of it? How does a loop(While and For) work with an array in LabVIEW? And how to change my VI to fix this problem? Thanks as advanced.

QUOTE (Ton @ Jul 31 2008, 03:43 PM) Thank you so much. I am going to try it.

QUOTE (zorro @ Jul 31 2008, 01:37 PM) Thank you for you guys help. I made a new one and it seems to work. But a new problem is that I can't get an array which includes time and Voltage data. The output of this VI should be an array, which includes time and voltage data. My new VI is attached. Could you help me with the array stuff? Thanks a lot.

QUOTE (JDave @ Jul 31 2008, 01:28 PM) Thank you very much. I want to use this VI to trigger another program. The voltage value is used to be an analog output. When it is Time1, the voltage number becomes Voltage1, which triggers another program to save data. Where to find "ms timer"? I made a VI and it didn't work. I will attach it later. Could you help me to check it? Thank you so much. My VI is attached now.