my DAQ VI is not working after i edit it with formula

[danpullo]

Please i have problems with my Vi

The USB DAQ that am using can not be recognise directly.

i must use their VI and i can read the data.

I edited the VI and insert formula.but the coonection says its not possible.

please i attached the VI.

Thanks

[AdnanZ]

You need to desribe what exactly the error is and where you are getting it. Is it possible for you to post a screenshot? Also, what hardware are you working with and what exactly are you trying to do?

[danpullo]

Hi Adnan

 I am measuring the skin impedance with electrodes on the skin.

i measure the voltage acros the skin and i want to use the voltage to calculate the impedance and plots the results with time.

 The DAQ i am usings is from Quancom see attached pic name usbad8.

I wanted to directly use the DAQ assitance in the block diagram but it doesnt see the hardware.

but when i use their own VI (see pic1),i can get the data displayes on the channel 0. the block diagram for the VI is pic 2.

Now i needed to put in my formula in between the display and the Data aquisition block from the blovk disgram it does not work. please see pic 3 and also pic 4 which has the warning problems.

pic 5 is the graphic interface change that happen when i add the formula.

please tell me whats going on.

sorry i can attach only 3 docs

then i will attach the important once

thanks

am waiting

[AdnanZ]

That seems like a datatype mismatch. I am not sure if I understand from the screenshots what data it is, but if it is a cluster, you need to use the Unbundle node or use the Get Waveform Attributes if it's a waveform. Post the VI that you have shown in the screenshots and we should be able to help you. The VI attached above is not relevant in this case.

[Dennis_Knutson]

Don't post .doc files. They are proprietary file formats and they cannot be degugged. You didn't even include the image of the pertinent frame. Post the actual VI or just zip up the png files.

The error message is perfectly clear. Your source is a cluster of 8 elements. You cannot wire a cluster to the formula function. Since you did not include an image of how you are creating the cluster, it's impossible to say what you need to do. Maybe a simple undbundle?

p.s. Avoid the sequence structure. It's not required and just hides code. If you had not used it, it would clear what the whole program is doing.

[danpullo]

I send in my voltage fro functional generator.i use either sine or square waveform and my data is also a waveform. i am interested only on the amplitude of the waveform which is the voltage.

i hereby attached the VI

thanks amwaiting

[Dennis_Knutson]

You've got what appears to be data from 8 different channels in the cluster. Unbundle whatever channel you want and apply to the formula. If you want to apply the formula to all channels, it would probably be simpler to convert the cluster to an array and wire the array to the formula function inside a for loop.

p.s. Your data is NOT a waveform. Your data is a single point. The only way your program will display more than a single value in the chart is if you use the run continuous mode. This mode should not be used as a normal method to run your program.

[danpullo]

Thanks Dennis

   i try but it still didnt work.actually i taught you guys will know how they program the VI.i cant unbundle the channel.

i was thinking that the formula can take only 64bit while the VI is 32bit.maybe that the problem why it can not be wired.

please did you try what you told me?

i am really stalk with this.

i was planning to buy NI DAQ hardware but am not sure if i will have the same problem.but i have to make sure that  it will work.

please give me a helping hand with this  VI.

Thanks

[Dennis_Knutson · Accepted solution]

Why can't you unbundle the data? You just wire the Unbundle function to the same wire as the chart. As I said, this will give you a single value. Your VI is not capable of plotting more than a single value unless you are using the run continuous button and you should NOT be doing that. You have not posted your VI with the formula or with your attempted modifications.You are not giving all of the necessary information in order to fix your problem.

The idea about 64 bit and 32 bit is just silly.

[danpullo]

Thank alot

it helps.But i still have to edit the graph

so that it plot only few points.