myDAQ error 200463

[Omershah]

Hello

i am using myDAQ to communicate bwtween digital lines.

I am using lines 0,1,2,3 as digital inputs and lines 4,5,6,7 as digital output. I am not using express VIs.

Attached VI has error 200463. I tried all the options in the DAQmx VI but was unable to communicate.

Please HELP...

Regards

Omer

[crossrulz]

Since you are writing to multple lines, you need to use the Multiple Channels->Single Sample version of the DAQmx Write and DAQmx Read.

[Omershah]

Hello crooss rulz,

Thanks for your suggestion. I changed it but its giving the same error.I attached the new VI please check and help.

Regards

Omer

[Bob_Schor]

Have you tried using MAX with your myDAQ?  Or have you put your VI inside a LabVIEW Project and tried defining the Task as a New Task in the Project?  If you'd done either, you would probably have noticed that when you want to configure multiple channels, you select them all as a group, e.g. myDAQ1/port0/line0..line3 (I'm not sure of the syntax when I just type it -- in MAX or Project Explorer, I just click on the lines I want and use the Task Constant that this generates).  You want to be defining a single Task with multiple Channels ...

Bob Schor

P.S. -- always "play" with your Device using MAX first, to learn how to do such things as specify multiple channels all at once.

P.P.S. -- did you look up your Error Code using LabVIEW Help?  There is no Error 200463.  However, Error -200463 says:

Specified read or write operation failed, because the number of lines in the data for a channel does not match the number of lines in the channel.

If you are using the Digital Waveform datatype, make sure the number of lines in the digital waveform matches the number of lines in the channel. If you are using boolean data, make sure the array dimension for lines in the data matches the number of lines in the channel.

In other words, you asked it to read N channels but the Task only specified 1 channel.  You need to make the task specify N channels -- see how MAX or the Project Explorer does this.

[Omershah]

I tries with DAQ assistant and ELVISMX VIs and it is working properly but the requirement of my project is do it with DQmx read and write module.

Also i with different options but it does not work. If you @ Bob_Schor can make the required changes in attached VI it would be really helpful.

Regards

Omer

[Bob_Schor]

If you @omershah could follow my suggestions and make a Task, either in MAX or in LabVIEW Project, that bundles the channels together so that the Task is, indeed, a Task involving N (4, in this case) Channels, I'd be happy to show you how to do this.  Except I wouldn't need to, because you'd probably figure it out yourself (your code is basically correct except you have the wrong constant wired in to Create Channel, which you might not even need to use ...).

Bob Schor

[Omershah]

@Bob_Schor. Please give me your suggestions and i will work on it.

Also by MAX you mean DAQ assistant VI or?

[Bob_Schor]

Omershah,

     Do you have two different threads going on the same problem?  I just wrote a long answer to another post of yours -- is this the same issue?  It is confusing to us to have to juggle two threads for one problem.

     You have now posted a different myDAQ error, and again there is no such error.  There is, however, an error -200463 (you do understand the difference between positive and negative numbers, don't you?  The sign is important).  The explanation you were provided when you got Error -200463 was "Specified read or write operation failed, because the number of lines in the data for a channel does not match the number of lines in the channel."  Your VI seems to be defining one-channel Tasks, but you do an N-channel read, thus generating the Error.

     MAX refers to NI's Measurement and Automation eXplorer (M A X), whose icon on your desktop should look like this:

     My suggestions on your other post apply to this one, as well.

Bob Schor