labview error 2500

[SVJ]

Hello all,

I am trying to read a channel from a TDM file and send the data continuously over an analog port. This seems to function when I have only one analog output but when i try to use two channels, it shows an error 2500. This error is not part of the documentation and the exact message at my end is:

Invoke Node in _saveFloat64Channel.vi-

I am using Labview 8.0 with DAQ 8.3.1. The hardware in question is the NI USB 6251.

Please advise. 

Regards,

Shailesh.

[kikiduu]

Hi Shailesh,

It looks like a TDM error. Can you post the code so that we can understand the situation better?

[SVJ]

Hello Again,

here is the labview VI I am using. Once again, a description. i am reading one channel from a TDM file and starting a DAQ task to send the values to the AO of the NI USB 6251. i also want to send another set of values via a lookup table to the other AO.

Any help would be appreciated.

Regards,

[kikiduu]

Do you want to generate a waveform or just DC Value in both the AO channels?

[SVJ]

Waveforms in both. The array is just a dummy. It is to be replaced by another array containing actual values.

[kikiduu]

Things you can improve,

1.  Start the AI task probably just before you start the AO task, else if the read from file and genration takes time, you may get buffer overflow error.

2. Change the AO write to N Channel>>Multiple Samples>> 2D Double/ 1D Waveform depending on whether u are using Double or waveform data type.

3.  The error that you mentioned in the first post is most likely to come from the TDM write inside the while loop. There may be other errors, but you may be getting only the first one. So it will be a good idea to put a probe on all the three error wires inside the while loop and se if you are getting in in them or not.

4. Inside the while loop  after AI Read, the DBL conversion is not required. You can remove it.

5. I am not very sure what you are trying to do in the file read part?You can use array of DBL only if the number of elements that you read from the file and the number of elements from the lookup table are same. Else it is better to use waveform.

Can you try these things and let me know?