selecting which channels to write a file

[AaScWi]

Hello All

I want know how I can easily select a set of channels to write to a file.

I am building a strain daq.  I have 24 channels.  I would like to group the channels according to where the guages are on the device.

Say the user puts channels 1-3 on the "Frame" and channels 4-7 on the "Motor". How can I write each grouping to an individual file?

Thanks in advance

Aaron

[MarkBlack]

AaScWi,

You can write individual channel to a file by splitting up the data from your DAQmx read VI using Split Signals.  This can be found in the Function Palette » Express » Signal Manipulation » Split Signals. 

This will split your data into each indivudual channel that you are reading.  If you want to write a group of channels together into a single file you can bundle just those channels back together with Merge Signals, which is found in the same palette

Let me know if this answers your questions. 

[AaScWi]

Thanks for the reply,

I already knew about the split and merge. I needed a way to id each channel because sometimes the channels being used will change.  The split and merge methods are to "hardwired" for my app.  Is there a way to use them dynamically? Ideally I would have a list of possible channels in the group and then  I would check to see which ones are present.  I have found on method that is working so far.  I assign names to the channels in the task and then use index waveform array by channel name.  I then merge those signals.  I haven't checked to see if it gives an error when a signal is not found though.

I've attached my vi its still a little crude

Aaron

[MarkBlack]

Try using the Select Signals express VI.  This may do exactly what you would like.  This should be in the same pallette as Merge and Split Signals. 

[MikeS81]

Hi AaScWi,

you can use a for loop and an index array block. See in the attached picture the red marked area.

Mike