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Sequential Line Writing to DAQPad-6507

Here it is for LabVIEW 7.1 - let me know if you have any trouble opening it.

Regards,


Micaela N
National Instruments
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Message 11 of 23
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Hi McKala[DE],

This suits my needs perfectly, it is a very good program. I had recently finished a 1 to 16 program, but it was much more complicated than yours.

I have modified it slightly to include the following:

Ability to move from 96 to 1 (when starting line is greater than ending line) simply by adding in a case structure (TRUE if starting line is less than ending line, else FALSE). In the false case, I have replaced the +1 increment in the shift register with a -1 increment.

In addition, I have added in a final group write that will turn off the lines after the program is run (i.e. line 1 is written to for 5 seconds, then line 2 is written to for 5 seconds, and then everything is turned off).

Please let me know if you spot any errors, and thanks very much for your help. The file is attached below

Message Edited by Anthony_Wong on 06-05-2006 04:07 PM

Anthony Wong
University of Toronto
Chemistry Department
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Message 12 of 23
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Hi Anthony_Wong,

It looks pretty good to me, I did notice thought that the last write did not change any of the values of my line.  You might need to add an input to the patterned list, other I think you are good to go!

Regards,
Micaela N
National Instruments
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Message 13 of 23
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Hi McKala[DE],

I've managed to get it to write blank values to the lines at the very end now (just needed to add in a table with nulls).

However, when I was measuring the voltages with a voltmeter today, I noticed that when the starting line was greater than the ending line (i.e. moving from line 9 to line 8), I cannot measure any voltage. This problem does not occur when the starting line is less than the ending line.

When running the VI with the "Highlight Execution" button active, the values I note seem to be OK, so I do not see the reason for the problem.

Any help will be appreciated. Thanks again for your help.  

Message Edited by Anthony_Wong on 06-06-2006 10:27 AM

Anthony Wong
University of Toronto
Chemistry Department
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Message 14 of 23
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Just to clarify (since editing cannot be done) the above message.

The problem that occurs is that I cannot measure a voltage (both when starting line is less than OR greater than the ending line).

For example, if I set starting line as 10 and ending line as 9, and the VI is run, there is no voltage that can be read on line 10, but there is a voltage that can be read on line 9. If I set the starting line as line 9, and the ending line as line 10, there is a voltage that can be read on line 10, but not line 9.

However, this does not occur with line 2 to line 1 of the first port or line 1 to line 2 (of the first port).   


Anthony Wong
University of Toronto
Chemistry Department
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Message 15 of 23
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Are you probing the Replace Array Subset output?  In case you aren't, you can right-click on the output line and select probe, when you run highlight execution, it will show you the value on each of these lines.  I don't currently have a card with multiple ports.

Regards,
Micaela N
National Instruments
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Message 16 of 23
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Hi McKala[DE],

The program that you posted several days ago works fine, but I was testing it again today, and I seemed to have missed a problem.

When I select the start position as (say) 1, and the end position as 2, with a time interval of 5000 ms, I get line 0 turning on for 5 seconds, and then line 1 turning on for 5 seconds (so this is OK so far).

However, when I proceed to measure the voltages of lines 0 and 1 of the next port (in this case, the APB port), I read a voltage of 1.0 V; this is obviously not desired.

Is there any way to fix this?  

Your help is appreciated
Anthony Wong
University of Toronto
Chemistry Department
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Message 17 of 23
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Do you see the same behavior (ie - 1 V) if you use MAX to write to those lines directly?

Regards,
Micaela N
National Instruments
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Message 18 of 23
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Hi McKala[DE],

Unfortunately, the DAQPad-6507 (USB) that I am using right now only supports Traditional DAQ and not DAQmx, so I cannot test for that.  
Anthony Wong
University of Toronto
Chemistry Department
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Message 19 of 23
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Sorry about my above post, I misread the question (I didn't have my morning coffee Smiley Happy ).

McKala[DE], when I use MAX to write to the lines directly, I do not get the same behaviour (i.e. 1 V)

I only get this when I attempt to set the start position as 1 and the end position as 2 (lines 0 and 1 work as normal, but lines 0 and 1 on the next port (APB) are at 1 V). Interestingly enough, when I set the start position to 8 and the end position as 9 (i.e. line 0 and 1 of port APB), I do not get the same result (i.e. lines 0 and 1 of port APA are not 1 V).

Attached is the code that I am currently viewing
Anthony Wong
University of Toronto
Chemistry Department
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Message 20 of 23
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