Urgent_Ground pins on usb 6008

[Ben]

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Ben wrote:

Is it just me or are itmes "3" and "4" flip-floped in figure 5 of the 6008's pdf?

It looks like the diff and single end labels are wrong.

Ben

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I agree.  Also, for the differential mode, the label should be AI0  (letters A and I, number 0) but they have it as A10  (letter A, numbers 1 and 0).

! See what happens when someone actually reads the manual.

Ben

[Miaa]

attached is the VI which i am using for my project. There are 5 channels each measuring the analog output of the sensor. in the labview program i will like to make sure :

1) should i use ANALOG > MULTIPLE CHANNEL>SINGLE SAMPLE>1D DBL or

                        ANALOG > MULTIPLE CHANNEL>SINGLE SAMPLE>1D waveform

or any other option.

will the value of the DATA elements (data(0) , data(1)....data(8) )  change with the above choices for AI (analog voltage input ) ??

2) in the cluster to element block it is giving me 9 elements ( data 0 , data 1, ....data 😎  where as i have only 6 channels. I was expecting 6 data elements ? How can we find out which element corresponds to which data ???

3) i have to perform calibration and it is important that i know which element corresponds to which data. can you suggest any other way of programming so that this is avoided.

4) after the calibration we are going to put all elements to data so that we can draw all the graphs on ONE plot

yes the input signals are in range of +-10V

[StevenD]

First off, this isn't really related to the orginal topic, you might wanna start a new thread.

Anyway......

Waveform data has exta info like the start time and time between samples, a array would just have the voltage read.

The array to cluster is giving you 9 elements becuase that is the default for it to give. Right click the function and there is an option to specify how many elements to create.

Also, you have 1 sample read in a for loop set to run 50000 times pretty much as fast as it can, updating all the charts and graph as it does so. You might be better off setting the DAQmx Read function to read N samples and wire 50000 to that instead. Would cut down quite a bit on overhead, however your charts would not update untill everything is done.




Message Edited by StevenD on 06-13-2008 03:54 PM

[StevenD]

Actually, now that I think about it you will probably run out of memory taking that many sample on 6 channels. Might want to look at the DAQmx timing function, then put your read in a while loop instead of a for loop. Then you can basically continously acquire, update your charts and graph every x points collected and stop reading when you stop the while loop.

[Dennis_Knutson]

You are only taking one sample so returning a 1D array might be a little more efficient. The values won't change either way. What might change is the channel order because you've given the operator the ability to select any channel and in any order. If you want to keep the same order, make the physical channel controls a block diagram constant.

The Array to Cluster function has no idea of how many elements might be in an array. You have to right click on it and select Cluster Size. There's no reason to use this function, though. Just use a single Index Array function or wire the array up to a for loop. Have your cal numbers in an array as well. You would then use another Index Array function to get the values for the numeric indicators. In other words, the coding is much more complex than it needs to be.

Message Edited by Dennis Knutson on 06-13-2008 03:18 PM