06-06-2011 10:38 AM
Hi
I am able to acquire data from a potentiostat. However, I am only able to rip Current data and Voltage data off seperately (i.e: with two data dumps). Is there anyway to acquire both forms of data , and hold them within Labview in order to form an X-Y graph.
I can save both data sets as txt files. But am looking for something that would 'temp' store each data set and feed them both into an x-y graph.
Regards
B
Solved! Go to Solution.
06-06-2011 11:39 AM
Can you post your code so that we can see what you are doing so far?
06-06-2011 12:24 PM
Hi Tim
Sorry , I don't have any code at present . All that is there is a Quancom VI (.DLL call) which sends non NI-Commands in order to read a string from a certian GPIB listener e.t.c.
The data comes off as a text string and that's where I first get hold of it. It is easy to convert an element of the text string to a number and then deal with it as a number via the usual operations.
The potentiostat is very unusual EG&G 263A as it saves data as curves on the instrument and then switches to different curves as the amount of data points collected increases. I usually send a command to the instrument to release the data stored on on each 'curve' and that is why I get the 2 seperate streams. The two seperate streams are quite easy to deal with as you know exactly what you are dealing with when the instrument spits it out.
There is apparently a timing problem between this previously DOS controlled potentiostat and Windows XP/GPIB and so it can't plot the data points as well as take them at the same time without considerable difficulty.
So I call for for the first stream . Save it as a .txt file. Call for the second stream which plonks the data beneath the first stream. So far so good. I was hoping to store both streams in Labview (maybe in some type of an array or something??) and then split them off as X and Y inputs to the X-Y graph .
Sorry if this is vague .
Regards
B
06-06-2011 12:27 PM
Can you post the TXT file with both data sets as you would expect to get them from your device. Reading a TXt file into LabVIEW and plotting them should be a piece of cake.
06-06-2011 12:31 PM
Thanks Tim
I need to mention I have separated the two data 'streams' by a single number string which reads 261261
Will get to the office tomorrow morn and post it ..its 19:37 here now .
Kind regards
Barry
06-07-2011 01:23 AM
Hi Tim
Please find attached a txt file of the data . The first set of data (from the beginning) is seperated from the second set by the string 216216. The second set of data is also terminated by the string 216216. This is then followed by zero's
The aim is extract the first set of data and send it to the Y-input of a X-Y graph and extract the second set and send it to the X-Input of the X-Y graph , using this string '216216' as a help of sorts. The two data streams can also be divided using their length , as the 'x-data' will have the same length as the 'y-data'
Thanks very much for your help in this .
Regards
B
06-07-2011 01:53 AM - edited 06-07-2011 01:59 AM
Hi,
Take a look at the attached vi. It does what you wanted. It extracts the first and second set of values from the txt file on the basis of the value 216216 and passes the first set of values to the Y and Second set of values to the X of an XY Graph.
Regards,
Nitzz
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06-07-2011 02:12 AM
Geez ..thanks Tim
That was super speedy and exactly what I was looking for !!
Thanks again fo all your help. Excellent stuff
Keep well
B