topic Re: using scan from string in LabVIEW

using scan from string

raghu670 — Wed, 25 Aug 2010 17:48:03 GMT

I am reading a string from an instrument in the format hr:min:sec, 0.000, 0.000, 0.000,0.000

I need to separate each part and add it to an excel file. I have triend scan from string and

string subset. I am unable to use scan from string as the first output is in different format than the others.

I cannot use string subset as the value changes to a negitive value sometimes which makes it difficult to get the right string lenght.

Can someone help me in figuring out the best way to split the string and add to an excel file

Thank you in advance

Raghu

Re: using scan from string

aeastet — Wed, 25 Aug 2010 17:50:27 GMT

Do you have an actual string that you can attach?

Re: using scan from string

raghu670 — Wed, 25 Aug 2010 17:52:00 GMT

I am reading it from Visa read buffer

Re: using scan from string

aeastet — Wed, 25 Aug 2010 17:53:21 GMT

Can you read one into a string and save it ina control or indicator, Text file etc... ?

Re: using scan from string

raghu670 — Wed, 25 Aug 2010 18:14:30 GMT

Yes. I can read and save as an indicator

Re: using scan from string

aeastet — Wed, 25 Aug 2010 18:17:48 GMT

Save it as an indicator with the default value and post it here and I will see what I can do for you.

Re: using scan from string

smercurio_fc — Wed, 25 Aug 2010 18:18:02 GMT

Well, then why don't you do so?

Or, run the VI and get a screenshot of the result. Post it. Note: DO NOT UPLOAD BITMAPS, AND DO NOT RENAME BITMAPS TO TRY TO GET AROUND THE BAN ON BITMAPS.

Re: using scan from string

raghu670 — Wed, 25 Aug 2010 18:41:23 GMT

I could not paste the screen shot.

Here is the indicator value

12:02:07, 0.002, -.---, -.---, -.---,

in the mean while i am trying to upload screen shot.

Thank you

Re: using scan from string

Darin.K — Wed, 25 Aug 2010 18:35:44 GMT

As much fun as it is to parse strings, Excel is perfectly happy reading comma separated values, and simply appending those strings to a text file should work. Name it 'whatever.csv' and you should be good to go.

Re: using scan from string

raghu670 — Wed, 25 Aug 2010 20:00:57 GMT

Here is the screen shot after I ran the vi. Along with copying the data to an excel sheet I need the individual data to use in my program later.That is the reason I wanted to parse the string.

Thanks,

Raghu

Re: using scan from string

smercurio_fc — Wed, 25 Aug 2010 21:23:54 GMT

As Darin noted, if you just write the string that you read directly to the file then you should be able to open it in Excel by simply specifying commas as the delimiter. Instead of using Write to Spreadsheet File just use Write Text File.

Re: using scan from string

Darin.K — Wed, 25 Aug 2010 21:27:13 GMT

What do you intend to do with the -.----- values? You could leave them alone (they would have to be strings), you could convert to DBL and they would default to 0.0, or you could do some checking and change them to NaN for example.

How would you like the time formatted for your program? Timestamp (you would need the date), seconds since midnight (DBL) or individual values for Hour, Minutes and Seconds?

As for writing to an "Excel" File, I would still recommend writing the string to the file directly.

Re: using scan from string

raghu670 — Thu, 26 Aug 2010 13:13:15 GMT

the -.--- valuse are pressure readings. I need to get the values compare to a setpoint and then control a pump. I am trying to use scan from string and get the values. Also am using the format as %[%f:%f:%f],%f,%f,%f,%f. After I run the vi it returns me an error saying

Error 85 occurred at Scan From String (arg 1) in pressure sensor.vi

Possible reason(s):

LabVIEW: Scan failed. The input string does not contain data in the expected format.

Also string subset is not working as the value is -ve sometimes and its changing the count. So it is returning , to the excel sheet.

As far as the timestamp, we have decided it is not important to write it to an excel sheet but would be better if we could.

Thanks,

Raghu

Re: using scan from string

DFGray — Thu, 26 Aug 2010 13:32:12 GMT

If you really want to parse this and not use Darin's suggestion, the easiest way I know to do this is a two stage process:

Use Spreadsheet String to Array with the delimiter set to comma and the array type to string array to separate the individual elements.
Use Index Array to get the individual elements and parse them as necessary.

You will then need to convert them back into a string and back into a tab or comma separated text file for Excel to read. Alternately, you can use the ActiveX interface to directly create an actual Excel file.

Re: using scan from string

aeastet — Thu, 26 Aug 2010 14:03:42 GMT

What do you want it to look like when you send it to Excel? I guess that seems to be the easy question that no one has asked.

Re: using scan from string

raghu670 — Thu, 26 Aug 2010 14:26:01 GMT

I might not be clear while posting my problem.Here is the situation

I am receiving the data from a pressure monitor in the format hr:mm:ss:, -.---,-.---,-.---

-.--- is not constant. it might go to -ve -.--- or even to -.-- format .

I need to used the values -.--- further in my program to make changes to my process and also to store in a file to retrive the data at a later point. So I wanted to copy in a excel file.

So my question is 1) how to get each -.--- value as a separate indicator and 2) how to send each value to an excel or text file.In an excel file I would like to have each value in a separate column.

Hope this explains my situation more clearly,

Thanks,

Raghu

Re: using scan from string

Cory_K — Thu, 26 Aug 2010 15:20:25 GMT

You can use the following regular expression to break up your data.

So you want to write your data to excel?

I would recommend simply building an array and saving it as either "comma delimited" or "tab delimited" text.

You can do this using the "write to spreadsheet file" VI.

Re: using scan from string

smercurio_fc — Thu, 26 Aug 2010 15:54:39 GMT

Cory, your example will not work if only one of the "-.----" location is a number. It's not clear whether or not this can happen, but the impression seems to be that it can.

@raghu670 wrote:

I might not be clear while posting my problem.Here is the situation

I am receiving the data from a pressure monitor in the format hr:mm:ss:, -.---,-.---,-.---

-.--- is not constant. it might go to -ve -.--- or even to -.-- format .

I need to used the values -.--- further in my program to make changes to my process and also to store in a file to retrive the data at a later point. So I wanted to copy in a excel file.

So my question is 1) how to get each -.--- value as a separate indicator and 2) how to send each value to an excel or text file.In an excel file I would like to have each value in a separate column.

Let's review, shall we?

For (1) : IF it's possible that only SOME of the "-.---" values can actually be numbers then use DF Gray's approach:

IF all of the "-.---" values can be numbers then Cory's approach can be used.

For (2): As noted many times, simply feed the string directly to a Write Text File function. You do not need to convert anything, you do not need to split anything. Simply write it out to a text file:

Re: using scan from string

raghu670 — Fri, 17 Sep 2010 19:49:33 GMT

Hi guys,

Thanks for your help.I have tried all your suggestions but came across Match Pattern vi and used it. Now I can save my file as .xls and each data is going into a new cell.It might not be pretty but works for me as I want.

Now I will shift my focus to report generation to create excel workbook.

Thanks again for all your suggestions

Raghu

Re: using scan from string

smercurio_fc — Fri, 17 Sep 2010 20:06:31 GMT

@raghu670 wrote:

Hi guys,

Thanks for your help.I have tried all your suggestions but came across Match Pattern vi and used it. Now I can save my file as .xls and each data is going into a new cell.It might not be pretty but works for me as I want.

Well, if you insist on doing things the hard way, go right ahead...