Scan from string with %g - result not accurate

I am trying to use the "Scan from String" VI to convert a string into a number. I am using "%g" as the format specifier. The conversion is only grabbing the first six significant digits, yet I need it grab all significant digits. Is there a real limitation here? What could I do to solve this issue?
I have attached a simple VI to demonstrate what I'm seeing.
Thanks,
Joel
Attachments:
Scan_from_String_Example.vi ‏7 KB

It is because the display format for your numeric indicator is set for 6 significant digits. Adjust the display format for the indicator and you will see that the other digits are there.

Similar Messages

Scan from string in pda

Hello.
I work with LV 7.1, with the I Modul of PDA.
It doesn't work me 'Scan From String'. I have not found any contradiction because the pda doesn't accept it.
Does somebody know which the cause can be? As I can substitute it?
Thank you.
Greta
Attachments:
scan from string.JPG ‏6 KB

Hello Greta
The Scan from string function is supported in LV PDA but with some restrictions. The help file for LV PDA tells us:
'The Format Into String function and the Scan From String function do not support changing the numeric separator (such as %#;). The Scan From String function does not support wildcard matches.'
You are changing the numeric separator and this is not supported.
Hope this helps
BelenS

Error scan from string

Hello, i have a problem with Labview 2013, on my pc(where i make the Vi from zero) work verry good, but when i put the Vi on laptop with the same version of labview, i get error from scan from string. hardware part are not changed, why i get this error? this is my VI.
Attachments:
Dc_motor_control2.vi ‏365 KB

Put some probes or indicators to see what is being returned from the VISA Read. It could be a simple synchronization error. Try reading more bytes.
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Unofficial Forum Rules and Guidelines

Regular expression for Scan from String

I am trying to pick out three numbers with pattern $number1:number2:number3# from a stream, for instance 8.559509#$-1.686432:-2.427051:-7.281153#$-6.160924:-1.763356:
So far, I use "Scan from String" with Format string "$%f:%f:%f #". However I don't know how to ignore/delete the items before $. Would you like to help me with that? Cheers

You know that your sequence of numbers begins with the $ and ends with the #, so you can separate them into groups first, then separate each number out.
Bill
(Mid-Level minion.)
My support system ensures that I don't look totally incompetent.
Proud to say that I've progressed beyond knowing just enough to be dangerous. I now know enough to know that I have no clue about anything at all.

Scan from string to timestamp not working

Hi,
I have a problem with the "Scan from string".
The format string "%<%H:%M:%S%ds%bs%y>T"
works for the input string "11:12:1322sJans2010"
but doesn't work for the input string "11:12:1322sFebs2010"
The only difference is the month (Jan or Feb). I got know idea why!
Could anyone help me?
Regards,
Marcelo
Attachments:
dateString.vi ‏6 KB
date.PNG ‏5 KB

Both work for me in LabVIEW 2009; perhaps this was a bug in 8.6 that's been fixed?
Also, is it possible your operating system is running a different language, in which Jan is the abbreviated form of January but February is something else?

"scan from string" to timestamp doesn't work for 18:00:00 (6PM)

I just found a strange issue in LabVIEW. I hope I'm doing something silly, but I just may have found an unusual bug.
run the snippet below with the following for the input string: 03:00:00,18:00:00,17:00:00
Time converts fine for just about any other time EXCEPT 18:00:00 (6 PM) for which it is returned as 00:00:00 (midnight). If you even add a second to it (18:00:01) you get back the expected result.
Here's hoping I'm not loosing my mind
Matt Holt
Certified LabVIEW Architect
Solved!
Go to Solution.
Attachments:
TimeParseBug.vi ‏11 KB

As annoying as it may seem, this exact scenario is an abuse of the timestamp. A timestamp is meant to be used for absolute times. And that includes a date. As Ravens Fan already pointed out, the 0 seconds since January 1, 1904 GMT is used in all timestamp display routines to mean the canonical invalid timestamp and hence the timestamp control displays the default string indicating the actual date/time format rather than a specific date/time.
If you need an absolute timestamp, for instance because you do want to have a local time indication, although the date is not relevant, adding an offset of 86400 to all values would fix it once and for all. Now the timezone offset can't cause the timestamp to reach 0 ever, even if you reside west of GMT, and it will be fine (until you start to do timestamp arithmetic that involves subtraction of relative timespans, then you would have to make the offset big enough that this will never get an issue). The current date would serve as a nice offset for that, which would be MattH's last suggestion. Nice to see that the Scan from String routine actually does use the passed in timestamp as default value and only replaces the values it is configured to parse.
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

Why am I getting error 85 from 'scan from string' VI?

Data is in CSV format from an Excel spreadsheet. It may be an empty string but I compare the data to an empty string and, if is empty, then I input the string constant '0' to the 'Scan from String' VI. I'm using 3 probes to try to debug this.
The 1st probe is at the output of an 'Index Array' VI which extracts the element of interest from the array loaded from the spreadsheet file. The probe declares it's type as 'string' and the probe content is blank. I assumed that this means 'empty string'.
The second probe is at the output of an 'Equal' VI which compares the data described above with the empty string constant "". The result is False. Why is this? How do I tell what the CSV data is? If the probe is blank can it be a Null character or NaN or is it interpretted as a blank string? The Excel file has all fields defined as 'text.
The third probe is also blank.
When the data is interpretted by the 'Scan from String' VI it fails. I also have the default pin wired to a double constant with a value of o. Shouldn't this be used by the VI in the event the VI can't interpret the string passed to it?
Thanks for any help,
Frank

fr@nk wrote:
The second probe is at the output of an 'Equal' VI which compares the data described above with the empty string constant "". The result is False. Why is this? How do I tell what the CSV data is? If the probe is blank can it be a Null character or NaN or is it interpretted as a blank string? The Excel file has all fields defined as 'text.
Yes, it can be a Null character. NaN is something else. To really see what's there you can place an indicator and then change the display mode of the string indicator to Hex Display Mode.
You have not indicated what your format string is. Why don't you upload your code along with your data. Just out of curiosity, what are you using to read the file? Are you using Read From Spreadsheet File?

I can't scan from my HP Photosmart C4440; not direct from the scanner to pc nor vice versa

I can't scan from my HP Photosmart C4440; not direct from the scanner to pc nor vice versa, Please help me ASAP, Thanks everyone, I'm stuck with a homework!

Hello @Roberto3 , and welcome to the HP Forums, I hope you enjoy your experience!
I see you are having issues scanning. I'd like to help!
Are you able to make a copy as opposed to a scan?
Do you have any errors come up when scanning?
I'd recommend starting with a power reset. Disconnect the power cord from the printer and the power outlet, then wait 60 seconds. After 60 seconds, plug the printer back in. Ensure you plug the printer directly to a wall outlet. Make sure to bypass any sort of surge protector or power bar.
I would also recommend downloading and running the HP Print and Scan Doctor.
Good luck and please let me know the results of your troubleshooting steps. Thank you for posting on the HP Forums!
Please click “Accept as Solution " if you feel my post solved your issue, it will help others find the solution.
Click the “Kudos, Thumbs Up" on the right to say “Thanks" for helping!
Jamieson
I work on behalf of HP
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Scan from string error 85

Hi Everybody,
I'm trying to use LabView to
process some data.  The data, although it was collected via labview,
has been written out to csv file format.  I have been able to
successfully open the file and use the search split string function to
remove the "header" from the data stream.  Now I'm trying to parse the
header to extract some pieces of the info that is there.  I'm trying to
do this with the Scan from String VI.
So
far I've been able to retrieve the Specimen ID from the first line of
the header by setting the format string input of Scan from String as
"Specimen ID ,%s", which works just fine.  Problem is, when I
adjust
the format string to include the next piece of data I want, I
inevitably get an Error 85, which is a failed scan. In fact, I
get an err85 every time I try to extract something from after the
second line. I've attached a VI in which I cut and pasted an
example header string in as a string constant and an example of how I'm
trying to extract the values. I've tried playing around with
spaces and different formats, but get the err85 no matter what I do
(unless I extract the first line). I have a hunch that it has
something to do with the EOL marker, but no idea how to work around it.
A search of posts here show that a lot of people have issues with the
scan from string vi, but nobody I could find had this exact
problem. I've also considered using the spreadsheet spring to
array function, but because I have a mix of commas and EOLs it doesn't
seem to work either. HELP! I really don't want to have to write this
over in VBA/Excel.
Thanks,
Turk
Message Edited by YoungTurk on 07-29-2005 10:36 AM
Attachments:
Scan.vi ‏12 KB

You should probably parse it line by line (See attached, LabVIEW 7.1)..
The attached example shows one possibility to get all the Items and values out. Not all values are strictly numeric so you would need to adapt the code a little bit. (This is just a very rough 1 minute draft).
You might want to cosider to extract all values into a cluster for further processing, Have a look at the example posted in this thread . It can be easily adapted to read the values in the proper format (DBL, I32, Date, String, etc.) depending on the item name.
Good luck!
LabVIEW Champion . Do more with less code and in less time .
Attachments:
ScanMOD.vi ‏30 KB

Wrong use of "Scan From String" function in a while loop?

Hi,
I've got a "Scan From String" function inside a while loop. On the first iteration it converts correctly the number passed by the input string (for example 4) But on the second one it has only spaces (one or more \s) as input string.
I expected to obtain a zero as output (as it does always that it can not make any conversions, as I am supposed to) but indeed, i subtracts 1 from the previous number (according to the number indicated as example I would obtain a 3 as output)
What's wrong with this?
Does the function fails on this case?
The rest of the diagram o the VI is expected to manage a 0 on that situation, like others in which the conversion is not made.
Andres.

I have simplified the VI evading calls to other VIs and trying to reproduce the mistake.
The type of string I introduce to reproduce the mistake is:
clock 3 (30) clock (40)
Forgetting to introduce a number between the second "clock" and the following parenthesis, I would manage it programmatically with code that isn't included.
Then "Scan From String" is supposed to do not make a conversion. But it leaves a 2 as output (in this example)
I have realised, unbelievable but true, that it has matter with the number I substract to the output number (if it were 2, I would obtain 1 as output and so on)
Excluding that, I got the conversion made before as output, 3, on the second time that "Scan From String" executes. But, how can this func
tion as bad?
I am using LV4 on an old PC. I have tried to reproduce it with LV6 and it works. But it isn't desirable for me, I would have to convert a lot of VIs and surely I will find a lot of errors due to the conversion (I have already tried)
Attachments:
EXTCLOCK.VI ‏26 KB

Scan From String White Space

i all,
I'm trying to use Scan From String in order to parse some data coming in from UDP.
Input String: ASCII [00 01 02 03 ... FF]
What I want: s[00 .. 30] d[12], d[34], d[56] leftover s[37 38 39 ... FF]
ATTEMPT1
Format String: %49s%2d%2d%2d
What I get: s[00-09] RUNTIME ERROR!
ATTEMPT2
Format String: %49[^]%2d%2d%2d
What I get: Only allows first output. Will error out if I use any additional outputs from Scan From String
ATTEMPT3
Format String: %49[^(0xFF)]%2d%2d%2d Value in () is ASCII character FF.
What I get: s[00 .. 30] d[12], d[34], d[56] leftover s[37 38 39 ... FF]
It appears as though when I use %##[^] it thinks I'm looking for the ENTIRE string so it will not let me add any more Formatting. If I add a delimiter other than ^ it will run, and it will work presuming that character isn't within the first 49 characters... and I can't guarentee that it won't.
I'm aware I can parse my string using subsets and whatnot... but Scan From String is so elegant. It would be great if %S allowed for white space... or if $##[^] would simply take the first ## characters and allow me to Format after that.
Is there a simple, elegant way to do this? I wish my dataset was only 3-4 outputs. It'd be ideal if I could. Thanks.
Edit:
It might be more helpful if I provide a less abstract example:
I have an ASCII Header (Finite Length String), a Sender IP (Finite Length String), a Timestamp, a Message ID (Finite Length Decimal), A Message in ASCII ( '1' actually means 0x31, not 0x01) And for some ungodly reason... no delimiters.
So I was HOPING %##s%##s%<%H:%M:%s>t%##d (With leftover string to be my message) would work, but if any white space is contained within there... it messes up.

I cannot provide exact strings because the string is actually ASCII characters, most of which aren't displayable.
I have a string where I have:
24 ASCII Characters representing 6x U32 Header Data
13 ASCII characters represening the sender IP (string)
12 ASCII Characters representing the name of the message (String)
12 ASCII Characters representing 3x U32 Data
12 ASCII Characters represneting the name of packet (String)
12 ASCII Characters representing 12x U8 Data
256 ASCII Characters represening 256x U8 Data
etc...
It would be ideal to simply Scan from the string and output the data with the appropriate data types already assigned instead of splitting string and type casting each individualy. But if, for example, my header starts with an ASCII representation of a U32 of 2560(decimal) it would look like this: [00][00][0A][00]. ASCII 0A is considered white space. So my header would only contain 2 ASCII characters instead of the desired 24.

Error 1 occurred at Scan From String (arg 1)

I am communicating with the AT Trainer 5000 via serial port to USB converter.
I installed all drivers of converter successfully and it is shown in MAX as com port. I also installed VISA software.
I am using labview 2013 version.
When I connect the hardware to PC via usb to serial converter, try to run the program for seeing of real time graphs, I am receiving this error Error 1 occurred at Scan From String (arg 1) whereas there is no waveform shown in waveform chart.
Also read buffer didn't show an incoming data at read buffer.
Other details for this error is
Possible reason(s):
LabVIEW: An input parameter is invalid. For example if the input is a path, the path might contain a character not allowed by the OS such as ? or @.
Also pics of error is:
Program is also attached. Please checked the also.
Expert please help me how to get rid of this error.
Attachments:
Project.vi ‏23 KB

Since you are using the termination character, you should not use the Bytes At Port property node. Just set the number of bytes to read for the VISA Read to something really high (larger than what you expect in a single transmission). The VISA Read will stop reading once the termination character is reached.
Now, what is the format of the data coming from the instrument? I see you are converting an ASCII Hex string into a number while trying to also turn it into a double. That is likely why you are getting your error.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions

How do I avoid Error 85 in Scan From String scanning VISA read buffer?

I have encountered an Error 85 with my Scan From String VI. I have a timed
loop to read data from a device (flowmeter) using a serial port. This device takes
periodic measurements and sends the reading which contains a numerical value to the serial port COM1. It cannot be read continuously, and the period
between measurements may vary, so I decided a timed loop would be better than a while loop.
The VI begins with VISA Configure Serial Port and then
goes to a VISA Write which sends the message to the device to begin
taking measurements. After this, the device usually says "TAKE FLOWMETER READINGS" to the terminal, thereafter only sending numbers. Then begins my timed loop containing VISA Read. I
am taking the read buffer two places.
First, I am taking it to an Array to Spreadsheet String with the
Format String %.3f, as was in the Write to Text File example. Then I am
using Concatenate Strings with this string and also a string containing
the System Time. This string goes to Write to Text File, which I have
configured using Open/Create/Replace File outside of the loop.
Second, I am taking the read buffer to a waveform chart. I thought
it would be a good idea to use Scan From String to convert the string
into a DBL which I am then sending to the waveform
chart.
I am not sure if the initial "TAKE READINGS" message is giving me an error. I was able to get one reading saved to my text file from the device.
Also the format string for my Scan From String is %.3f
I am getting the Error 85 at the Scan From String only sometimes.
When this happens, there is no data being written to the text file. But
other times, I get data and it writes to the text file just fine (but
rounds to nearest whole number).
Any help would be greatly appreciated! This serial port device has been giving me a lot of trouble.

Is this what you mean? Did I wire the shift registers correctly?
I didn't know if you meant to Concatenate before Scan From String or Concantenate before or after VISA Read?
Message Edited by YeungJohn on 11-20-2008 03:48 PM
Message Edited by YeungJohn on 11-20-2008 03:49 PM
Attachments:
SerialShiftVI.JPG ‏87 KB

Scan from string and extract string between delimiter

Hello,
Basic questions. Is it possible with the scan from string regular expression to extract the string that are within the specified delimiters. Here is an example:
\\Name of folder 1\Name of folder 2\Name of folder 3\File Name
Can the scan from string output the following by specifying the right regular expression:
Name of folder 1
Name of folder 2
Name of folder 3
File Name
I have tried \\\\%s\\%s\\%s\\%s but the %s stops at the first white space.
Thanks,
Michel
Solved!
Go to Solution.

RavensFan suggested the appropriate function for your requirement, however you can also use an alternative, which is 'Spreadsheet String To Array'.
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Scan from String (arg1) in TKTDS1k2K, Input parameter invalid

After calibration, i am getting a error about Command Requires GPIB controller to be controller in charge, and Scan from String (arg 1) in TKTDs1K2K scalewaveformarray.vi>scope_vppmeaurement.vi
LABVIEW: An input parameter is invalid.
NI-488: Commands Requires GPIB Controller to be in charge .
This program was working before 3rd party calibrated. Failing on first scope measurement. Passes Scope Setup.
Thanks from newbie scheduled a May Class.
Greg Shepherd
RUNNING tEST STAND & lABVIEW 8
Greg

One additional note. I have not had to use Regular Expressions very much, so I'm somewhat of a novice. My FIRST attempt to match either the Verbose or Abbreviated commands from the DSO was as follows:
:WFMP.*:XZE.* $
In words, what I’m trying to say is, “Match any instance of “:WFMP”, followed by any number of any character, followed by “:XZE” followed by any number of any character, and ending with a Space character.” It sure seemed like that should work...but it did not within the VI. That was when I tried other options and found the longer, "A or B" type of match would work, as described in my previous post.
This morning, a buddy sent me links to a couple of websites where you can experiment with Regular Expressions and see if your input is getting matched correctly. By using one of those tools, it appears that my initial attempt IS VALID, but yet, it didn't work within LabVIEW (8.6 for me). I have read some other posts RE: "Bugs" within the way LabVIEW works with Regular Expressions, so maybe this is something similar. But at least I'm up and running by using the long-way.

Scan from string with %g - result not accurate

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