topic Re: help needed-- error code 1815 in LabVIEW

help needed-- error code 1815

gupta.nitesh87 — Mon, 05 May 2008 12:12:33 GMT

i m using 'visa configure serial port' followed by 'visa read' to take input from com1 port. The received signal is spreadhead string. i need to convert it to digital waveform for further processing. there is a VI available for this named 'spreadsheet string to digital.vi'. but while using this VI for the conversion, i m getting an error as given below

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Error -1815 occurred at DTbl Spreadsheet String to Digital.vi

Possible reason(s):

LabVIEW: An invalid character was present in the spreadsheet string. Use only 0, 1, L, H, X, Z, V, or T.

Complete call chain:
     DTbl Spreadsheet String to Digital.vi
     DWDT Spreadsheet String to Digital.vi
     visa read.vi

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I need your help to solve this problem. its very urgent for my project

Message Edited by gupta.nitesh87 on 05-05-2008 07:12 AM

Re: help needed-- error code 1815

MikeS81 — Mon, 05 May 2008 12:19:09 GMT

Hi gupta.nit…,

check your string for the invalid characters. Can you upload your vi, because it´s easier to see what you have done?

Mike

Re: help needed-- error code 1815

Ray.R — Mon, 05 May 2008 12:22:51 GMT

You should try "Spreadsheet string to array". You can set the array to your desired numeric format (ie: Double, etc).

Depending on how you do your acquisition, you may want to build your array until it is ready to be processed, plotted, etc.

RayR

Message Edited by JoeLabView on 05-05-2008 08:22 AM

Re: help needed-- error code 1815

gupta.nitesh87 — Mon, 05 May 2008 13:59:21 GMT

i m uploading the vi here

Re: help needed-- error code 1815

MikeS81 — Mon, 05 May 2008 14:05:06 GMT

Hi gupta.nit,

i thought you can upload the vi in the same configuration as you use it, can you? I see no "Spreadsheet String to digital" function. Can you upload it with some characters you have already received?

Mike

Re: help needed-- error code 1815

gupta.nitesh87 — Mon, 05 May 2008 15:59:29 GMT

sorry mike. that was my mistake.

now i m uploadig correct vi.

Re: help needed-- error code 1815

gupta.nitesh87 — Mon, 05 May 2008 16:17:24 GMT

One more thing I want to tell is like our data is coming from a microcontroller that is sending all 000-FFF and without ant delimiter. So suggest any other visa read vi which can directlr take in binary or as byte instead of reading it as string.

Re: help needed-- error code 1815

smercurio_fc — Mon, 05 May 2008 16:29:22 GMT

There is only 1 VISA Read, and it returns a string. It's up to you to deal with that string. You state:

our data is coming from a microcontroller that is sending all 000-FFF and without ant delimiter

So why are you trying to use the Spreadsheet String to Digital Waveform VI? If you have no delimiters, then that VI won't work.

It seems to me that what you actually want to do is typecast the data recveived from the microcontroller as an array of numbers. You did not provide a sample of what you're actually receiving from the microcontoller.

Re: help needed-- error code 1815

gupta.nitesh87 — Mon, 05 May 2008 16:55:49 GMT

Actually we dont want it in string its just that we found only VISA read VI to take data from device connected through com1 port which stores in buffer as string by default. What we are recieving is a signal recording some heart beat pulses and we want to have it displayed in amplitude time graph. When we are seeing on other oscilloscope programs its showing nicely but we are facing problem in labview possiblly due to these data format mismatch. Its showing YYYYYYYYYY in read buffer and when we are tring to convert in byte array and converting in digital waveform it gives Error -1815 occurred at DTbl Spreadsheet String to Digital.vi LabVIEW: An invalid character was present in the spreadsheet string. Use only 0, 1, L, H, X, Z, V, or T.

Re: help needed-- error code 1815

Ray.R — Mon, 05 May 2008 17:01:15 GMT

If you are getting strings of "YYY", the it doesn't meet the criteria. You can only use 0, 1, L, H, X, Z, V, or T.

So as Smercurio stated, you cannot use the Spreadsheet string to Digital waveform. You have to deal with the string in a different manner.

Use the VISA Read to get the serial data. But you must then handle that before you try to plot it.

In order for anyone to propose something, we would need to see an unmodified version of the received string straight from the serial port. You could save it in a text or binary file, whichever is more appropriate and post it in this thread. 🙂

Message Edited by JoeLabView on 05-05-2008 01:01 PM