yes.. actually application is to test the system fo 15 to 20 day.. thats why..
currently im getting this data in excel im attaching here
using line breaks in your data sent to Arduino and echoed back makes it even worse…
Again the advice: don't send data each second (unless you need to)!
Another advice: use a standard delimiter between your data items. "-----" isn't standard, but TAB or semicolon is…
When you want to analyze such "big" data files you should not use Excel. It's not made for this task!
THIS IS NOT AN EXCEL FILE! Excel uses a (formerly proprietary, now only semi-proprietary) format that includes Graphs, formatting, formulas, etc. Excel (the Microsoft program) can also read a plain text file that is "formatted" into rows and columns by having commas separating column entries and New Lines separating rows -- this file format is called "Comma-separated Variables", or .csv. Excel can read such a file and, internally, treat it as a spreadsheet that you can add in the other Excel properties (such as graphs, formatting, etc.), but then you must save it as an Excel file in an Excel format (which start with .xl, as .xls, .xlsx, etc).
As an ordinary text file, the size of the file is limited by the size of your free space on disk (remembering that it is a text file, and thus larger than the size of the data you are writing). You also require enough memory to hold all the data before writing it, though you can do partial (even line-at-a-time) writes.
how to save incoming serial string data in excel??
you already save your data in spreadsheet files (aka CSV files aka formatted text files)!
So what exactly is your problem?
We already gave you answers - did you (re-)think your program design based on them?
after writing the data with some better formatting (I gave you suggestions before) you could use tools like Diadem, Matlab, LabVIEW, Origin (and many more) to analyze your data…
We don't know all of your requirements, so how can we give specific software recommendations?
it seems im very poor in labview
.. so can anybody suggest me, how to save incoming serial string data in excel??
Your problem isn't that you are "very poor in LabVIEW", but perhaps English is not your first language, and you haven't clearly understood the comments and suggestions we've tried to make. Here is a summary:
Consider writing two or three small programs -- don't try to do "everything all at once". Write a little routine that just gets serial data from your device and displays it on the screen. Work on this until you are confident that you are getting the data reliably. Write a second little routine that uses something like a random number generator to "make up" fake data that resembles the data you would get from your instrument. Using a Wait function inside your loop, generate new data once a second, and pass it to a routine that writes it to a Spreadsheet File (or whatever output format you choose). Work on this little routine until you know that you have the "file saving" piece working perfectly, and know that you can take a week's worth of data without worry.
Once you have these two little pieces working, put them together!
In your "spare time", think about what sort of data analysis you want to do with your output file.