to measure and save the data of an instrument for a particular time

[vnair@b-phot.org]

Hello frds

the problem might be simple for expertise. However, i am relatively new in labview. I need to measure the data of an optical power meter for some time. for e. g 5min and store this measurment on. txt file. I made a VI. But, I am seeing data in  real time waveformchart. donot getting an idea about how to store this chart data (x and y) in a file . The labview version in our lab is 7 which donot have data logging.

pls help me

[Ranjeet_Singh]

Hi friend,

1. Can you please tell me why you are using text file. Why not database.

2. Is it some kind of command response way. that means when you send command it will respond.

3. What is the logic of only 5 min.

Post your VI then it will be easy to solve the issue.

[moderator1983]

Hi,

You may want to include 'Time-stamp' along with every data-point (sample from the instrument) you read. And after the desired period (in this case 5 minutes), you need to save both in a file (binary or text). Then on reading that file, you'll be able to display the data-points on a 'X-Y Graph'.

The code will look like:

Don't forget to customize the appearance of 'X-axis' display property as shown below.

As you're using LabVEIW version 7.0, I've saved the same code in version 8.0 (I can't further downgrade the code)

[vnair@b-phot.org]

thanks for the reply

1. store/save the data to text file or any format. For e. g .txt file

2.I didn't get. when the instrument command for e. g read instrument execute it will start to measure.

3. suppose for 5min. 5min is not specific. If I need to measure for 4min, 1S etc

The idea is to measure and save the data for a particular time intreval. after that the measurment should automatically stop and save all the data into a file. Need time in x axis and data in y axis.

I am attaching the VI. The VI is not complete. sorry fo that. pls help and solving this for past 3 days

thanks

[vnair@b-phot.org]

thanks for the reply

 I am using Labview 7 and  can't upgrade.(using windows 95, sorry). there is no data logging in labview7. In the function palatte, there is no time stamp also. if no time stamp what will be the option.

Spoiler

Spoiler

thanks

[Ranjeet_Singh]

Thats what I am also saying repeat the loop for that many times i.e. if you are reading the data in 1 sec interval and till 5 min you want to log the data then repeat the loop for 300 times and in the for loop data will be auto-indexed when this will stop data will be automatically written to database.

Here auto index node will store the data untill loop is running. As another person mentioned

Hope it is clear.

[moderator1983]

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vnair@b-phot.org wrote:

In the function palatte, there is no time stamp also. if no time stamp what will be the option.

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Its very much available in LabVIEW 7.

Check here

[Ranjeet_Singh]

Without time it is simply impossible.

There has to be time stamp control.