Data Storing and Graphing

[rchaoua]

I am using a cFP-1804 to collect data from analog input devices. I would like to to plot this data then store the measurements to an excel file. I have looked at various KB articles and searched the ni site but cannot find anything useful. I just want to take the current mesurement plot it versus a time increment (I will keep track of individual seconds). The data will be collected over a three day peroid (collected every second) so I would like all data to be graphed. Additionally, I have another set of analog inputs that I request data from every thirty minutes. I would like to store that data in an excel file (just that data and the current time). Does anyone know of any resources out there that perform similar functions? Any help is greatly appreciated. Thanks!

[eek]

The NI Example Finder is also a great place to look for useful material that can help you get started in programming your application. In your case, I would take a look at the FieldPoint examples; there's some vi's that explicitly cover how to acquire signals and log data. Thus, you can piece these vi's together by copy/pasting the code that suits your function. It will also give a better understanding and agood platform on how to code your FieldPoint code from the ground up.

You can find the Example Finder by going to Help>>Find Examples... Once here, you should browse by Directory Structure and expand the FieldPoint folder. The Getting Started folder will cover the data acquisition basics.

You can find example code on how to log your data to file by browsing by Task and exanding the Fundamentals folder. If you take a look at the File Input and Output folder, you'll see you have a wide array of options on how to log data to a file. If you're not sure which one to start with, I would suggest you give Write Text to File.vi a try.

If you want a spreadsheet file, you should search for the Write to Spreadsheet function in LabVIEW to see how you can incorporate this into your data logging code.

This should help you get a better feel for how you can code your application.

Cheers,

Emilie K | National Instruments

[rchaoua]

Thanks for the reply. I actually psoted that message after I had explored those options. Many of the examples did not suit my needs or were slightly beyond me. However,, I spent some time last night search ni.com and found a useful template that meets all of my storing needs. May next question is in regards to program performnce. I plan on storing mesaurements from six diffrent thermcouples every thiry minutes. addtionally, I am storing data from 15 other input analog devices every 15 seconds. Data is being stored in multiple excel spreadsheets. On top of that my labview file is checking controlling the climate in three seperate rooms (ie - monitors and adjusts heaters based on the temperature of each respective room). This program will be running a max three days at a time. My fear is this may be too much for the program to handle and/or my computer may crash during the program. Could I have the opinion of otehrs?

[eek]

I'm glad you found something useful on our website. Do you mind pointing me to where you found the suitable code? I might be able to point programmers to the template in the future.

In regards to your concerns, they are certainly warranted. That's why NI has encorporated the Real-Time System Manager into LabVIEW's functionality. This tool will allow you to monitor the memory usage on your controller as well as on your host. Thus, you may want to test your system out using this tool for a 3-day period to determine whether your system will show any signs of a possible crash. You can even choose to log the specific time your FP controller reaches a critical memory limit, so you'll know exactly when things start to go downhill.

Check it out and see if this helps resolve your concerns.

Cheers,

Emilie