How to read input data at interval of 15 Minutes for 14days

[Abul]

  Pls, can someone assist me to solve this problem. I am using Lab 2009. My system is having two tanks and two combiners. Combiner 1, combines the input data with the recycled variables data from tank 2.  Combiner 2 combines the output of combiner 1 with the recycled variables data from tank1 and the output of combiner 2 serves as input to tank 1. The input data to combiner 1 is made up of 15 variables as attached (excel file);  X1a, X2a, X3a, X4a, X5a, X6a,X7a, X8a, X9a,X10a,X11a, X12a, X13a,X14a, and Za,. My problems are:

1. To read these input data at interval of 15minutes or input the data at interval of 15minutes up to 14days to the combiner 1 so that the system runs, say at time t=0, input data will be X1a=30, X2a=63.63455, X3a=58.476, X4a=224.352, X5a=31.425, X6a=0, X7a=0, X8a=0, X9a=0, X10a=30.24762, X11a=6.36346, X12a=11.814, X13a=7, X14a=235.6898 and Za=21477.

The next  time t=0.010417 i.e the next 15minute up to the last time t=13.98958.

But X14a terminates at combiner1.

2. To obtain the graph  for  each of the input data  from t=0 to t=13.98959

3. To obtain sum of each variable from t=0 to t=13.98959

4. To obtain the sum of X1g, X2g up to X13g at tank 2 from t=0 to t=13.98959

[Anthony_F · Accepted solution]

Hello Abul,

You could use the read from spreadsheet function to read the data from the spreadsheet. You may need to first export the current data into a CSV file before using this function as LabVIEW can not read Excel files.

From here you can send the array into a waveform graph on the front panel. 

To sum up each variable you should select a column with the index array function and use the add array elements function to get the sum. 

[Jorge_Fernández]

Hello Abul,

When I opened your application I noticed an error saying “Formula Node: Is a member of a cycle”. You are getting this error because your four formula nodes have dependencies among each other. In other words, this application does not follow data flow principles.

From the code you have attached, you may need to have a better overview about LabVIEW data flow programming practices, and there are some good tutorials and examples that can help you understand different architectures that you can put together to achieve what you want.

For example, the following tutorial can teach you how to create and use For Loops and While Loops. This will also help explain timing concepts which you appear to need from the description above. You can also check your LabVIEW shipping examples under Help » Find Examples; I would suggest “Modes for the Timedloop.vi”.

Tutorial: For Loops and While Loops
http://zone.ni.com/devzone/cda/tut/p/id/7588

You will also need to know how to read data from a spreadsheet, which you can learn from this example:
Reading String and Numerical Data from a Spreadsheet File
http://zone.ni.com/devzone/cda/epd/p/id/2235

Feel free to post back if you have any specific questions once you start using these examples.

Thanks!

[Abul]

Thank you all for your contribution.