Lookup values

[AzeoTech]

Question:

i have the lab jack U3 HV and have bought a license for Daqfactory.
 

i want to control an output to a electronic pressure regulator based
on a voltage contained in a column of values against a column of time increments (currently in excel)
 

i would really appreciate some advice and perhaps you could point me
at some information etc that would help me with this.

Answer:

Sounds like you want to use a lookup table?  First, you'll need to load the document from excel.  That requires only a few lines of script.  But first you have to save your Excel document as a CSV file.  Then the script is:

private handle = file.open("c:\data\myFile.csv",1,0,0,1)
global lookup = file.readDelim(handle, -1, ",", chr(10), -1)
file.close(handle)

If you have a header row, add a file.read(handle) above the global lookup... line.

Now your file is in the lookup variable accessible from anywhere.  To lookup a value, use the search() function.  Lets say that you want to look up a value in the first column of the excel spreadsheet and that column is listed in numeric order from smallest to largest.  You'd do something like:

private index = search(lookup[][0] >= val)

where val is the value you are looking up.  Then use index to retrieve the corresponding value in the second column:

lookup[index][1]

[Vweber]

I am trying to do something similar to the above on LJ T7 pro.  Twice per day I want to log a value from a temperature sensor.  Then I want to operate some valves based om the logged data.  Is there a way to script this without going to excel?  I know how to write the valve script in terms of usung a set value that I write in (when Itake the temp data and log it in my head as say 73 deg, I set the valves to function off this data.). 

Much easier to script it to automate that for me but not sure how.

 

vic

[AzeoTech]

Excel was used in the original post simply as a quick way to generate the table.  What you describe isn't a lookup table, just an evaluate of a value.  Since the value is already in DAQFactory, you can just do the calculation right when you log it.  To log it you might use an export set with [0] in the expression.  Then you might do something like:

while(1)
   delay(43200) // wait half a day
   beginexport(myExport)
   if (temperature[0] < 73)
      valve = 1
   else
      valve = 0
   endif
endwhile