compact fieldpoint

[0807]

Hi,

I am doing a project for my school but i encounter some problem with the field point and i cant solve it.

I am using the real time compact field point with the analog input terminal to measure current from a 500W lamp using the ASM 010 current transformer which the output of the transformer is 7.5 mV but i am converting it to current using a maths calculation.but what i get from the reading is bascally juz noise interuption which i cant get the exact values. i have input 2 picture in the attachnment just want to know whether i did the correct thing

thanks

regards

jackson

[Graziano]

Hi!
   The two picture you attached are not enough to see your code, so please, can you post your code?

   I have a feeling that the input conditioning is connected in some misfunctioning way, but first, let's see for first if code is correct (is the easyest thing to do on the internet ), otherwise you'd post the schematic of input circuitry and connection to your input module.

graziano

[0807]

ohh ok thanks for replying. the 1st attachnment current and temp test is my main VI and the other 2 is my sub VIs can take a look...thanks

[Graziano]

Hi!
   Since I don't work with Analog Input devices, (I use Digital IO), I exactly don't know the meaning of "Read FP"  function with an array of double as output, but I suspect that it is an array with all channels grouped, i.e. you have to select "1" in "index array" to read channel 1 data (your top fieldpoint IO point is set to channel 1).

   Where have you attached your instument? To channel 0 or channel 1?

   I suggest to wire the error cluster and see if an error is generated from read function....

   I'm really sorry, but I don't know AI modules, I can only guess the behavior......

graziano

[Graziano]

Hi!
   I've dopne little modifications, just take a look at them... don't look at my stile, I coded in about 1 minute, because I'm a litle busy today to do stylish things...

   Maybe this can help.... please, let me know! Have a nice day!

graziano

PS.: aI almost forgave... which version of labView are you using? This is LV 7.1.  If you have 7.0 you won't be able to open it, so I'll convert.


Message Edited by Graziano on 01-11-2008 07:08 AM

[0807]

hi

thanks for everything..shall tell whether it works anot...thanks

[0807]

hi

opps forgot to tell you that the calculation VI with the temperature is working is just that the current calculation is not working..i cant get the reading form my main VI

[Wayne.C]

0807,

Here is another tip for your code.  FPRead by default outputs a 1D array of readings.  It is also polymorphic.   If you connect the "type" terminal on the FPRead to a numeric constant, FPRead will output data of that type and you won't need to index the arrays any more.  I have attached an image that shows this. 

[Graziano]

Hi!
   I don't understand... is the VI for calculation of current that doesn't work, or is it the Fieldpoint read function (circled in red) that doesn't work? Are you getting the right value from it?  The Vi seems to work, I don't know the meaning of constants used in calculation, but it seems to work! Maybe you are not reading the good value? Or input is wired wrong way....

graziano





Message Edited by Graziano on 01-11-2008 07:48 AM

[Wayne.C]

0807,

Is the current that you are measuring AC or DC?  This will make a huge difference in how it is measured.