Reading and Storing Temperature

[rchaoua]

Hello,

I am new to LabVIEW programming. I have jsut purchased the cFP-1804 and TC-120. My goal is to read the 8 thermocouple temperatures simulateneously, display that data on screen and store it in an excel file. Currently, I am trying to just read the thermocouples. I have started out with one to keep things simple. I was able to read the temperature in MAX when I tested the channel. I figured al I needed to do was go to the the block diagram of my project go to Express>>Input>>Fieldpoint. This brings up the configure Fieldpoint window I browse and find the channel I want to use and wire the value out area to a numeric indicator. However when I run it I get the "Error 32812 occurred at FP Read.vi". I have searched the forums and don't quite understand the KB articles. I would figure if I went through the configure FieldPoint window it would have performed all of the work for me.

So, my first question is, Am I performing the read operation with the correct VI? I would ideally like to have just have indicators on the front panel and not have to insert the iak file name and the other information associated (ie - have all of this information preprogrammed).

Is there an easy way to wire a button to the VI to initiate the temperature being read? There does not seem to be a place to wire a boolean button to the Express>>Input>FieldPOint VI I've chosen.

Any help is greatly appreciated.

[mikeporter]

My first recommendation is to forget the Express VIs. It's better to learn how to do simple tasks like this yourself. Hence, my second piece of advice is to check the examples that ship with LV. Your application is a straight-forward data logging example. You will find the pieces there to build what you need.

Mike...

[rchaoua]

I will try that. I was inder the assumption that if you have a fieldpoint device you should be using the FieldPoint VI's. But if it is simpler to complete the tasks I need to do another way I will do that. I do recall that LV Getting Started has some examples of using I/O instruments. I will take a look. Any other tips and suggestions?

[RDR]

The FieldPoint shipping examples utilize the FieldPoint VIs and will help you get started with your application.  I recommend looking at 'Temperature Measurement.vi' (I attached a screenshot of the front panel).  Cheers!

[rchaoua]

I tried the Instrument IO Assistant put I get a prompt telling me that MAX or Instrument IO assistant is not isntalled correctly. I have these install CD's at work so I can't check and see if that is the problem. I am sure MAX is installed correcly b/c I have been using it. Is the instrument IO assistant an add on?

Since I cannot use the Instruement IO Assistant I thought I would try my luck with the FieldPoint VI's. I was unable to find any example VI's that shipped with the FieldPoint.

But I did wire up a program that I was sure to work. I wanted to read a single thermocouple. So I wired a FieldPoint IO vi to the FR Read (polymorphic) vi which in turn connect to a Waveform chart. I just wanted this to run conitnuously, so, I put a while loop around it to run.

Upon starting the program I get the error: "Error 32812 occurred at FP Read.vi"

I searched the forums for why this error could have occured and tried the fix  the knowledge base article (Why Do I Get Error 32812 From Some FieldPoint Modules But Not Others?) gave. The fix basically says to go into MAX and click "Find Devices" I did that and it did not help. Anyone have any expreience with this error? I would greatly appreciate the help.

The funny thing is I can write to my DO-400 module without any errors but not the TC-120 (I am trying to read from).

Thanks

[rchaoua]

Also, I was able to run the Temperature Measurement.vi example that was shipped with FieldPoint and still received the error 32812 when I ran it. I have tried several different examples and they all give me the same error. I also get this message when I try to read analog inputs from the AI-112. ANy help on resolving this error is greatly appreciated.

Message Edited by rchaoua on 10-16-2007 07:13 PM

[rchaoua]

Either I am extremly dim-witted or a genius...I have fixed my error 32812 error by closing MAX when I run my LV programs. After that it worked. Thanks for all of your help!

[RDR]

The Instrument I/O Assistant error will most likely be solved through this KnowledgeBase:

http://digital.ni.com/public.nsf/allkb/DC808866AF7D5C0986256FCE006E9BAB?OpenDocument

Additionally, the 32812 error you are experiencing will most likely be solved permanently through this KnowledgeBase:

http://digital.ni.com/public.nsf/allkb/9DB72AFCBC02D7D986256FC10055D65B

The FieldPoint Examples can be found by going to Help>>Find Examples, then from the 'Browse' tab navigate to Hardware Input and Output>>FieldPoint to find the shipping examples for FieldPoint.  Cheers!