Problems running example VI with Pico PT104

[Nach]

Hi there.  I have similar problem to this guy

http://forums.ni.com/ni/board/message?board.id=170&message.id=192266&requireLogin=False  

I followed the instructions and could finally get the VI to run.  However, there is still a problem with it.  The temperature readings I get are always 0.00.  Does anyone have an idea on why this is happening?

By the way, the instrument is connected to my pc via PL2303 usb-serial adapter (my pc doesn't have serial ports).  At first I thought the adapter might not work with Labview.  But I did a loopback test using a serial read-write VI from Labview and the adapter seemed to work fine.

[rsw]

Hi,

Thanks for posting the similar links, I'm not sure of how much use I can be from here as we don't have any hardware to test this out with. There are however a few things you can check and a few things I can check from here.

1. Do any of the example VI's for PICO work with this product? - C:\Program Files\Pico Technology\Pico Full\Examples\PT104\example.vi

2. Does device manager and MAX show everything as being installed and working ok?

3. Could you post your code here and LabVIEW Version so I can see whats going on?

All the best,

[DavidJCrawford]

Its possible that the modem lines are not being set correctly to power the PT104.

From the PT104

Pin 7 RTS Held at a positive voltage (>7V) to power the PT-104
Pin 4 DTR Held at a negative voltage (<-7V) to power the PT-104

You can do this using VISA like this



Try it and see if this helps

cheers

David


Message Edited by David Crawford on 02-27-2008 02:05 PM

[Nach]

Rob and David,

I could get readings out of Pico software that came with the unit with no problem at all.  So it seems to me like the instrument doesn't communicate with Labview only.  The picture attached is what I get when I try to open the VISA test panel of this instrument.  (The device status being: VISA returned this device when finding resources, and MAX could use VISA to parse the resource name.  The resource is busy, so MAX could not succesfully open a VISA session to the device.)

I also include the example programs from Pico here.  I'm very new to Labview and have limited experience with instrument i/o so please bear with me.

Cheers.

[DavidJCrawford]

Hi,

That means there is another program accessing the serial port. My guess is that you are running the pico software application at the same time as trying to run the labview example program. This won't work because the pico application has opened the com port preventing any access from labview.

If that is the case, close the pico application and try the pico labview example again.

Let us know how you get on.

David

[Nach]

Oh, sorry for not mentioning this.  But I didn't open Picolog (or any other program) at all when I opened MAX.

[DavidJCrawford]

Are there any other applications running?
   e.g. Hyperterminal
Are you sure the usb-serial is COM5?
   Unplug the USB adapter and check that COM5 disappears in windows device manager or MAX
Perhaps you aborted a labview program that had opened COM5?
   This would leave the COM5 resource in use.
   You can either close labview and try MAX again.
    Or use VISA close like this
   
   then try MAX.
In the example program have you selected the right Port?
   Set the constant Port=5 for COM5

Unfortunately, I don't own a PT104 so I can't try the applcation code here.

I hope this is makes sense. Get back to me if it doesn't.

David




Message Edited by David Crawford on 02-29-2008 09:49 AM