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PT104 with Labview 8.0

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PT104 with Labview 8.0

Postby NR » Tue Feb 26, 2008 3:34 pm

I have trouble getting Labview example to work (similar problem to http://www.picotech.com/support/about3212.html). Up to this point I can make the VI to recognise the call library function and run it. However, the temperature readings are always 0.00 Can anyone tell me why this is happening?

Btw, I use PL2303 usb-serial adapter to connect the instrument with my pc since it has no serial ports. I did a loop back test on Labview and the adapter works fine.

Cheers.
NR
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Postby gruntman » Tue Feb 26, 2008 4:43 pm

NR,

I apologize for the fact that you are having issues with one of our examples. If the program is constantly returning 0.00 it is due to the program not communicating with the PT-104. Does it return 0.00 when you first open the program or only after you stop the program and try to rerun it? If this is the case delete the function "pt104_close_unit-2" from the block diagram. With serial ports it is not an actual requirement to 'close the port' anymore. The ports will be automatically closed as soon as the application is exited (whether this be your Labview development program or your finalized program). Once you take this call out you should be able to rerun the vi multiple times without having to close the program. If it is returning 0.00 when you first start the program double check the port settings and the compatibility of the USB-Serial converter by attempting to log with the PicoLog software. Let me know if this works out for you or if you have any other questions.

Regards,

Richard Boyd
Crag Technologies, Inc
http://www.pc-oscilloscopes.com
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Postby NR » Tue Feb 26, 2008 9:41 pm

gruntman,

The temperature shows up correctly in Picolog. So I guess there shouldn't be any problem with the usb adapter. But in Labview example, it always return 0.00 no matter if it's the first time I run the programme or rerun it. :(
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Postby gruntman » Wed Feb 27, 2008 7:44 pm

NR,

Let me know if the attached example works on your computer...

Regards,

Richard Boyd
Crag Technologies, Inc
http://www.pc-oscilloscopes.com
Attachments
PT104.vi
PT-104 VI
(73.02 KiB) Downloaded 265 times
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Postby NR » Thu Feb 28, 2008 4:34 pm

Thank you for your programme. I'm sorry to say this but the programme still doesn't work on my pc (always get a 1). -___-"

Actually the numbers did show up during one of the tests without me doing any change to the programme. However I couldn't get it to work again. That was very weird. :shock:
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Postby gruntman » Fri Feb 29, 2008 12:05 am

NR,

The program will display a 1 is you have nothing connected to that channel. You are using a PT100 sensor when you are testing this aren't you? Also, there will be a delay (depending on the computer up to 30 seconds) when you first start the program and the computer opens the com port and connects to the data logger. Maybe this is your issue? Also, wire a indicator into the output of the open_unit call; when you first open up Labview and run the program this call should return 1 to indicate that the computer is connected to the data logger. If you stop the program and restart it this indicator will return 0 as the com port is already open.

Regards,

Richard Boyd
Crag Technologies, Inc
http://www.pc-oscilloscopes.com
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