How to get correct voltage reading?

[astroboy]

Currently I am using PCL-818 DAS card from Advantech. Advantech's test program shows value correctly and I compare it with the multimeter. Problem is that I cannot get them correctly. For eg. The actual reads 5V but the indicator on front panel reads 0.09V instead. I used Advantech's AIVoltageIn.vi. What are the right adjustments I should apply on the Numeric Indicator's properties?

[Bill B]

Hello Astroboy,

Thank you for contacting National Instruments.

It appears that there is an issue with Advantech's AIVoltageIn.vi. If you are supposed to be measuring a 5V signal, and this VI is returning the number 0.09V then there is definitely a problem with either your DAS card or the driver that their VI is calling to return the measurement value.

Unfortunately, there is really nothing you can do to correct this problem in LabVIEW other than try to scale the data to display correctly. Even in that case, you will need to know that factor of which the measurement is incorrect. More than likely you will need to contact Advantech in order to resolve the issue with the DAQ device.
If you would like, you can check out our full line of Data Acquisition bo
ards that will work seamlessly with LabVIEW.

http://www.ni.com/daq

Please let me know if you have any additional questions. If you get your hardware problem solved, I can help you with any LabVIEW questions you may have. Also, if you have any questions about our Data Acquisition boards, I will be more than willing to answer any questions.

Regards,
Bill B
Applications Engineer
National Instruments"

[rolfk]

astroboy wrote:
> Currently I am using PCL-818 DAS card from Advantech. Advantech's test
> program shows value correctly and I compare it with the multimeter.
> Problem is that I cannot get them correctly. For eg. The actual reads
> 5V but the indicator on front panel reads 0.09V instead. I used
> Advantech's AIVoltageIn.vi. What are the right adjustments I should
> apply on the Numeric Indicator's properties?

I had to deal once with an Advantech card and I think you had to first
configure it for a certain input range, which depends on the card you
are using, or maybe jumbers on it :-(. Your problem looks very much like
the card is configured to read for instance 0 - 10 V but the software
believes the card is set to -5 - +5 V.

Of course the configuration param
eter on that VI was just a number 0, 1,
2, 3, 4, etc so it was not very user friendly and in that particular
case I just played around a bit until I got the correct measurements.
I told however the guy asking me to show him how to get the card
running, that I didn't very much like this driver and that I feel a LOT
more comfortable to program with NI-DAQ than this quite user unfriendly
library. Not sure if he did buy his next card from NI though.

Rolf Kalbermatter

[astroboy]

Hi Thanks for your reply.
I am still working on it.
If it is still not solved,
either I will get it changed, or contact Advantech. maybe I will may ask my project engineer to consider the NI DAQs Card.

Regards,
Clement Yap

[astroboy]

I am still working on it.
If it is still not solved,
either I will get it changed, or contact Advantech. maybe I will may ask my project engineer to consider the NI DAQs Card.

Regards,
Clement Yap