07-06-2011 09:50 AM
Does anyone have any experience in acquiring data from a serial connection with a WSN 3202 node?
We have
Ground
Power
Rx
Tx
pins - had thought the string data from the serial could be acquired through the digital inputs on the 3202, but haven't had any success.
We've powered the device externally (not through the sensor at all), but have so far been unable to get it working.
07-07-2011 10:45 AM
Hi bruce_tea,
You can read serial data through the digital input as it is still essentially a digital signal however you have to be able to translate this data to something meaningful. You can do this translation through LabVIEW code on the PC that is receiving the data. The translation process will consist of the handshaking and also converting the array to a string.
The following examples show you how you can do this in LabVIEW and using the DAQmx drivers. You will have to tweak it if you are using WSN however it gives you an idea of how it could be implemented:
https://decibel.ni.com/content/docs/DOC-12482
https://decibel.ni.com/content/docs/DOC-11436
https://decibel.ni.com/content/docs/DOC-6692
You also have to ensure that the baud rate of your serial data matches how fast you are reading this information. The digital inputs of the WSN 3202 use software timing.
I hope this helps,
Regards,
07-11-2011 04:12 AM
Hi there, thanks for the information - we're still having some trouble acquiring any sort of digital signal through the digital port. The digital port of the 3202 only appears to only record a 1/0 response at each measuring interval, which can't appear to match the Baud rate of the sensor (9600). I'm new to labview and may be making a simple error - any advice?
07-19-2011 09:29 AM
Hi Bobby_tea,
As I mentioned the rate of DIO acquisition with the 3202 is software timed which means it might not be able to read your data fast enough. You will need to increase the rate at which you read the data back in your LabVIEW code and decrease the baud rate.
If you send me your code I can have a look at it as well but I think the restriction is more on the hardware end.
Regards,