05-29-2006 01:47 AM
Hi Daniel,
I have already found the web site you provided link for but I have some difficulties to execute the proposed solution. Could you prepare me a quick sample? In the attachment is the base vi.
Thanks
05-31-2006 09:46 AM
Hi AndrejK,
I apologize, but it's our general practice here in the Applications Engineering department not to develop code, the reason being that we have Alliance Partners that do that, and also because of bandwidth limitations. Perhaps someone else already has a synchronization example for the PXI 4472 and the 4220 already. Otherwise, I'd encourage you to look at the synchronization examples with E-Series devices to develop your program.
Thanks for your understanding,
Daniel L.
Applications Engineer
National Instruments
05-31-2006 12:32 PM
Hi David,
I have already done synchronization as stated in examples but with no success. The measured signals are not synchronized - the difference is around 20ms so I’m looking for help.
Thanks for the reply, Regards,
Andrej
06-01-2006 10:33 AM
06-01-2006 12:23 PM
Hi David,
thanks for the link, I believe that from this knowledge database we already received solution from Éva Porgánszki (Applications Engineer, National Instruments Hungary Kft.) Based on her solution we have done some testing today and there is still some delay between measured signals - see the attached *.vi and diagrams. The *vi is just the testing version so please don't be picky about the design because we quickly modified the base solution with the right acquisition signals. Let me explain what kind of sensors are attached to the cards. On 4472 accelerometer(s) and on the 4220 Full Wheatstone Bridge strain gauged force sensor.
We are now in the phase where we will check the sensors - especially for the force, because the mentioned delay could also be the property of the sensor.
We have started to use the NI-DAQmx because on NI site http://sine.ni.com/nips/cds/view/p/lang/en/nid/12317 is written that this card is designed to work with the NI-DAQmx drivers. And with the NI-DAQmx the configuration of the device is easier then with the traditional DAQ.
Regards, Andrej
06-01-2006 04:51 PM
06-01-2006 05:58 PM
Hi Andrej,
I just wanted to let you know that I was able to synchronize the two cards to roughly 300 microseconds. I tested this out by sending the same sine wave to both cards (using bare wires to the analog input of the 4472 and the differential sine signal to S+ and S- of the 4220). Therefore, I'd think that the 20ms differential that you are seeing is probably related to your sensors.
Please see the attached screenshots.
Regards,
Daniel L.
Applications Engineer
National Instruments
06-02-2006 01:26 AM