Can I sync a PCI6602 counter reading an encoder with a DAQ AI on a PCI E series card?

[Macl10]

I am trying to test accelerometers by using a centrifuge-type fixture that is run by a servo motor. I want to start the motor and DAQ(approx 20k-50k samples/sec) while simultaneously while reading the encoder. I basically want to timestamp each DUT measurement point related to the encoder position and time since started so I'll know the velocity of the fixture at each measurement point, including accel and decel of the fixture. Is this possible with the hardware I have? Is there an example of this, do I use RTSI? I couldn't find one. Thanks

[Spencer S.]

Greetings,

Yes, this should be possible with the combination of your PCI-6602 and your E-Series board. You will need to connect these devices with a RTSI cable. To synchronize your encoder measurements with your analog input measurements, you will need to route your analog input scan clock (SCANSTART) though RTSI to the gate of the counter that is performing the encoder measurement. With regards to the encoder, you will need to perform a buffered position measurement. Each scan clock pulse will load the current count into a buffer. You did not mention your programming environment, so I will assume you are using LabVIEW. I would suggest that you examine the following examples:

Two E-Series Shared ScanClk.vi
Measure Buffered Position (NI-TIO).vi

I realiz
e that you are not using two E-Series boards, but the first example demonstrates the proper procedure for exporting a scan clock through RTSI.

Good luck with your application.

Spencer S.

[Macl10]

Thanks,
I put together a VI from a couple of examples that does pretty much that, but doesn't quite work. I'll try to implement the scanclock vi. That should do it. Thanks again.