Acquring Data at particular frequency in CompactRIO

[javs24_1]

Hi


I have a cRIO-9014 with four slot configuarable chassis.My application has a set of 16 digital/TTL data inputs including one clock signal.I would like to acquire the inputs at this clock frequency (150 Khz).I have a NI-9403 digital I/O module.I would like to know if it is possible to acquire data with this module or i will have to go for another Digital I/O module.If i have to go for another IO module , then which one.

Thanks

Javed

[Christian_L]

The 9403, like all other DIO C series modules, does not have a specific trigger or scan clock input that will automatically sample the other DIO lines at a rate specified by an external signal. You can however implement this functionality using the DIO you have and the FPGA. In fact this is the purpose of the Reconfigurable I/O (RIO) architecture. With some basic I/O channels and the configurable hardware of the FPGA, you can define you own custom hardware including triggers, scan clocks, counters, etc.

For your application, sample all of the input lines of interest at the highest rate possible. In the FPGA code monitor your clock line and look for rising (or falling edges). When you see an edge on your clock signal then and only then log all of the data from the other lines into a FIFO or register for processing or to pass back to the host application.

Here's a simple example using a few channels from a 9401 (same as the 9403 but with fewer channels).

Message Edited by Christian L on 06-24-2008 09:58 AM

[javs24_1]

Thanks a lot Christian


I am new to CompactRio hence cannot fully appreciate the features of it.I will try your logic and I think it will suffice for my application.

Will get back in case of any problem.

Thanks once again.


Javed

[sharda]

Hi,

Can you please give some insight on aquiring frequency data using 9403??

Thanks

Ajay

[Christian_L]

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sharda wrote:

Hi,

Can you please give some insight on aquiring frequency data using 9403??

Thanks

Ajay

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Can you please be a bit more specific about what it is you would like to do. Also if you have a new questions it is best to start a new topic in the discussion forum, rather than attaching your question to an old thread.

Have you looked in the CompactRIO specific examples installed with NI-RIO?

C:\Program Files\National Instruments\LabVIEW 8.6\examples\CompactRIO

[TurboTurtle]

hopefully your query has been solved, Javed

Vishal 

Applications Engineer

National Instruments

India