Real-Time Measurement and Control

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DMA Transfer Rate

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Does anyone know what the transfer rate of a DMA FIFO is on a cRIO-9024 (800mHz) controller?

 

 

I'm attempting to do something similar to Christian Leow's example here:

http://forums.ni.com/t5/Real-Time-Measurement-and/CRIO-Save-to-Memory/m-p/815285?requireLogin=False

 

In my scenario I need to:

1) Acquire N channels at 100Ks/s via the NI-9215

2) Hold this in RT memory until the PC Host requests for a time slice of data (~5 seconds)

3) I do not need to write any high speed data to disk.

 

I'm trying to figure out if this is possible and if so how many channels can i acquire.

 

Thanks,

Craig

 

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So the limiting factor in this scenario is the length of time and the number of possible channels.  The data is transferred across a PCI bus which can transfer 133MB/s.  If you filled an entire 8 slot chassis with 9215 modules you would use about 12 MB/s.  With 4GB of memory on the 9024 you will be fine.  The limit is thus 32 Channels only because the chassis would be full.

 

Jacob K

Jacob K
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