11-02-2011 02:20 PM
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
11-03-2011 11:04 AM
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