Does it possible to run RF Record with the 5660?

[marspop]

hi,

I want to run the RF Record project with the 5660 RFSA device, but in ni.com recommended RF module is 5661. And all examples are for 5661. So, can I run this project with 5660? What's the main difference between 5660(5600+5620) and 5661(5600+5142)?

Thanks.

[RobertSzalapski]

I found this document which describes the differences between the PXI-5660 and PXI-5661.  It looks like streaming doesn't work as well for the 5660, but maybe someone else can clarify what hardware is needed for what bandwidth etc you need.

[AlexandreChen]

Hello marspop,

     To use 5660 with streaming, you can't run with examples for 5661, for the APIs of 5660 and 5661 are different.

     You should be able to do continouos acquisition with  "ni5660 fetch IQ data.vi" and then do disk streaming.

     You may reference to the discussion links to see if your application is feasible with 5660.

     http://forums.ni.com/ni/board/message?board.id=290&message.id=802&query.id=127683#M802

     http://forums.ni.com/ni/board/message?board.id=290&message.id=357&query.id=127683#M357

     Best regards,

     Alexander, NI Taiwan Engineer

[Chad B]

Marspop,

The main difference between the 5660 and 5661 is the amount of IF bandwidth that can be downconverted on the OSP of the digitizer. With the 5660, if you're trying to capture more than 1.25 MHz of bandwidth, that downconversion will have to happen in software. This takes quite a bit more CPU time, RAM, and PCI bus bandwidth, all of which can have an affect on the amount of data you can stream.

Regardless, the basic architecture of a streaming application is a producer-consumer loop, with the producer loop acquiring the data from NI-RFSA and the consumer loop writing it to a file. There's more info at http://www.ni.com/streaming/rf.htm . Your performance will be highly dependent on the horsepower of your system, and it would definitely be a lot better with a 5661. Good luck!

[Andy_Hinde]

Hello Marspop,

You can stream data to disk with the PXI-5660 only if the bandwidth you are streaming is <= 1.25 MHz.

If the PXI-5660 is configured for a bandwidth > 1.25 MHz, the PXI-5600 will sample at 64 MSamples/sec, generating binary IF data @ 128 MB/sec. This is too much data for the PCI bus to stream to disk, as PCI tops out at 133 MB /sec. 128 MB/sec is too close to the PCI limit.

The PXI-5660 OSP (onboard signal processor, in the form of a digital downconverter or DDC) turns on for the PXI-5660 with BW <= 1.25 MHz and the sampling rate drops to 2 MS/sec, generating binary IQ data @ 8 MB/sec. Smaller bandwidths will result in smaller sampling rates and data rates - see the PXI-5660 online help for more info. In any case, the PXI-5660 can be used to stream when this threshold is met.

The software for the PXI-5660 will be different, as the PXI-5661 is programmed with NI-RFSA driver VIs, and the PXI-5660 is programmed with the ni5660 VIs.The same architecture principles apply (i.e. producer/concumer arch in LabVIEW), but the configuration and streaming NI-RFSA VIs just need to be replaced with their ni5660 equivalents.

Regards,

Andy Hinde

National Instruments

Message Edited by Andy Hinde on 10-20-2008 02:37 AM