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Three RSP2, Three instances of SDRUno, One PC

Posted: Sat Jan 28, 2017 11:00 pm
by kc9nwp
Hi all,

Here's the short version:
I need to monitor three frequencies simultaneously. Each frequency is outside the 10MHz limit of a single RSP2. Can I, on one PC, run three RSP units and three instances of SDRUno?

Here's the bigger picture:
I need to route these frequencies into Radio Sky Pipe. I also need to keep power consumption as low as possible. I'd like each of the RSP/SDRUno instances to output via a virtual audio cable directly into Radio Sky Pipe. If this configuration will work, I can run the whole kit and caboodle on one PC. That's a big win for keeping power consumption low.

I've done some searching and I see some reports of more than one RSP working, but those anecdotes generally referenced extIO and different (non-SDRUno) software. I also see that the order the OS sees the RSPs will likely be an issue that will require some massaging. I can likely work around that.

Has anyone tried a configuration similar to this? I appreciate any input or insight the community may have.

Best,
Drew
KC9NWP

Re: Three RSP2, Three instances of SDRUno, One PC

Posted: Sun Jan 29, 2017 3:23 pm
by Tech_Support
Hello Drew,
Yes, in principle you can. However, you need to ensure that you have sufficient CPU processing power and memory and also it is critical that your USB host controller has sufficient USB end points available. Running at 10 MHz S/R, the RSP pushes high speed USB 2.0 close to the limit of what can be achieved and so you are likely to need three separate USB endpoints for three RSPs. Try to use the lowest sample rate that you can possible get away with.

Sincerely

SDRplay Tech_Support

Re: Three RSP2, Three instances of SDRUno, One PC

Posted: Sun Jan 29, 2017 4:08 pm
by kc9nwp
Thank you for the response. Very helpful.

I figure I can limit the sample rate and decimation in each instance of SDRUno to keep the bandwidth down and overhead low. Though even if I can fit the data through one bus/host controller, I'm unsure if I'll have enough power to drive the three devices. Should that be the case, I have powered hubs and powered pci expansion cards that should allow me to work around whatever throughput or power issues pop up.

CPU and memory consumption is a concern, but with your assurance that the second instance of SDRUno wont immediately throw an error, I believe that I can make this work.

Thanks again,
Drew