# USRP-1 and 4ch receiver? **URL:** \ **Category:** GNU Radio\ **Created:** [August 9, 2014, 9:18pm UTC](https://www.ruby-forum.com/t/usrp-1-and-4ch-receiver/231468 "2014-08-09T21:18:54Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\ **Post date:** [August 9, 2014, 9:18pm UTC](https://www.ruby-forum.com/t/usrp-1-and-4ch-receiver/231468/1 "2014-08-09T21:18:54Z")
Mr. Marcus Mueller, Thank you very much for suggestions. I have some more questions. 1. I searched for the GNU Radio mailing-list archive and found a discussion Subject: [Discuss-gnuradio] USRP1 4 Channel Subdev Issue Date: Tue, 19 Feb 2013 11:07:55 -0800 (PST) Then it would be possible to organize a 4-ch RX with USRP-1. (Some limitation is reported here, too.) But as you suggest, we can use only real (one) input for each frequency. Also I need to prepare the downward frequency conversion by our selves. Careful additional hardware design is necessary. I know this is not easy. 1. Your suggestion of “2 x B210” is very interesting. A good thing is that the frequency conversion is included in the board. But I want to know how to run 2 USRP boards from one application program. Is there an example? If possible I want to use GNU Radio Python code, but is this possible? If not, do we need to control from C++? In my application “phase coherency” across all inputs are necessary. “timing synchronization” is not necessary. 2. One more question. If 2) is possible, is it possible to run “2 x USRP-1” from a single application on a single PC? Regards, – Mamoru Y. / RISH, Kyoto University removed\_email\_address@domain.invalid Phone +81-774-38-3814, Cell +81-90-5653-7555 On 2014/08/08 1:00, removed\_email\_address@domain.invalid wrote:\> Message: 8 Date: Thu, 07 Aug 2014 09:41:38 +0200 From: Marcus M?ller ---
**Author:** ![Mamoru\_Y](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ecb155/32.png) [@Mamoru\_Y](https://www.ruby-forum.com/u/Mamoru_Y)\ **Post date:** [August 10, 2014, 4:59pm UTC](https://www.ruby-forum.com/t/usrp-1-and-4ch-receiver/231468/2 "2014-08-10T16:59:58Z")
Hey Mamoru, On 09.08.2014 21:17, Mamoru Y. via USRP-users wrote: > 1. Your suggestion of “2 x B210” is very interesting. A good thing is > that the frequency conversion is included in the board. But I want to > know how to run 2 USRP boards from one application program. Is there an > example? If possible I want to use GNU Radio Python code, but is this > possible? If not, do we need to control from C++? In my application > “phase coherency” across all inputs are necessary. “timing > synchronization” is not necessary. This is, in general, possible. For some devices (e.g. N210), you can spawn a USRP Source/Sink that will talk to several devices, and allocate channels accordingly (e.g., channel 0 → device 1, channel 2 → device 2 etc.). With B210, you simply create a USRP source for every device you have. If they are both connected to the same clock source, you have synchronized receivers. > 1. One more question. If 2) is possible, is it possible to run “2 x > USRP-1” from a single application on a single PC? You can also create two USRP Sources, one for each USRP1. However, unlike N210 or X310 for example, you can’t synch them through software. Use the “serial=XXX” or “name=XXX” device addrs to address these. M