# RuntimeError: b200: 2 RX 1 TX and 1 RX 2 TX configurations not possible **URL:** \ **Category:** GNU Radio\ **Created:** [November 15, 2014, 3:33am UTC](https://www.ruby-forum.com/t/runtimeerror-b200-2-rx-1-tx-and-1-rx-2-tx-configurations-not-possible/233068 "2014-11-15T03:33:57Z")\ **Posts on this page:** 8\ **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:** [November 15, 2014, 3:33am UTC](https://www.ruby-forum.com/t/runtimeerror-b200-2-rx-1-tx-and-1-rx-2-tx-configurations-not-possible/233068/1 "2014-11-15T03:33:57Z")
Hello, I have a B210 and I am trying to transmit and receive from all it’s channels simultaneously. My setup is a macmini late 2012 with Ubuntu 12.04 install. I compiled and installed gnuradio from source using the gnuradio build script. I have developed the attached very simple GRC script that looks like this signal\_source@1khz --\> USRP\_sink\_channel1 signal\_source@2khz --\> USRP\_sink\_channel2 USRP\_source\_channel1 --\> WX\_GUI\_scope\_channel1 USRP\_source\_channel2 --\> WX\_GUI\_scope\_channel2 The problem I have is that I get the following message at random times and on average on 1/3 executions of the GRC script. linux; GNU C++ version 4.6.3; Boost\_104800; UHD\_003.008.000-18-g864f84b5 ## Using Volk machine: avx\_64\_mmx\_orc – Operating over USB 3. – Initialize CODEC control… – Initialize Radio control… – Performing register loopback test… pass – Performing register loopback test… pass – Performing CODEC loopback test… pass – Performing CODEC loopback test… pass – Asking for clock rate 32.000000 MHz – Actually got clock rate 32.000000 MHz – Performing timer loopback test… pass – Performing timer loopback test… pass – Asking for clock rate 28.000000 MHz – Actually got clock rate 28.000000 MHz – Performing timer loopback test… pass – Performing timer loopback test… pass – Tune Request: 915.000000 MHz – The RF LO does not support the requested frequency: – Requested LO Frequency: 915.000000 MHz – RF LO Result: 914.999999 MHz – Attempted to use the DSP to reach the requested frequency: – Desired DSP Frequency: -0.000001 MHz – DSP Result: -0.000001 MHz – Successfully tuned to 915.000000 MHz ## – Tune Request: 915.000000 MHz – The RF LO does not support the requested frequency: – Requested LO Frequency: 915.000000 MHz – RF LO Result: 914.999999 MHz – Attempted to use the DSP to reach the requested frequency: – Desired DSP Frequency: -0.000001 MHz – DSP Result: -0.000001 MHz – Successfully tuned to 915.000000 MHz ## – Asking for clock rate 28.000000 MHz – Actually got clock rate 28.000000 MHz – Performing timer loopback test… pass – Performing timer loopback test… pass – Tune Request: 915.000000 MHz – The RF LO does not support the requested frequency: – Requested LO Frequency: 915.000000 MHz – RF LO Result: 914.999999 MHz – Attempted to use the DSP to reach the requested frequency: – Desired DSP Frequency: 0.000001 MHz – DSP Result: 0.000001 MHz – Successfully tuned to 915.000000 MHz ## – Tune Request: 915.000000 MHz – The RF LO does not support the requested frequency: – Requested LO Frequency: 915.000000 MHz – RF LO Result: 914.999999 MHz – Attempted to use the DSP to reach the requested frequency: – Desired DSP Frequency: 0.000001 MHz – DSP Result: 0.000001 MHz – Successfully tuned to 915.000000 MHz _thread[thread-per-block[2]: \]: RuntimeError: b200: 2 RX 1 TX and 1 RX 2 TX configurations not possible_ It is obvious that I have all channels activated and that this message shouldn’t be appearing in the first place, let alone, appearing in a non-deterministic manner. Any ideas? Thank you in advance Lefteris ---
**Author:** ![Lefteris\_Kampianaki](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/4da419/32.png) [@Lefteris\_Kampianaki](https://www.ruby-forum.com/u/Lefteris_Kampianaki)\ **Post date:** [November 17, 2014, 11:16pm UTC](https://www.ruby-forum.com/t/runtimeerror-b200-2-rx-1-tx-and-1-rx-2-tx-configurations-not-possible/233068/2 "2014-11-17T23:16:42Z")
Hello, FYI I am having problems even with a simpler configuration like this: USRP\_source\_channel1 → USRP\_sink\_channel1 USRP\_source\_channel2 → USRP\_sink\_channel2 Does anyone face the same issue? It is really frustrating because 1/3 executions are wasted and this causes problems with later design, that has to have an execution rate of \> 1Hz Thank you in advance Lefteris On Fri, Nov 14, 2014 at 6:32 PM, Lefteris Kampianakis \< [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)\> wrote: > ## – Initialize CODEC control… – Actually got clock rate 28.000000 MHz > > ## – Actually got clock rate 28.000000 MHz > > b200: 2 RX 1 TX and 1 RX 2 TX configurations not possible\* – Eleftherios(Lefteris) Kampianakis Electronics and Computer Engineer PHD Candidate and Researcher at Sensing Computing Communications Group (SGCC) Department of Electrical Engineering University of Washington 3927 Adams Lane, NE, Mercer Court D805B, 98105 website: [http://staff.washington.edu/ekampian/](http://staff.washington.edu/ekampian/) [http://users.isc.tuc.gr/~ekabianakis/](http://users.isc.tuc.gr/~ekabianakis/) mail: [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![Lefteris\_Kampianaki](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/4da419/32.png) [@Lefteris\_Kampianaki](https://www.ruby-forum.com/u/Lefteris_Kampianaki)\ **Post date:** [November 17, 2014, 11:30pm UTC](https://www.ruby-forum.com/t/runtimeerror-b200-2-rx-1-tx-and-1-rx-2-tx-configurations-not-possible/233068/3 "2014-11-17T23:30:01Z")
On 11/17/2014 05:15 PM, Lefteris Kampianakis wrote: > has to have an execution rate of \> 1Hz > \<[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) [mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)\> wrote: > signal\_source@2khz → USRP\_sink\_channel2 > Using Volk machine: avx\_64\_mmx\_orc > – Performing timer loopback test… pass > – DSP Result: -0.000001 MHz > – > – DSP Result: 0.000001 MHz > – > > (SGCC) > [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio) > We shall probably need a more-detailed description of what you’re > doing. Like the actual .grc files, etc. From your description, I think you’re wanting to: bring up flow-graph, exchange a very small number of samples, and then exit the flow-graph, and do this in a loop? That seems horribly inefficient, quit distinct from it perhaps uncovering possible bugs in the latest UHD. But providing more information will help those who can help you. ---
**Author:** ![Lefteris\_Kampianaki](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/4da419/32.png) [@Lefteris\_Kampianaki](https://www.ruby-forum.com/u/Lefteris_Kampianaki)\ **Post date:** [November 18, 2014, 2:48am UTC](https://www.ruby-forum.com/t/runtimeerror-b200-2-rx-1-tx-and-1-rx-2-tx-configurations-not-possible/233068/4 "2014-11-18T02:48:05Z")
Hi all, I think what Lefteris tries to implement is a 2x2 loopback with a USRP-B210. At least this is what I can see from the flowgraph attached in the first email. Is that possible with B210? Best, George ---
**Author:** ![Lefteris\_Kampianaki](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/4da419/32.png) [@Lefteris\_Kampianaki](https://www.ruby-forum.com/u/Lefteris_Kampianaki)\ **Post date:** [November 17, 2014, 11:48pm UTC](https://www.ruby-forum.com/t/runtimeerror-b200-2-rx-1-tx-and-1-rx-2-tx-configurations-not-possible/233068/5 "2014-11-17T23:48:44Z")
Hi Lefteris - We recently added that warning. We think we got it right, but it’s possible something is wrong with the logic that makes it fire. Can you share your GRC flowgraph? Cheers, Ben ---
**Author:** ![Lefteris\_Kampianaki](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/4da419/32.png) [@Lefteris\_Kampianaki](https://www.ruby-forum.com/u/Lefteris_Kampianaki)\ **Post date:** [November 18, 2014, 2:53am UTC](https://www.ruby-forum.com/t/runtimeerror-b200-2-rx-1-tx-and-1-rx-2-tx-configurations-not-possible/233068/6 "2014-11-18T02:53:31Z")
On 11/17/2014 08:46 PM, George S. wrote: > George > Yes, that should easily be possible. But some checking code was added in UHD 3.8.0 which apparently gets inappropriately triggered sometimes, which is what is causing this issue. There was also talk about running and executing the entire flow-graph at a cadence of faster than 1Hz, which suggested some design issues in the intended application not related to the bug in UHD. ---
**Author:** ![Lefteris\_Kampianaki](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/4da419/32.png) [@Lefteris\_Kampianaki](https://www.ruby-forum.com/u/Lefteris_Kampianaki)\ **Post date:** [November 19, 2014, 3:38am UTC](https://www.ruby-forum.com/t/runtimeerror-b200-2-rx-1-tx-and-1-rx-2-tx-configurations-not-possible/233068/7 "2014-11-19T03:38:17Z")
Hello again, It seems that the patch fixed the problem! Thanks Julian! For installing the patch with build-gnuradio script: 1. download patch 2. open a terminal at the folder where your uhd files are saved. By default this is in the folder uhd, inside the folder where you executed ./build-gnuradio 3. follow instructions here: [How to create and apply a patch with Git | devroom.io](https://ariejan.net/2009/10/26/how-to-create-and-apply-a-patch-with-git/) or if you are lazy execute: git am --signoff \< patch\_file\_name 4. execute ./build-gnuradio uhd\_build to rebuild all UHD 5. done I still have issues that are described here [http://lists.ettus.com/pipermail/usrp-users\_lists.ettus.com/2014-November/011247.html](http://lists.ettus.com/pipermail/usrp-users_lists.ettus.com/2014-November/011247.html) But this is for another thread. Nonetheless, any suggestions for improving my setup are welcome. Thank you Lefteris On Tue, Nov 18, 2014 at 2:27 PM, Lefteris Kampianakis \< [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)\> wrote: > 1. Produce samples using MATLAB, not python, not C++. Application > ) > the data through sockets. > [http://www.ettus.com/content/files/kb/mimo\_and\_sync\_with\_usrp\_updated.pdf](http://www.ettus.com/content/files/kb/mimo_and_sync_with_usrp_updated.pdf) > > The code attached achieves a refresh rate of 0.5Hz when not receiving the [http://lists.ettus.com/pipermail/usrp-users\_lists.ettus.com/2014-November/011247.html](http://lists.ettus.com/pipermail/usrp-users_lists.ettus.com/2014-November/011247.html) > Byte Order: Little Endian > CPU MHz: 1200.000 > Oct 29 09:56:49 UTC 2014 x86\_64 x86\_64 x86\_64 GNU/Linux > Device Address: > > > FYI I am having problems even with a simpler configuration like this: > > Lefteris > > > > > USRP\_source\_channel2 → WX\_GUI\_scope\_channel2 > > > – Performing register loopback test… pass > > > – Performing timer loopback test… pass > > > – The RF LO does not support the requested frequency: > > > – Performing timer loopback test… pass > > > – The RF LO does not support the requested frequency: > > > > [http://users.isc.tuc.gr/~ekabianakis/](http://users.isc.tuc.gr/~ekabianakis/) > > Department of Electrical Engineering > > University of Washington > > 3927 Adams Lane, NE, Mercer Court D805B, 98105 > > website: [http://staff.washington.edu/ekampian/](http://staff.washington.edu/ekampian/) > > [http://users.isc.tuc.gr/~ekabianakis/](http://users.isc.tuc.gr/~ekabianakis/) > > mail: [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) – Eleftherios(Lefteris) Kampianakis Electronics and Computer Engineer PHD Candidate and Researcher at Sensing Computing Communications Group (SGCC) Department of Electrical Engineering University of Washington 3927 Adams Lane, NE, Mercer Court D805B, 98105 website: [http://staff.washington.edu/ekampian/](http://staff.washington.edu/ekampian/) [http://users.isc.tuc.gr/~ekabianakis/](http://users.isc.tuc.gr/~ekabianakis/) mail: [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![Lefteris\_Kampianaki](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/4da419/32.png) [@Lefteris\_Kampianaki](https://www.ruby-forum.com/u/Lefteris_Kampianaki)\ **Post date:** [November 18, 2014, 11:30pm UTC](https://www.ruby-forum.com/t/runtimeerror-b200-2-rx-1-tx-and-1-rx-2-tx-configurations-not-possible/233068/8 "2014-11-18T23:30:02Z")
Hello all and thank you for your replies. Sorry for my delayed answer First of, I am completely new to USRP, gnuradio and uhd so excuse my inability to address the issue myself and point out possible reasons for the error. The overview of what I want to do is this: while(1){ 1. Produce samples using MATLAB, not python, not C++. Application specific, cann’t change that. 2. Write the samples to a vector/file. 3. Transfer the data to the corresponding gnuradio program written in python. This can be done using either files or TCP sockets 4. The samples must be transmitted from one of B210’s channels (the other is 50Ohms terminated) while the two RX channels sample at the same time. That is, the transmission and reception must be executed at the same time. 5. Measure and compensate the phase between TX and RX which changes in every session. (see here: [http://lists.ettus.com/pipermail/usrp-users\_lists.ettus.com/2014-October/011140.html](http://lists.ettus.com/pipermail/usrp-users_lists.ettus.com/2014-October/011140.html) ) 6. Stop the gnuradio script in a way that a) no more samples are written to memory/disk b) restart is posssible without errors. For details see here: [http://lists.ettus.com/pipermail/usrp-users\_lists.ettus.com/2014-October/011242.html](http://lists.ettus.com/pipermail/usrp-users_lists.ettus.com/2014-October/011242.html) and here [GNURADIO and USRP: Start(), Stop(), run(), wait() in GNURADIO : top\_block](http://sumitgnuradio.blogspot.com/2012/10/either-you-can-use-tb.html) and here [[Discuss-gnuradio] how to stop the top\_block and restart signal transmis](http://lists.gnu.org/archive/html/discuss-gnuradio/2011-02/msg00300.html) 7)Process samples in MATLAB by ‘freading’ the written files or by getting the data through sockets. } My goal is to conduct channel measurements. Therefore, in order to compensate for the TX/RX phase that changes in every session in B210 I have splitted the signal using a power splitter with known phase and send one port to RX1. Since RX1, RX2 phase is constant in every session, I can then calculate the phase difference between TX and RX and do my channel measurements. In other words, I want to implement a setup like the one depicted here [http://www.ettus.com/content/files/kb/mimo\_and\_sync\_with\_usrp\_updated.pdf](http://www.ettus.com/content/files/kb/mimo_and_sync_with_usrp_updated.pdf) in figure 1 in order to acquire knowledge of the phase between the RF inputs and outputs of the B210. Now, as to what I have developed so far. I have attached a grc flowgraph that is as simple as it gets. It consists of 2 signal sources and a scope connected to a usrp sink and source respectively. This setup produces the aforementioned error. I also noticed that whenever I receive this error, either only TX works or only RX, never both and this is done randonly. An example of series of executions that I monitored is the following: OK (both transmitting) OK (both transmitting) Error, Only RX works OK (both transmitting) OK (both transmitting) OK (both transmitting) Error, Only RX works Error, Only TX works OK (both transmitting) Error, Only TX works and it continues randomly That was a first indication that something is wrong in the first place. I proceeded with the development of a simple flowgraph that utilizes file sinks and sources as well as head blocks to stop the execution of the flowgraph after a specifica mount of samples. This is attached too. Finally, I edited the python code, so that endless loop of flowgraphs restarting is conducted. (also attached). The code attached achieves a refresh rate of 0.5Hz when not receiving the error, which is acceptable for my application. I know this is completely inefficient and please share any ideas on the subject. However, this is not my primary concern at this point. My main objective now is to have a viable demonstration and not a fast refresh rate. 0.5 Hz is barely enough. At this point my 2 major issues are the following: 1. The error/warning that this thread discusses 2. The problem described here: [http://lists.ettus.com/pipermail/usrp-users\_lists.ettus.com/2014-November/011247.html](http://lists.ettus.com/pipermail/usrp-users_lists.ettus.com/2014-November/011247.html) which is being addressed. Any advice on any subject from the ones mentioned here are extremely welcome. My setup is the following lscpu: Architecture: x86\_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 4 On-line CPU(s) list: 0-3 Thread(s) per core: 2 Core(s) per socket: 2 Socket(s): 1 NUMA node(s): 1 Vendor ID: GenuineIntel CPU family: 6 Model: 58 Stepping: 9 CPU MHz: 1200.000 BogoMIPS: 4988.84 Virtualization: VT-x L1d cache: 32K L1i cache: 32K L2 cache: 256K L3 cache: 3072K NUMA node0 CPU(s): 0-3 uname -a: Linux kampianakis-Macmini 3.13.0-39-generic #66~precise1-Ubuntu SMP Wed Oct 29 09:56:49 UTC 2014 x86\_64 x86\_64 x86\_64 GNU/Linux lshw output, attached. Gnuradio version 3.7.5.1 ## uhd\_find\_devices: linux; GNU C++ version 4.6.3; Boost\_104800; UHD\_003.008.000-18-g864f84b5 ## – UHD Device 0 Device Address: type: b200 name: serial: F50007 product: B210 Thank you in advance Lefteris PS sorry for the long post. On Mon, Nov 17, 2014 at 2:15 PM, Lefteris Kampianakis \< [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)\> wrote: > to have an execution rate of \> 1Hz > [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)\> wrote: > > > signal\_source@2khz → USRP\_sink\_channel2 > > – Operating over USB 3. > > – Asking for clock rate 28.000000 MHz > > – Successfully tuned to 915.000000 MHz > > – Asking for clock rate 28.000000 MHz > > – Successfully tuned to 915.000000 MHz > > \*thread[thread-per-block[2]: \]: > > Lefteris > > University of Washington > > 3927 Adams Lane, NE, Mercer Court D805B, 98105 > > website: [http://staff.washington.edu/ekampian/](http://staff.washington.edu/ekampian/) > > [http://users.isc.tuc.gr/~ekabianakis/](http://users.isc.tuc.gr/~ekabianakis/) > > mail: [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) – Eleftherios(Lefteris) Kampianakis Electronics and Computer Engineer PHD Candidate and Researcher at Sensing Computing Communications Group (SGCC) Department of Electrical Engineering University of Washington 3927 Adams Lane, NE, Mercer Court D805B, 98105 website: [http://staff.washington.edu/ekampian/](http://staff.washington.edu/ekampian/) [http://users.isc.tuc.gr/~ekabianakis/](http://users.isc.tuc.gr/~ekabianakis/) mail: [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)