On 2021-10-11 8:24 a.m., Thangaraj Mukara Dhakshinamoorthy wrote:

Performance within a VM is often very poor.  If you replace the output
file with "/dev/null", ,does this change the behavior?

That would be a question for the discuss-gnuradio mailing list.

What gain setting did you use?  What kind of antenna on the antenna port?

Hello Marcus,

My system config (changed my working environment):
OS: Ubuntu 20.04.3 LTS
OS Type: 64-bit
RAM: 3.8 GB
Processor: Intel Core i5-2450M CPU @2.50GHz x4
UHD version: 3.15.0.0
GNU Radio version: 3.8.1.0
SDR Device: Ettus USRP N320
My Goal: Use Ettus N320 as Analysis tool (Ex: Spectrum Analyzer)

1. Performance within a VM is often very poor.  If you replace the output file with "/dev/null", ,does this change the behavior?

komro@komro-HP-ProBook-6560b:/usr/lib/uhd/examples$ ./rx_samples_to_file --freq 98e6 --rate 5e6 --gain 20 --duration 10  /dev/null

Creating the usrp device with: ...
[INFO] [UHD] linux; GNU C++ version 9.2.1 20200304; Boost_107100; UHD_3.15.0.0-2build5
[INFO] [MPMD] Initializing 1 device(s) in parallel with args: mgmt_addr=192.168.10.2,type=n3xx,product=n320,serial=31F43B7,claimed=False,addr=192.168.10.2
[WARNING] [MPM.RPCServer] A timeout event occured!
[WARNING] [MPM.RPCServer] Attempt to read logs without valid claim from 192.168.10.1
.
.
.

Setting RX Rate: 5.000000 Msps...
[WARNING] [RFNOC] The requested decimation is odd; the user should expect passband CIC rolloff.
Select an even decimation to ensure that a halfband filter is enabled.
Decimations factorable by 4 will enable 2 halfbands, those factorable by 8 will enable 3 halfbands.
decimation = dsp_rate/samp_rate -> 49 = (245.760000 MHz)/(5.000000 MHz)

Actual RX Rate: 5.015510 Msps...

Setting RX Freq: 98.000000 MHz...
Setting RX LO Offset: 0.000000 MHz...
[WARNING] [MULTI_USRP] The hardware does not support the requested RX sample rate:
Target sample rate: 5.000000 MSps
Actual sample rate: 5.015510 MSps

Actual RX Freq: 98.000000 MHz...

Setting RX Gain: 20.000000 dB...
Actual RX Gain: 20.000000 dB...

Waiting for "lo_locked": ++++++++++ locked.

Press Ctrl + C to stop streaming...
DGot an overflow indication. Please consider the following:
Your write medium must sustain a rate of 20.062041MB/s.
Dropped samples will not be written to the file.
Please modify this example for your purposes.
This message will not appear again.
D
Done!

2. What gain settings did you use?

[cid:image001.png@01D7BF5E.C56E4C10]

[cid:image003.png@01D7BF5E.C56E4C10]

3. What kind of antenna on the antenna port?
   Antenna Techincal Information
   Manufacturer                RF Solutions
   PART                            ANT-8WHIP3H-SMA
   TYPE                            90DEG HINGED WHIP
   FREQUENCY                  868MHz
   CONNECTOR                  SMA
   FORM                          HINGED WHIP
   DB GAIN                      +3dBi
   OP TEMPERATURE        -40 to +70oC

4. Now when I ran the above spectrum analyzer flowgraph, I receive the runtime error as shown below:
   <<< Welcome to GNU Radio Companion 3.8.1.0 >>>

Block paths:
/usr/share/gnuradio/grc/blocks

Loading: "/home/komro/usrp_spectrum_analyzer.grc"

Generating: '/home/komro/usrp_spectrum_analyzer.py'

Executing: /usr/bin/python3 -u /home/komro/usrp_spectrum_analyzer.py

Warning: failed to XInitThreads()
[INFO] [UHD] linux; GNU C++ version 9.2.1 20200304; Boost_107100; UHD_3.15.0.0-2build5
[INFO] [MPMD] Initializing 1 device(s) in parallel with args: mgmt_addr=192.168.10.2,type=n3xx,product=n320,serial=31F43B7,claimed=False,addr=192.168.10.2
[INFO] [MPM.PeriphManager] init() called with device args clock_source=internal,time_source=internal,product=n320,mgmt_addr=192.168.10.2'. [INFO] [MPM.Rhodium-0] init() called with args clock_source=internal,time_source=internal,product=n320,mgmt_addr=192.168.10.2'
[INFO] [MPM.Rhodium-1] init() called with args `clock_source=internal,time_source=internal,product=n320,mgmt_addr=192.168.10.2'
[INFO] [0/Replay_0] Initializing block control (NOC ID: 0x4E91A00000000004)
[ERROR] [UHD] Exception caught in safe-call.
in ctrl_iface_impl<_endianness>::~ctrl_iface_impl() [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:50
this->send_cmd_pkt(0, 0, true); -> EnvironmentError: IOError: Block ctrl (CE_01_Port_40) no response packet - AssertionError: bool(buff)
in uint64_t ctrl_iface_impl<_endianness>::wait_for_ack(bool, double) [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG; uint64_t = long unsigned int]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:151

[ERROR] [MPMD] Failure during block enumeration: EnvironmentError: IOError: Block ctrl (CE_01_Port_40) no response packet - AssertionError: bool(buff)
in uint64_t ctrl_iface_impl<_endianness>::wait_for_ack(bool, double) [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG; uint64_t = long unsigned int]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:151

Traceback (most recent call last):
File "/home/komro/usrp_spectrum_analyzer.py", line 192, in <module>
main()
File "/home/komro/usrp_spectrum_analyzer.py", line 170, in main
tb = top_block_cls()
File "/home/komro/usrp_spectrum_analyzer.py", line 91, in init
self.uhd_usrp_source_0 = uhd.usrp_source(
File "/usr/lib/python3/dist-packages/gnuradio/uhd/init.py", line 125, in constructor_interceptor
return old_constructor(*args)
File "/usr/lib/python3/dist-packages/gnuradio/uhd/uhd_swig.py", line 2787, in make
return _uhd_swig.usrp_source_make(device_addr, stream_args, issue_stream_cmd_on_start)
RuntimeError: RuntimeError: Failed to run enumerate_rfnoc_blocks()

What is the problem here?

PS: I can still ping the USRP device successfully!

Looking forward to your kind response.

Regards,
Thangz
Von: Marcus D. Leech patchvonbraun@gmail.com
Gesendet: Montag, 11. Oktober 2021 18:08
An: Thangaraj Mukara Dhakshinamoorthy thangaraj@komro.net; usrp-users@lists.ettus.com
Betreff: Re: UHD example rx_samples_to_file fails

On 2021-10-11 8:24 a.m., Thangaraj Mukara Dhakshinamoorthy wrote:
Hello Everyone,

My system config:
Host OS: Windows 10
Guest OS: VirtualBox Ubuntu 20.04.3 LTS
UHD version: 3.15.0.0
GNU Radio version: 3.8.1.0
SDR Device : Ettus USRP N320
My Goal: Use Ettus N320 as Analysis tool (Ex: Spectrum Analyzer)

Console logs:

komro@komro-HP-ProBook-6560b:/usr/lib/uhd/examples$ ./rx_samples_to_file --freq 98e6 --rate 5e6 --gain 20 --duration 10 usrp_samples.dat

Creating the usrp device with: ...
[INFO] [UHD] linux; GNU C++ version 9.2.1 20200304; Boost_107100; UHD_3.15.0.0-2build5
[INFO] [MPMD] Initializing 1 device(s) in parallel with args: mgmt_addr=192.168.10.2,type=n3xx,product=n320,serial=31F43B7,claimed=False,addr=192.168.10.2
[INFO] [MPM.PeriphManager] init() called with device args mgmt_addr=192.168.10.2,time_source=internal,clock_source=internal,product=n320'. [INFO] [MPM.Rhodium-0] init() called with args mgmt_addr=192.168.10.2,time_source=internal,clock_source=internal,product=n320'
[INFO] [MPM.Rhodium-1] init() called with args `mgmt_addr=192.168.10.2,time_source=internal,clock_source=internal,product=n320'
.
.
.
.
[WARNING] [MULTI_USRP] The hardware does not support the requested RX sample rate:
Target sample rate: 5.000000 MSps
Actual sample rate: 5.015510 MSps
Actual RX Rate: 5.015510 Msps...

Setting RX Freq: 98.000000 MHz...
Setting RX LO Offset: 0.000000 MHz...
Actual RX Freq: 98.000000 MHz...

Setting RX Gain: 20.000000 dB...
Actual RX Gain: 20.000000 dB...

Waiting for "lo_locked": ++++++++++ locked.

Press Ctrl + C to stop streaming...
DGot an overflow indication. Please consider the following:
Your write medium must sustain a rate of 20.062041MB/s.
Dropped samples will not be written to the file.
Please modify this example for your purposes.
This message will not appear again.
DDDD
Done!

[ERROR] [UHD] Exception caught in safe-call.
in ctrl_iface_impl<_endianness>::~ctrl_iface_impl() [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:50
this->send_cmd_pkt(0, 0, true); -> EnvironmentError: IOError: Block ctrl (CE_00_Port_33) no response packet - AssertionError: bool(buff)
in uint64_t ctrl_iface_impl<_endianness>::wait_for_ack(bool, double) [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG; uint64_t = long unsigned int]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:151

[ERROR] [UHD] Exception caught in safe-call.
in ctrl_iface_impl<_endianness>::~ctrl_iface_impl() [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:50
this->send_cmd_pkt(0, 0, true); -> EnvironmentError: IOError: Block ctrl (CE_00_Port_30) packet parse error - EnvironmentError: IOError: Expected packet index: 28 Received index: 29
[ERROR] [UHD] Exception caught in safe-call.
in ctrl_iface_impl<_endianness>::~ctrl_iface_impl() [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:50
this->send_cmd_pkt(0, 0, true); -> EnvironmentError: IOError: Block ctrl (CE_01_Port_40) packet parse error - EnvironmentError: IOError: Expected packet index: 566 Received index: 567
Performance within a VM is often very poor.  If you replace the output file with "/dev/null", ,does this change the behavior?

1. What should I do in order to fix this?

2. I tried the fm_receiver flowgraph in GNU Radio, it was running successfully but when I tune the frequency there is nothing I could hear except the first 5 seconds noise!
   That would be a question for the discuss-gnuradio mailing list.

3. I also tried the example 'Spectrum Analyzer' grc program, it was also running without error but there was not much changes/effects when I tune the frequency! Is there something wrong in receiver?
   What gain setting did you use?  What kind of antenna on the antenna port?

Thank you in advance!

Regards,
Thangz

On 2021-10-12 5:46 a.m., Thangaraj Mukara Dhakshinamoorthy wrote:

So, this looks increasingly like your network interface is dropping
frames.  TO confirm--this is still under a VM, or on
  actual hardware?

What type of Ethernet interface are you using--USB-to-Ethernet devices
are known to not work very well because they cannot
 sustain high rates, and often reorder frames on the wire.   What
kind of cabling are you using?  Have you tried replacing that
  cabling?

Also, I'll note that the default master_clock_rate on the N320 is
245.76MHz, which means that your requested 5.0Msps
  sample rate cannot be precisely supported.  You can specify
"master_clock_rate=200e6" in the device arguments to
  request that as a master clock rate, which will allow a 5Msps sample
rate.

Also, the gain range on N320 goes up to 75dB, which means unless you
have a VERY strong signal, a gain setting of
 20dB will likely produce noisy/non-existent results.

The fact that you got "no response packet" again indicates a
network-layer issue.

Also, I'll note that an antenna designed for 800MHz to 1GHz will be
next-to-useless for the FM
  band.

Also, there's a simple spectrum analyser application, uhd_fft, that
comes with the Gnu Radio installation
  on Ubuntu.

Hello Marcus,

1.  So, this looks increasingly like your *network* interface is dropping frames.  TO confirm--this is still under a VM, or on
   

actual hardware?
Yes, it is a seperate laptop which runs only ubuntu as main OS.
What type of Ethernet interface are you using--USB-to-Ethernet devices are known to not work very well because they cannot
sustain high rates, and often reorder frames on the wire.  What kind of cabling are you using?  Have you tried replacing that
cabling?

Now I removed the USB to Ethernet adapter and connected the ethernet cable (CAT5E 350MHz cable) directly into laptop!

Also, I'll note that the default master_clock_rate on the N320 is 245.76MHz, which means that your requested 5.0Msps
sample rate cannot be precisely supported.  You can specify "master_clock_rate=200e6" in the device arguments to
request that as a master clock rate, which will allow a 5Msps sample rate.
Done!
Also, the gain range on N320 goes up to 75dB, which means unless you have a VERY strong signal, a gain setting of
20dB will likely produce noisy/non-existent results.
There is strong signal in 868MHz frequency, but still there is no capture file created by the UHD example program!

Console logs:
komro@komro-HP-ProBook-6560b:/usr/lib/uhd/examples$ ./rx_samples_to_file --args="master_clock_rate=200e6" --freq 868e6 --rate 5e6 --gain 20 --duration 10 usrp_samples.dat

Creating the usrp device with: master_clock_rate=200e6...
[INFO] [UHD] linux; GNU C++ version 9.2.1 20200304; Boost_107100; UHD_3.15.0.0-2build5
[INFO] [MPMD] Initializing 1 device(s) in parallel with args: mgmt_addr=192.168.178.61,type=n3xx,product=n320,serial=31F43B7,claimed=False,addr=192.168.10.2,master_clock_rate=200e6
[WARNING] [MPM.RPCServer] A timeout event occured!
[INFO] [MPM.PeriphManager] init() called with device args product=n320,mgmt_addr=192.168.178.61,clock_source=internal,time_source=internal,master_clock_rate=200e6'. [INFO] [MPM.Rhodium-0] init() called with args product=n320,mgmt_addr=192.168.178.61,clock_source=internal,time_source=internal,master_clock_rate=200e6'
[INFO] [MPM.Rhodium-1] init() called with args `product=n320,mgmt_addr=192.168.178.61,clock_source=internal,time_source=internal,master_clock_rate=200e6'
.
.
.
Setting RX Rate: 5.000000 Msps...
Actual RX Rate: 5.000000 Msps...

Setting RX Freq: 868.000000 MHz...
Setting RX LO Offset: 0.000000 MHz...
Actual RX Freq: 868.000000 MHz...

Setting RX Gain: 20.000000 dB...
Actual RX Gain: 20.000000 dB...

Waiting for "lo_locked": ++++++++++ locked.

Press Ctrl + C to stop streaming...

Done!
(but no file created)

2. Regarding the Spectrum Analyzer Program, I reduced the sample rate to 2MHz, then it worked perfectly and the fluctuations in the graph were seen clearly without any stop! I also check the uhd_fft program which worked perfectly too!

3. Regarding the FM receiver flowgraph,I tried tuning various FM channel frequencies (88-108 MHz) and gains, but there is no effect other than the noisy sound (always). What should I do to build a FM receiver application using N320 and which antenna should I use (please suggest for multipurpose too)?

   [cid:image005.png@01D7C058.9FC3BFE0]

PS: I followed the gnuradio tutorial on usrp fm receiver

Looking forward to your kind response :)

Regards,
Thangaraj

Von: Marcus D. Leech patchvonbraun@gmail.com
Gesendet: Dienstag, 12. Oktober 2021 17:03
An: Thangaraj Mukara Dhakshinamoorthy thangaraj@komro.net; usrp-users@lists.ettus.com
Betreff: Re: AW: UHD example rx_samples_to_file fails

On 2021-10-12 5:46 a.m., Thangaraj Mukara Dhakshinamoorthy wrote:
Hello Marcus,

My system config (changed my working environment):
OS: Ubuntu 20.04.3 LTS
OS Type: 64-bit
RAM: 3.8 GB
Processor: Intel Core i5-2450M CPU @2.50GHz x4
UHD version: 3.15.0.0
GNU Radio version: 3.8.1.0
SDR Device: Ettus USRP N320
My Goal: Use Ettus N320 as Analysis tool (Ex: Spectrum Analyzer)

1.   Performance within a VM is often very poor.  If you replace the output file with "/dev/null", ,does this change the behavior?
   

komro@komro-HP-ProBook-6560b:/usr/lib/uhd/examples$ ./rx_samples_to_file --freq 98e6 --rate 5e6 --gain 20 --duration 10  /dev/null

Creating the usrp device with: ...
[INFO] [UHD] linux; GNU C++ version 9.2.1 20200304; Boost_107100; UHD_3.15.0.0-2build5
[INFO] [MPMD] Initializing 1 device(s) in parallel with args: mgmt_addr=192.168.10.2,type=n3xx,product=n320,serial=31F43B7,claimed=False,addr=192.168.10.2
[WARNING] [MPM.RPCServer] A timeout event occured!
[WARNING] [MPM.RPCServer] Attempt to read logs without valid claim from 192.168.10.1
.
.
.

Setting RX Rate: 5.000000 Msps...
[WARNING] [RFNOC] The requested decimation is odd; the user should expect passband CIC rolloff.
Select an even decimation to ensure that a halfband filter is enabled.
Decimations factorable by 4 will enable 2 halfbands, those factorable by 8 will enable 3 halfbands.
decimation = dsp_rate/samp_rate -> 49 = (245.760000 MHz)/(5.000000 MHz)

Actual RX Rate: 5.015510 Msps...

Setting RX Freq: 98.000000 MHz...
Setting RX LO Offset: 0.000000 MHz...
[WARNING] [MULTI_USRP] The hardware does not support the requested RX sample rate:
Target sample rate: 5.000000 MSps
Actual sample rate: 5.015510 MSps

Actual RX Freq: 98.000000 MHz...

Setting RX Gain: 20.000000 dB...
Actual RX Gain: 20.000000 dB...

Waiting for "lo_locked": ++++++++++ locked.

Press Ctrl + C to stop streaming...
DGot an overflow indication. Please consider the following:
Your write medium must sustain a rate of 20.062041MB/s.
Dropped samples will not be written to the file.
Please modify this example for your purposes.
This message will not appear again.
D
Done!

So, this looks increasingly like your network interface is dropping frames.  TO confirm--this is still under a VM, or on
actual hardware?

What type of Ethernet interface are you using--USB-to-Ethernet devices are known to not work very well because they cannot
sustain high rates, and often reorder frames on the wire.  What kind of cabling are you using?  Have you tried replacing that
cabling?

Also, I'll note that the default master_clock_rate on the N320 is 245.76MHz, which means that your requested 5.0Msps
sample rate cannot be precisely supported.  You can specify "master_clock_rate=200e6" in the device arguments to
request that as a master clock rate, which will allow a 5Msps sample rate.

Also, the gain range on N320 goes up to 75dB, which means unless you have a VERY strong signal, a gain setting of
20dB will likely produce noisy/non-existent results.

2.   What gain settings did you use?
   

[cid:image001.png@01D7C056.3910C600]

[cid:image002.png@01D7C056.3910C600]

3.   What kind of antenna on the antenna port?
   

Antenna Techincal Information
Manufacturer                RF Solutions
PART                            ANT-8WHIP3H-SMA
TYPE                            90DEG HINGED WHIP
FREQUENCY                  868MHz
CONNECTOR                  SMA
FORM                          HINGED WHIP
DB GAIN                      +3dBi
OP TEMPERATURE        -40 to +70oC

4.   Now when I ran the above spectrum analyzer flowgraph, I receive the runtime error as shown below:
   

<<< Welcome to GNU Radio Companion 3.8.1.0 >>>

Block paths:
/usr/share/gnuradio/grc/blocks

Loading: "/home/komro/usrp_spectrum_analyzer.grc"

Generating: '/home/komro/usrp_spectrum_analyzer.py'

Executing: /usr/bin/python3 -u /home/komro/usrp_spectrum_analyzer.py

Warning: failed to XInitThreads()
[INFO] [UHD] linux; GNU C++ version 9.2.1 20200304; Boost_107100; UHD_3.15.0.0-2build5
[INFO] [MPMD] Initializing 1 device(s) in parallel with args: mgmt_addr=192.168.10.2,type=n3xx,product=n320,serial=31F43B7,claimed=False,addr=192.168.10.2
[INFO] [MPM.PeriphManager] init() called with device args clock_source=internal,time_source=internal,product=n320,mgmt_addr=192.168.10.2'. [INFO] [MPM.Rhodium-0] init() called with args clock_source=internal,time_source=internal,product=n320,mgmt_addr=192.168.10.2'
[INFO] [MPM.Rhodium-1] init() called with args `clock_source=internal,time_source=internal,product=n320,mgmt_addr=192.168.10.2'
[INFO] [0/Replay_0] Initializing block control (NOC ID: 0x4E91A00000000004)
[ERROR] [UHD] Exception caught in safe-call.
in ctrl_iface_impl<_endianness>::~ctrl_iface_impl() [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:50
this->send_cmd_pkt(0, 0, true); -> EnvironmentError: IOError: Block ctrl (CE_01_Port_40) no response packet - AssertionError: bool(buff)
in uint64_t ctrl_iface_impl<_endianness>::wait_for_ack(bool, double) [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG; uint64_t = long unsigned int]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:151

[ERROR] [MPMD] Failure during block enumeration: EnvironmentError: IOError: Block ctrl (CE_01_Port_40) no response packet - AssertionError: bool(buff)
in uint64_t ctrl_iface_impl<_endianness>::wait_for_ack(bool, double) [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG; uint64_t = long unsigned int]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:151

Traceback (most recent call last):
File "/home/komro/usrp_spectrum_analyzer.py", line 192, in <module>
main()
File "/home/komro/usrp_spectrum_analyzer.py", line 170, in main
tb = top_block_cls()
File "/home/komro/usrp_spectrum_analyzer.py", line 91, in init
self.uhd_usrp_source_0 = uhd.usrp_source(
File "/usr/lib/python3/dist-packages/gnuradio/uhd/init.py", line 125, in constructor_interceptor
return old_constructor(*args)
File "/usr/lib/python3/dist-packages/gnuradio/uhd/uhd_swig.py", line 2787, in make
return _uhd_swig.usrp_source_make(device_addr, stream_args, issue_stream_cmd_on_start)
RuntimeError: RuntimeError: Failed to run enumerate_rfnoc_blocks()

What is the problem here?

PS: I can still ping the USRP device successfully!
The fact that you got "no response packet" again indicates a network-layer issue.

Also, I'll note that an antenna designed for 800MHz to 1GHz will be next-to-useless for the FM
band.

Also, there's a simple spectrum analyser application, uhd_fft, that comes with the Gnu Radio installation
on Ubuntu.

Looking forward to your kind response.

Regards,
Thangz
Von: Marcus D. Leech patchvonbraun@gmail.commailto:patchvonbraun@gmail.com
Gesendet: Montag, 11. Oktober 2021 18:08
An: Thangaraj Mukara Dhakshinamoorthy thangaraj@komro.netmailto:thangaraj@komro.net; usrp-users@lists.ettus.commailto:usrp-users@lists.ettus.com
Betreff: Re: UHD example rx_samples_to_file fails

On 2021-10-11 8:24 a.m., Thangaraj Mukara Dhakshinamoorthy wrote:
Hello Everyone,

My system config:
Host OS: Windows 10
Guest OS: VirtualBox Ubuntu 20.04.3 LTS
UHD version: 3.15.0.0
GNU Radio version: 3.8.1.0
SDR Device : Ettus USRP N320
My Goal: Use Ettus N320 as Analysis tool (Ex: Spectrum Analyzer)

Console logs:

komro@komro-HP-ProBook-6560b:/usr/lib/uhd/examples$ ./rx_samples_to_file --freq 98e6 --rate 5e6 --gain 20 --duration 10 usrp_samples.dat

Creating the usrp device with: ...
[INFO] [UHD] linux; GNU C++ version 9.2.1 20200304; Boost_107100; UHD_3.15.0.0-2build5
[INFO] [MPMD] Initializing 1 device(s) in parallel with args: mgmt_addr=192.168.10.2,type=n3xx,product=n320,serial=31F43B7,claimed=False,addr=192.168.10.2
[INFO] [MPM.PeriphManager] init() called with device args mgmt_addr=192.168.10.2,time_source=internal,clock_source=internal,product=n320'. [INFO] [MPM.Rhodium-0] init() called with args mgmt_addr=192.168.10.2,time_source=internal,clock_source=internal,product=n320'
[INFO] [MPM.Rhodium-1] init() called with args `mgmt_addr=192.168.10.2,time_source=internal,clock_source=internal,product=n320'
.
.
.
.
[WARNING] [MULTI_USRP] The hardware does not support the requested RX sample rate:
Target sample rate: 5.000000 MSps
Actual sample rate: 5.015510 MSps
Actual RX Rate: 5.015510 Msps...

Setting RX Freq: 98.000000 MHz...
Setting RX LO Offset: 0.000000 MHz...
Actual RX Freq: 98.000000 MHz...

Setting RX Gain: 20.000000 dB...
Actual RX Gain: 20.000000 dB...

Waiting for "lo_locked": ++++++++++ locked.

Press Ctrl + C to stop streaming...
DGot an overflow indication. Please consider the following:
Your write medium must sustain a rate of 20.062041MB/s.
Dropped samples will not be written to the file.
Please modify this example for your purposes.
This message will not appear again.
DDDD
Done!

[ERROR] [UHD] Exception caught in safe-call.
in ctrl_iface_impl<_endianness>::~ctrl_iface_impl() [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:50
this->send_cmd_pkt(0, 0, true); -> EnvironmentError: IOError: Block ctrl (CE_00_Port_33) no response packet - AssertionError: bool(buff)
in uint64_t ctrl_iface_impl<_endianness>::wait_for_ack(bool, double) [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG; uint64_t = long unsigned int]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:151

[ERROR] [UHD] Exception caught in safe-call.
in ctrl_iface_impl<_endianness>::~ctrl_iface_impl() [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:50
this->send_cmd_pkt(0, 0, true); -> EnvironmentError: IOError: Block ctrl (CE_00_Port_30) packet parse error - EnvironmentError: IOError: Expected packet index: 28 Received index: 29
[ERROR] [UHD] Exception caught in safe-call.
in ctrl_iface_impl<_endianness>::~ctrl_iface_impl() [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:50
this->send_cmd_pkt(0, 0, true); -> EnvironmentError: IOError: Block ctrl (CE_01_Port_40) packet parse error - EnvironmentError: IOError: Expected packet index: 566 Received index: 567
Performance within a VM is often very poor.  If you replace the output file with "/dev/null", ,does this change the behavior?

1. What should I do in order to fix this?

2. I tried the fm_receiver flowgraph in GNU Radio, it was running successfully but when I tune the frequency there is nothing I could hear except the first 5 seconds noise!
   That would be a question for the discuss-gnuradio mailing list.

3. I also tried the example 'Spectrum Analyzer' grc program, it was also running without error but there was not much changes/effects when I tune the frequency! Is there something wrong in receiver?
   What gain setting did you use?  What kind of antenna on the antenna port?

Thank you in advance!

Regards,
Thangz

On 2021-10-13 11:34 a.m., Thangaraj Mukara Dhakshinamoorthy wrote:

TRy a longer duration?  Are you doing this in a directory where you have
write permission?

Antennas are generally frequency-specific devices, so an antenna that is
good for UHF is likely not going to work for the low end of VHF, where
the FM band is.

You might look into a "discone" antenna, since they have broad, if
somewhat inefficient, coverage.

Can you use "uhd_fft" to confirm (or not) that you're receiving signals
on the FM band?  Do different gain settings help?

In general, asking "why does my flow-graph not work" questions belong on
the discuss-gnuradio mailing list, not here.

Hello Marcus,

1.  TRy a longer duration?  Are you doing this in a directory where you have write permission?
   

Yes, I have write permissions to ~/Desktop folder, but still no files were created! Also, longer duration doesn't bring anything!

komro@komro-HP-ProBook-6560b:/usr/lib/uhd/examples$ ./rx_samples_to_file --args="master_clock_rate=200e6" --freq 868e6 --rate 5e6 --gain 20 --duration 30 ~/Desktop/usrp_samples.dat

or

komro@komro-HP-ProBook-6560b:/usr/lib/uhd/examples$ ./rx_samples_to_file --args="master_clock_rate=200e6" --freq 868e6 --rate 2e6 --gain 20 --duration 30 ~/Desktop/usrp_samples.dat

or

komro@komro-HP-ProBook-6560b:/usr/lib/uhd/examples$ ./rx_samples_to_file --args="master_clock_rate=200e6" --freq 868e6 --rate 2e6 --gain 20 --duration 40 ~/Desktop/usrp_samples.dat

or

komro@komro-HP-ProBook-6560b:/usr/lib/uhd/examples$ ./rx_samples_to_file --args="master_clock_rate=200e6" --freq 868e6 --rate 2e6 --gain 20 --duration 20 ~/Desktop/usrp_samples.dat

or

komro@komro-HP-ProBook-6560b:/usr/lib/uhd/examples$ ./rx_samples_to_file --args="master_clock_rate=200e6" --freq 868e6 --rate 2e6 --gain 20 --duration 10 ~/Desktop/usrp_samples.dat

Creating the usrp device with: master_clock_rate=200e6...

[INFO] [UHD] linux; GNU C++ version 9.2.1 20200304; Boost_107100; UHD_3.15.0.0-2build5

.

.

.

Setting RX Rate: 2.000000 Msps...

Actual RX Rate: 2.000000 Msps...

Setting RX Freq: 868.000000 MHz...

Setting RX LO Offset: 0.000000 MHz...

Actual RX Freq: 868.000000 MHz...

Setting RX Gain: 20.000000 dB...

Actual RX Gain: 20.000000 dB...

Waiting for "lo_locked": ++++++++++ locked.

Press Ctrl + C to stop streaming...

Done!

(but no files were created)

komro@komro-HP-ProBook-6560b:/usr/lib/uhd/examples$

2.  Can you use "uhd_fft" to confirm (or not) that you're receiving signals on the FM band?  Do different gain settings help?
   

Yes, I could receive fm signals using uhd_fft! Changing gains had some effects on signals output too! But couldn't hear anything when I tried the same frequency/gain settings in GNU Radio. Moreover the Gnuradio console outputs 'UaUaUaUaUaUa.....' when the signal is strong and there was some slight variations in the sound, far away from but a step closer to useful FM radio sound!

[cid:image005.png@01D7C0EF.B93DA2A0]

3.  In general, asking "why does my flow-graph not work" questions belong on the discuss-gnuradio mailing list, not here.
   

Sorry for the trouble, I will do that in future!

Regards,

Thangaraj

Von: Marcus D. Leech patchvonbraun@gmail.com
Gesendet: Mittwoch, 13. Oktober 2021 17:50
An: Thangaraj Mukara Dhakshinamoorthy thangaraj@komro.net; usrp-users@lists.ettus.com
Betreff: Re: AW: AW: UHD example rx_samples_to_file fails

On 2021-10-13 11:34 a.m., Thangaraj Mukara Dhakshinamoorthy wrote:
Hello Marcus,

1.   So, this looks increasingly like your *network* interface is dropping frames.  TO confirm--this is still under a VM, or on
   

actual hardware?
Yes, it is a seperate laptop which runs only ubuntu as main OS.
What type of Ethernet interface are you using--USB-to-Ethernet devices are known to not work very well because they cannot
sustain high rates, and often reorder frames on the wire.  What kind of cabling are you using?  Have you tried replacing that
cabling?

Now I removed the USB to Ethernet adapter and connected the ethernet cable (CAT5E 350MHz cable) directly into laptop!

Also, I'll note that the default master_clock_rate on the N320 is 245.76MHz, which means that your requested 5.0Msps
sample rate cannot be precisely supported.  You can specify "master_clock_rate=200e6" in the device arguments to
request that as a master clock rate, which will allow a 5Msps sample rate.
Done!
Also, the gain range on N320 goes up to 75dB, which means unless you have a VERY strong signal, a gain setting of
20dB will likely produce noisy/non-existent results.
There is strong signal in 868MHz frequency, but still there is no capture file created by the UHD example program!

Console logs:
komro@komro-HP-ProBook-6560b:/usr/lib/uhd/examples$ ./rx_samples_to_file --args="master_clock_rate=200e6" --freq 868e6 --rate 5e6 --gain 20 --duration 10 usrp_samples.dat

Creating the usrp device with: master_clock_rate=200e6...
[INFO] [UHD] linux; GNU C++ version 9.2.1 20200304; Boost_107100; UHD_3.15.0.0-2build5
[INFO] [MPMD] Initializing 1 device(s) in parallel with args: mgmt_addr=192.168.178.61,type=n3xx,product=n320,serial=31F43B7,claimed=False,addr=192.168.10.2,master_clock_rate=200e6
[WARNING] [MPM.RPCServer] A timeout event occured!
[INFO] [MPM.PeriphManager] init() called with device args product=n320,mgmt_addr=192.168.178.61,clock_source=internal,time_source=internal,master_clock_rate=200e6'. [INFO] [MPM.Rhodium-0] init() called with args product=n320,mgmt_addr=192.168.178.61,clock_source=internal,time_source=internal,master_clock_rate=200e6'
[INFO] [MPM.Rhodium-1] init() called with args `product=n320,mgmt_addr=192.168.178.61,clock_source=internal,time_source=internal,master_clock_rate=200e6'
.
.
.
Setting RX Rate: 5.000000 Msps...
Actual RX Rate: 5.000000 Msps...

Setting RX Freq: 868.000000 MHz...
Setting RX LO Offset: 0.000000 MHz...
Actual RX Freq: 868.000000 MHz...

Setting RX Gain: 20.000000 dB...
Actual RX Gain: 20.000000 dB...

Waiting for "lo_locked": ++++++++++ locked.

Press Ctrl + C to stop streaming...

Done!
(but no file created)
TRy a longer duration?  Are you doing this in a directory where you have write permission?

2.   Regarding the Spectrum Analyzer Program, I reduced the sample rate to 2MHz, then it worked perfectly and the fluctuations in the graph were seen clearly without any stop! I also check the uhd_fft program which worked perfectly too!
   

3.   Regarding the FM receiver flowgraph,I tried tuning various FM channel frequencies (88-108 MHz) and gains, but there is no effect other than the noisy sound (always). What should I do to build a FM receiver application using N320 and which antenna should I use (please suggest for multipurpose too)?
   

Antennas are generally frequency-specific devices, so an antenna that is good for UHF is likely not going to work for the low end of VHF, where the FM band is.

You might look into a "discone" antenna, since they have broad, if somewhat inefficient, coverage.

Can you use "uhd_fft" to confirm (or not) that you're receiving signals on the FM band?  Do different gain settings help?

In general, asking "why does my flow-graph not work" questions belong on the discuss-gnuradio mailing list, not here.

[cid:image006.png@01D7C0EF.B93DA2A0]PS: I followed the gnuradio tutorial on usrp fm receiver

Looking forward to your kind response :)

Regards,
Thangaraj

Von: Marcus D. Leech patchvonbraun@gmail.commailto:patchvonbraun@gmail.com
Gesendet: Dienstag, 12. Oktober 2021 17:03
An: Thangaraj Mukara Dhakshinamoorthy thangaraj@komro.netmailto:thangaraj@komro.net; usrp-users@lists.ettus.commailto:usrp-users@lists.ettus.com
Betreff: Re: AW: UHD example rx_samples_to_file fails

On 2021-10-12 5:46 a.m., Thangaraj Mukara Dhakshinamoorthy wrote:
Hello Marcus,

My system config (changed my working environment):
OS: Ubuntu 20.04.3 LTS
OS Type: 64-bit
RAM: 3.8 GB
Processor: Intel Core i5-2450M CPU @2.50GHz x4
UHD version: 3.15.0.0
GNU Radio version: 3.8.1.0
SDR Device: Ettus USRP N320
My Goal: Use Ettus N320 as Analysis tool (Ex: Spectrum Analyzer)

1.   Performance within a VM is often very poor.  If you replace the output file with "/dev/null", ,does this change the behavior?
   

komro@komro-HP-ProBook-6560b:/usr/lib/uhd/examples$ ./rx_samples_to_file --freq 98e6 --rate 5e6 --gain 20 --duration 10  /dev/null

Creating the usrp device with: ...
[INFO] [UHD] linux; GNU C++ version 9.2.1 20200304; Boost_107100; UHD_3.15.0.0-2build5
[INFO] [MPMD] Initializing 1 device(s) in parallel with args: mgmt_addr=192.168.10.2,type=n3xx,product=n320,serial=31F43B7,claimed=False,addr=192.168.10.2
[WARNING] [MPM.RPCServer] A timeout event occured!
[WARNING] [MPM.RPCServer] Attempt to read logs without valid claim from 192.168.10.1
.
.
.

Setting RX Rate: 5.000000 Msps...
[WARNING] [RFNOC] The requested decimation is odd; the user should expect passband CIC rolloff.
Select an even decimation to ensure that a halfband filter is enabled.
Decimations factorable by 4 will enable 2 halfbands, those factorable by 8 will enable 3 halfbands.
decimation = dsp_rate/samp_rate -> 49 = (245.760000 MHz)/(5.000000 MHz)

Actual RX Rate: 5.015510 Msps...

Setting RX Freq: 98.000000 MHz...
Setting RX LO Offset: 0.000000 MHz...
[WARNING] [MULTI_USRP] The hardware does not support the requested RX sample rate:
Target sample rate: 5.000000 MSps
Actual sample rate: 5.015510 MSps

Actual RX Freq: 98.000000 MHz...

Setting RX Gain: 20.000000 dB...
Actual RX Gain: 20.000000 dB...

Waiting for "lo_locked": ++++++++++ locked.

Press Ctrl + C to stop streaming...
DGot an overflow indication. Please consider the following:
Your write medium must sustain a rate of 20.062041MB/s.
Dropped samples will not be written to the file.
Please modify this example for your purposes.
This message will not appear again.
D
Done!

So, this looks increasingly like your network interface is dropping frames.  TO confirm--this is still under a VM, or on
actual hardware?

What type of Ethernet interface are you using--USB-to-Ethernet devices are known to not work very well because they cannot
sustain high rates, and often reorder frames on the wire.  What kind of cabling are you using?  Have you tried replacing that
cabling?

Also, I'll note that the default master_clock_rate on the N320 is 245.76MHz, which means that your requested 5.0Msps
sample rate cannot be precisely supported.  You can specify "master_clock_rate=200e6" in the device arguments to
request that as a master clock rate, which will allow a 5Msps sample rate.

Also, the gain range on N320 goes up to 75dB, which means unless you have a VERY strong signal, a gain setting of
20dB will likely produce noisy/non-existent results.

2.   What gain settings did you use?
   

[cid:image003.png@01D7C0EF.B91E5AD0]

[cid:image004.png@01D7C0EF.B91E5AD0]

3.   What kind of antenna on the antenna port?
   

Antenna Techincal Information
Manufacturer                RF Solutions
PART                            ANT-8WHIP3H-SMA
TYPE                            90DEG HINGED WHIP
FREQUENCY                  868MHz
CONNECTOR                  SMA
FORM                          HINGED WHIP
DB GAIN                      +3dBi
OP TEMPERATURE        -40 to +70oC

4.   Now when I ran the above spectrum analyzer flowgraph, I receive the runtime error as shown below:
   

<<< Welcome to GNU Radio Companion 3.8.1.0 >>>

Block paths:
/usr/share/gnuradio/grc/blocks

Loading: "/home/komro/usrp_spectrum_analyzer.grc"

Generating: '/home/komro/usrp_spectrum_analyzer.py'

Executing: /usr/bin/python3 -u /home/komro/usrp_spectrum_analyzer.py

Warning: failed to XInitThreads()
[INFO] [UHD] linux; GNU C++ version 9.2.1 20200304; Boost_107100; UHD_3.15.0.0-2build5
[INFO] [MPMD] Initializing 1 device(s) in parallel with args: mgmt_addr=192.168.10.2,type=n3xx,product=n320,serial=31F43B7,claimed=False,addr=192.168.10.2
[INFO] [MPM.PeriphManager] init() called with device args clock_source=internal,time_source=internal,product=n320,mgmt_addr=192.168.10.2'. [INFO] [MPM.Rhodium-0] init() called with args clock_source=internal,time_source=internal,product=n320,mgmt_addr=192.168.10.2'
[INFO] [MPM.Rhodium-1] init() called with args `clock_source=internal,time_source=internal,product=n320,mgmt_addr=192.168.10.2'
[INFO] [0/Replay_0] Initializing block control (NOC ID: 0x4E91A00000000004)
[ERROR] [UHD] Exception caught in safe-call.
in ctrl_iface_impl<_endianness>::~ctrl_iface_impl() [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:50
this->send_cmd_pkt(0, 0, true); -> EnvironmentError: IOError: Block ctrl (CE_01_Port_40) no response packet - AssertionError: bool(buff)
in uint64_t ctrl_iface_impl<_endianness>::wait_for_ack(bool, double) [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG; uint64_t = long unsigned int]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:151

[ERROR] [MPMD] Failure during block enumeration: EnvironmentError: IOError: Block ctrl (CE_01_Port_40) no response packet - AssertionError: bool(buff)
in uint64_t ctrl_iface_impl<_endianness>::wait_for_ack(bool, double) [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG; uint64_t = long unsigned int]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:151

Traceback (most recent call last):
File "/home/komro/usrp_spectrum_analyzer.py", line 192, in <module>
main()
File "/home/komro/usrp_spectrum_analyzer.py", line 170, in main
tb = top_block_cls()
File "/home/komro/usrp_spectrum_analyzer.py", line 91, in init
self.uhd_usrp_source_0 = uhd.usrp_source(
File "/usr/lib/python3/dist-packages/gnuradio/uhd/init.py", line 125, in constructor_interceptor
return old_constructor(*args)
File "/usr/lib/python3/dist-packages/gnuradio/uhd/uhd_swig.py", line 2787, in make
return _uhd_swig.usrp_source_make(device_addr, stream_args, issue_stream_cmd_on_start)
RuntimeError: RuntimeError: Failed to run enumerate_rfnoc_blocks()

What is the problem here?

PS: I can still ping the USRP device successfully!
The fact that you got "no response packet" again indicates a network-layer issue.

Also, I'll note that an antenna designed for 800MHz to 1GHz will be next-to-useless for the FM
band.

Also, there's a simple spectrum analyser application, uhd_fft, that comes with the Gnu Radio installation
on Ubuntu.

Looking forward to your kind response.

Regards,
Thangz
Von: Marcus D. Leech patchvonbraun@gmail.commailto:patchvonbraun@gmail.com
Gesendet: Montag, 11. Oktober 2021 18:08
An: Thangaraj Mukara Dhakshinamoorthy thangaraj@komro.netmailto:thangaraj@komro.net; usrp-users@lists.ettus.commailto:usrp-users@lists.ettus.com
Betreff: Re: UHD example rx_samples_to_file fails

On 2021-10-11 8:24 a.m., Thangaraj Mukara Dhakshinamoorthy wrote:
Hello Everyone,

My system config:
Host OS: Windows 10
Guest OS: VirtualBox Ubuntu 20.04.3 LTS
UHD version: 3.15.0.0
GNU Radio version: 3.8.1.0
SDR Device : Ettus USRP N320
My Goal: Use Ettus N320 as Analysis tool (Ex: Spectrum Analyzer)

Console logs:

komro@komro-HP-ProBook-6560b:/usr/lib/uhd/examples$ ./rx_samples_to_file --freq 98e6 --rate 5e6 --gain 20 --duration 10 usrp_samples.dat

Creating the usrp device with: ...
[INFO] [UHD] linux; GNU C++ version 9.2.1 20200304; Boost_107100; UHD_3.15.0.0-2build5
[INFO] [MPMD] Initializing 1 device(s) in parallel with args: mgmt_addr=192.168.10.2,type=n3xx,product=n320,serial=31F43B7,claimed=False,addr=192.168.10.2
[INFO] [MPM.PeriphManager] init() called with device args mgmt_addr=192.168.10.2,time_source=internal,clock_source=internal,product=n320'. [INFO] [MPM.Rhodium-0] init() called with args mgmt_addr=192.168.10.2,time_source=internal,clock_source=internal,product=n320'
[INFO] [MPM.Rhodium-1] init() called with args `mgmt_addr=192.168.10.2,time_source=internal,clock_source=internal,product=n320'
.
.
.
.
[WARNING] [MULTI_USRP] The hardware does not support the requested RX sample rate:
Target sample rate: 5.000000 MSps
Actual sample rate: 5.015510 MSps
Actual RX Rate: 5.015510 Msps...

Setting RX Freq: 98.000000 MHz...
Setting RX LO Offset: 0.000000 MHz...
Actual RX Freq: 98.000000 MHz...

Setting RX Gain: 20.000000 dB...
Actual RX Gain: 20.000000 dB...

Waiting for "lo_locked": ++++++++++ locked.

Press Ctrl + C to stop streaming...
DGot an overflow indication. Please consider the following:
Your write medium must sustain a rate of 20.062041MB/s.
Dropped samples will not be written to the file.
Please modify this example for your purposes.
This message will not appear again.
DDDD
Done!

[ERROR] [UHD] Exception caught in safe-call.
in ctrl_iface_impl<_endianness>::~ctrl_iface_impl() [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:50
this->send_cmd_pkt(0, 0, true); -> EnvironmentError: IOError: Block ctrl (CE_00_Port_33) no response packet - AssertionError: bool(buff)
in uint64_t ctrl_iface_impl<_endianness>::wait_for_ack(bool, double) [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG; uint64_t = long unsigned int]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:151

[ERROR] [UHD] Exception caught in safe-call.
in ctrl_iface_impl<_endianness>::~ctrl_iface_impl() [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:50
this->send_cmd_pkt(0, 0, true); -> EnvironmentError: IOError: Block ctrl (CE_00_Port_30) packet parse error - EnvironmentError: IOError: Expected packet index: 28 Received index: 29
[ERROR] [UHD] Exception caught in safe-call.
in ctrl_iface_impl<_endianness>::~ctrl_iface_impl() [with uhd::endianness_t _endianness = uhd::ENDIANNESS_BIG]
at /build/uhd-FRfZNJ/uhd-3.15.0.0/host/lib/rfnoc/ctrl_iface.cpp:50
this->send_cmd_pkt(0, 0, true); -> EnvironmentError: IOError: Block ctrl (CE_01_Port_40) packet parse error - EnvironmentError: IOError: Expected packet index: 566 Received index: 567
Performance within a VM is often very poor.  If you replace the output file with "/dev/null", ,does this change the behavior?

1. What should I do in order to fix this?

2. I tried the fm_receiver flowgraph in GNU Radio, it was running successfully but when I tune the frequency there is nothing I could hear except the first 5 seconds noise!
   That would be a question for the discuss-gnuradio mailing list.

3. I also tried the example 'Spectrum Analyzer' grc program, it was also running without error but there was not much changes/effects when I tune the frequency! Is there something wrong in receiver?
   What gain setting did you use?  What kind of antenna on the antenna port?

Thank you in advance!

Regards,
Thangz

On 2021-10-14 5:36 a.m., Thangaraj Mukara Dhakshinamoorthy wrote:

Use the --file argument to specify where to write the file--the
interface to this program changed a bit a while ago, so
  if you don't specify "--file" it writes to "usrp_samples.dat" in the
current directory.  Any argument that doesn't begin with a "--something"
  is quietly ignored, it seems.

It also apparently quietly ignores write errors due to permissions
issues (you were running it in the examples directory which is not
writeable to
  an ordinary user).