Hello,
I am performing a 3x1 MISO wireless communication using 3 USRP-2954R devices. With each transmitter located on a separate device, and the receiver located on a device of choice (typically dev0). The LabVIEW code includes a repeating loop that modifies the position of the Rx antenna, and transmits an identical waveform each time. All USRP devices share the same 10 MHz reference and PPS signal, obtained from a CDA-2990 clock distributor. All devices are time synchronized.
Each iteration in itself operates as expected. However, at certain iterations one of the following errors (see below) appear and interrupt the loop, stopping the program from finishing operation. In all cases, the error seems to be related to a packet loss in the communication between LabVIEW and the USRPs. The trigger for the errors is hard to determine, as they seemingly happen arbitrarily every 20-100 iterations.
I have included the VI in attachment. Note that it does call external Matlab functions for further signal processing, they are however not at the cause of the issue.
Error -1074118627 occurred at niUSRP Write Tx Data (2D CDB).gvi:
A runtime or configuration error occurred.
Code: 312
Details: EnvironmentError: IOError: [0/Radio_0] user_reg_read32() failed: EnvironmentError: IOError: [0/Radio_0] sr_read32() failed: EnvironmentError: IOError: Block ctrl (CE_01_Port_40) packet parse error - EnvironmentError: IOError: Expected packet index: 3958 Received index: 1928
Error -1074118627 occurred at niUSRP Initiate.gvii:
A runtime or configuration error occurred.
Code: 312
Details: EnvironmentError: IOError: [0/Radio_1] user_reg_read32() failed: EnvironmentError: IOError: [0/Radio_1] sr_read32() failed: EnvironmentError: IOError: Block ctrl (CE_02_Port_50) no response packet - AssertionError: bool(buff)
in unsigned __int64 __cdecl ctrl_iface_impl::wait_for_ack(const bool)
at P:/Measurements/FlexRIO/SWCode/usrp/niuhd2/trunk/18.0/objects/uhdrepo/host/lib/rfnoc/ctrl_iface.cpp:204
Note that both errors above have occured at both nodes and do not exclusively happen at either Tx or Rx.
Additionally, when moving the receiver to another device (eg. dev0 as above, to dev1), the IOError mention above changes to [1/Radio_0] and [1/Radio_1], such that the problem seems to originate at the USRP that uses both a Tx and Rx channel simultaneously.
Additionally, in some case the following errors appears:
Error -1074118650 occurred at niUSRP Fetch Rx Data (2D CDB).gvi:
Possible reason(s):
Timeout exceeded before packet received or sent. Not all samples may have been received or sent. Consider increasing timeout.
Upon writing a catch to detect and suppress these errors for further investigation, the next iterations in the loop, both at Tx and Rx, yield the following errors successively:
At niUSRP Write Tx Data (2D CDB).gvi:
- EnvironmentError: IOError: 1/Radio_0 user_reg_read64() failed: EnvironmentError: IOError: [1/Radio_0] sr_read64() failed: EnvironmentError: IOError: Block ctrl (CE_01_Port_40) packet parse error - EnvironmentError: IOError: Expected packet index: 3129 Received index: 3130
niUSRP Get Time.gvi:<ERR>A runtime or configuration error occurred.
- EnvironmentError: IOError: 1/Radio_0 user_reg_read64() failed: EnvironmentError: IOError: [1/Radio_0] sr_read64() failed: EnvironmentError: IOError: Block ctrl (CE_01_Port_40) packet parse error - EnvironmentError: IOError: Expected packet index: 3130 Received index: 3131
- etc.
At niUSRP Initiate.gvi:
- EnvironmentError: IOError: [1/Radio_1] user_reg_read32() failed: EnvironmentError: IOError: [1/Radio_1] sr_read32() failed: EnvironmentError: IOError: Block ctrl (CE_02_Port_50) packet parse error - EnvironmentError: IOError: Expected packet index: 3485 Received index: 3484
- EnvironmentError: IOError: [1/Radio_1] user_reg_read32() failed: EnvironmentError: IOError: [1/Radio_1] sr_read32() failed: EnvironmentError: IOError: Block ctrl (CE_02_Port_50) packet parse error - EnvironmentError: IOError: Expected packet index: 3486 Received index: 3485
-etc.
That is, there is a 1 offset between the expected and received packet index at all following iterations.
Any help in solving this issue is most welcome,
Thanks in advance.
