sometime pyadi receives on only first 2 channel instead of all 4 channel on FMCOMMS5

Question

Run below code on ZC702 with Aug 3 2022 image: 
 
 import time 
 import adi 
 
 sdr = adi.FMComms5( "ip:127.0.0.1" ) 
 
 record_duration = 0.25 * 1e-3 
 rx_lo = 2412000000 
 rx_gain = 30 
 rx_rf_bandwidth = 20000000 
 sample_rate = 20000000 
 
 sdr.sample_rate = sample_rate 
 sdr.rx_rf_bandwidth = rx_rf_bandwidth 
 sdr.rx_rf_bandwidth_chip_b = rx_rf_bandwidth 
 
 sdr.rx_lo = rx_lo 
 sdr.rx_lo_chip_b = rx_lo 
 
 gain_control_mode = "manual" 
 sdr.gain_control_mode_chan0 = gain_control_mode 
 sdr.gain_control_mode_chan1 = gain_control_mode 
 sdr.gain_control_mode_chip_b_chan0 = gain_control_mode 
 sdr.gain_control_mode_chip_b_chan1 = gain_control_mode 
 
 sdr.rx_hardwaregain_chan0 = rx_gain 
 sdr.rx_hardwaregain_chan1 = rx_gain 
 sdr.rx_hardwaregain_chip_b_chan0 = rx_gain 
 sdr.rx_hardwaregain_chip_b_chan1 = rx_gain 
 
 sdr.rx_enabled_channels = [ 0 , 1 , 2 , 3 ] 
 
 # this is buffer size in samples for one channel 
 rx_buffer_size = int (record_duration * sample_rate) 
 sdr.rx_buffer_size = rx_buffer_size 
 
 time.sleep( 1 ) # reserve for FPGA to response 
 
 data = sdr.rx() 
 
 for idx in range ( 10 ): 
 print ( " %5d + %5d j %5d + %5d j %5d + %5d j %5d + %5d j" % ( 
 np.real(data[ 0 ][idx]), np.imag(data[ 0 ][idx]), 
 np.real(data[ 1 ][idx]), np.imag(data[ 1 ][idx]), 
 np.real(data[ 2 ][idx]), np.imag(data[ 2 ][idx]), 
 np.real(data[ 3 ][idx]), np.imag(data[ 3 ][idx]))) 
 
 sdr.rx_destroy_buffer() 
 
 Four running result are shown as below: 
 analog@analog:~/workspace/fmcomms5_py $ python3 fmcomms5_py_source.py -2+ 1j 1+ 0j -3+ -10j -1041+-1041j -1+ 0j -3+ -1j -3+ -10j -1041+-1041j 0+ 2j -2+ 0j -3+ -10j -1041+-1041j 0+ -1j 1+ 0j -3+ -10j -1041+-1041j 0+ 0j 1+ 2j -3+ -10j -1041+-1041j -1+ 0j -1+ 1j -3+ -10j -1041+-1041j 0+ -2j -1+ 1j -3+ -10j -1041+-1041j 0+ 1j 1+ 0j -3+ -10j -1041+-1041j -1+ 0j 3+ 0j -3+ -10j -1041+-1041j 1+ 0j -2+ -1j -3+ -10j -1041+-1041j analog@analog:~/workspace/fmcomms5_py $ python3 fmcomms5_py_source.py -1+ 0j -1+ -2j 1+ 0j 0+ 1j 1+ 0j -1+ -2j 1+ 0j 1+ 2j 0+ 1j 0+ 1j -1+ 0j -1+ 1j 0+ 1j -1+ 0j 1+ -1j -2+ 0j -1+ 1j 1+ 0j 0+ 1j 0+ 0j 0+ -1j 2+ -1j -1+ -1j -1+ 0j 0+ 0j 1+ 0j -1+ -1j 1+ 0j 1+ 0j 1+ 0j -1+ 0j 0+ 0j -1+ -2j 1+ 1j 0+ 0j -3+ 1j 0+ -1j -2+ 0j -1+ 1j 0+ 1j 
 
 It is easy to see that ch0/1 are correct for two running. But ch2/3 are not correct for the first running. When ch2/3 are correct are totally randomly, sometimes it can repeat the error for tens time.

travisfcollins · Accepted Answer

This likely happens since FMComms5 relies upon MCS to do the alignment of the data frames from the transceivers. This only happens if you have libad9361-iio (and python bindings for it). You can see the MCS call here: https://github.com/analogdevicesinc/pyadi-iio/blob/master/adi/fmcomms5.py#L81 
 Try installing the libad9361 bindings. 
 -Travis)