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FMCOMMS1 Rev B vs Rev C

Question asked by mike.baker Employee on Apr 16, 2014
Latest reply on Jan 6, 2015 by dpu

Yesterday I received a second FMCOMMS1 board.

This new one is a Rev C, while the last one was a Rev B.


I plugged it into my ML605 and tried to run the same Simulink code, but it seems that the TX portion does not respond correctly.


When I hook up my spectrum analyzer, I see a carrier at -44dBm but I do not see any sidebands.

The Rev B version on the other hand shows a carrier at around 4dBm and clearly defined sidebands from the QPSK modulation.


Also, the synchronization between the Simulink block and the FMCOMMS1 had intermittent problems:


The error above happens when pushing “Synchronize” in the Simulink transmitter block: (see attachment)



When pushing repeatedly, it will eventually synchronize, but not all Device Values are identical to the Desired Values (See DAC Sampling Rate and Interpolation factor):



So I wonder if I have a board communication problem here ?


The Rev B does not show any of these symptoms.