I am attempting to synchronize the phase of the analyzer and generator of a NI PXIe-5646R using niRFSA and niREFSG with the following resources:
- http://zone.ni.com/reference/en-XX/help/372058N-01/vstdevices/5646_rfsa_gsynchronization/
I'm using the PXI_CLK10 of the Chassis backplane as the reference clock for both RFSG and RFSA. The center frequency is 836 MHz and the IQ-rate is 160 MHz. The LO_in and LO_out terminals are correctly connected. The RF_out and RF_in are connected with the shortest possible wire (I would reckon about 5 cm).
The LabVIEW code seems to be correctly implemented as succesive measurements result in the exact same phase delay between the output of the RFSG and the input of the RFSA. The phase delay between RFSG and RFSA is however an non-integer number somewhere between 154 and 155 samples (with a sample being equal to 6.25 nanoseconds). The 5cm wire is unable to explain this huge sample delay.
Any ideas on the source of this sample delay? Or even better, on how to negate it without post-processing?
Thank you for your time.