Example code for stimulus/response on PXI 5411 (arb mode)and PXI 5620

[blakney]

For my application I need to be able to provide a signal from a PXI 5411 and receive on a PXI 5620. This works except that the clocks run independently such that when one coadds multiple scans together the jitter introduces a phase shift which nullifies the signal to noise advantage from coadding of scans.

I need some clues as to whether I can lock the two boards to the backplane and expect that to solve my problem or if I need to use an independent external clock and lock both boards to a 40 MHz signal (the lower of the two clock speeds).

Any links to example code (CVI) would be appreciated.

Greg

[Andy_Hinde]

You should first try locking both instruments to the PXI backplane 10 MHz reference clock and see if this solves the problem. You can lock the PXI-5620 to the PXI backplane with the following NI-Scope function call:

niScope_ConfigureClock (scopeHandle, NISCOPE_VAL_EXTERNAL, NISCOPE_VAL_NO_SOURCE, NISCOPE_VAL_NO_SOURCE, NISCOPE_VAL_FALSE)

'scopeHandle' will be the variable containing the NI-Scope instrument handle created by the niScope_init() routine.

You can lock the PXI-5411 to the PXI backplane 10 MHz reference clock with the following function calls:

niFgen_ConfigureRefClockSource (arbHandle, NIFGEN_VAL_PXI_CLK10)

niFgen_ConfigureRefClockFrequency (arbHandle, 10E6)

'arbHandle' will be the variable containing the NI-FGEN instrument handle cr
eated by the niFgen_init() routine.