Solution
DAQmx Property Nodes by default
only show supported properties for devices in your system. This implicitly means that reference clock synchronization is not supported by the PXIe-6535. This can also be verified by looking at the
device routes in NI MAX, and seeing that
PXI_Clk10 or
PXIe_Clk100 are not available device routes.
An alternative to reference clock synchronization is to export the sample clock from the PXIe-6535 or another module (the master device) onto a PXI trigger line, and then route the slave PXIe-6535's sample clock to that line. Observing the device routes available for the PXIe-6535, the digital output sample clock (
/DO/SampleClock) only can route to
PXI_Trig7.
Here is a LabVIEW VI example that shows a basic sample clock synchronization. Note that you do not need to configure a start trigger because sharing a clock implicitly synchronizes the first sample of each module.