This example shows how to use dataflow to force two devices to run in a relatively synchronised manner using while loop timing, even if they do not share a clock (for example, two USB devices in the same PC). It's based on the setup shown in Figure 6 of this white paper, but I've not managed to find any example code of it when customers have asked, so I thought I'd upload my own version.
The synchronisation here is not particularly accurate, particularly not at high read frequencies where it may miss data, as it's entirely based on the software's loop rate rather than any kind of actual external timing or synchronisation, but for relatively simple DAQ tasks, it may help some people with getting started.