thanks for all the input!
I agree that the master/slave definition in this case is a little off, but usually the one who initiates the communication would be called the master which is why I chose the above labeling.
I did some tests with I2C but it wasn't fast enough for the application I had in mind.
missing a reading now and then will not be a problem as long as it doesn't happen too often.
Basically it is a low resolution large sensor array that will track objects and since I am aiming for high sampling rate an occasional lost or corrupt reading will be updated soon during the next cycle (or can even be corrected through interpolation on the software side).
So as long as it is the exception to miss a reading it won't matter.
[side note: I am aware that there seem to be a lot of different or "better" approaches like using cmos-sensors, cameras etc. but this design has been chosen for specific reasons and cannot be replaced]
Thank you very much for the schematics, it looks very interesting.
I think I will first try to reduce the total amount of modules in the system and then see if I can get this synchronization to work.
Thanks again for all the input, it is much appreciated!
Have a nice weekend!