The files that start with sx_
stem from the initial submission, where we simulated noise applied to all modules (global stimulation). In this case, the freuqency is the total stimulation rate.
The rest (mostly sy_
) were created later, applying 20Hz extra, only in the lower two modules (orange). Also, for those topologies, the in-degree was fixed to 30 (this was not the case for those above).