Normal operation of Hotsync used for substituting module data if a new module is inserted in the rack.

But what happens when a Controller Card with enabled hotsync is removed and put back later?

Meanwhile the modules parameter settings have changed. Will be these changes be overwritten by hotsync data?

The answer is no.

A RCT Controller card which is installed in the system, detects that it is new and first updates its own parameter backup data and proceeds then with normal operation.