Hi 郁哉 芦澤,
Do you refer to the 'mux' and 'demux' from the Simulink basic library? These two blocks have the default signal order from top to bottom. Here is an example about mux and demux:
If you want to control the order of signal, you can use 'Bus Creator' and 'Bus Selector'. Alternatively, use ' Bus Element'. More advanced way is to create bus object which gives you more flexibilities to control/define the bus signals.
Best,
Christine
