How should I script a show with multiple controllers?
The easiest way is to start by thinking of one controller as the master. The choice of a master should be determined by what triggers the most sequences, or where the logic needs to reside. Usually, this means that a V16 is the master and IO64s are the slaves. But for a show with a lot of logic operating on the parallel inputs, and very straightforward serial handling, just the opposite could be optimal.
Next, create empty scripts for all of the units, naming the I/O resources in meaningful ways and configuring the serial ports. Then, go to the master controller and use the product wizard in the port configuration menu to select the script that will be in the unit connected to each port.
Now, you can write the script for your master unit and it will have visibility of all the resources of the slaves.