A word of caution for those who use ControlChain library and who power up their Arduino shield based devices over Control Chain RJ45 cable, and follow the examples from the lib, like Button.ino.
Make sure you first create the cc device itself with
newDevice, then create all the actuators you need, and only then call
begin() - a function that starts up serial communication over Control Chain link.
Button.ino (and other examples for that matter) has it the other way 'round, it first calls
begin(), and then creates the device and actuators, so what you may find yourself with is that a handshake happens before the actuators are created, and your MOD device will see a Control Chain device with no actuators connected.
This does not happen if you use external power with your Arduino shield device and power it up before plugging in a Control Chain cable.
Hope this helps!