Modular robots (MRs) consist of unique robots which interconnect and work as a collective to perform objectives. Coordinating these robots rely on robust communication, as modules moving independently can lead to damaging behaviour. We present a robust structure for modular robot communication, implemented and tested on a new MR. The structure has different communication protocols depending on the importance and bandwidth of the exchanged information, has fast error responses, and considerations which allow for two modules to actuate the same joint. We evaluate the wireless protocols, novel error response, and coordinated actuation empirically, validating the system on a new modular robot, the Mori3. We find two wireless protocols can be used to balance speed and reliability; transmitting errors through both wireless and serial is more consistent and faster; and sharing motor targets, control variables, and measurements allow for motors to operate a shared joint with equal efforts.