And to complete Contr_Comms explanation, the language used is called 'CIP', (Control and Information Protocol).
CIP is also used on DeviceNet, ControlNet and the ControlLogix 1756 backplane. This is why the bridging and routing works so well in the CLX system, it is because the bridge modules like 1756-ENBT, or CNB's or DNB's although they have to manage converting between different network media, do not have to translate between fundamentally different languages as well.