This part of GB/T28029 specifies the data communication bus within the marshalling based on CANopen technology. CANopen is designed for, but not limited to, industrial automation applications. These applications can include input/output modules, motion controllers, human-machine interfaces, sensors, closed-loop controllers, encoders, hydraulic valves, or programmable controllers. In the field of rail transit, the CANopen network is used for sub-systems within the marshalling, such as brake control systems, internal combustion transmission control systems, and internal/external lighting control systems. In addition, the CANopen network is used as a marshalling network to realize data exchange between different subsystems within the same rail vehicle or a group of rail vehicles in the same marshalling network. This part applies to the devices and equipment of the CANopen marshalling network in the TCN architecture specified in GB/T28029.1. This section applies to the consistency check of the independent TCN implementation itself, and is also a prerequisite for further interoperability checks between different TCN implementations. This section applies to open train communication system architecture. If the supplier and the user agree through consultation, this section can also be applied to closed trains and multi-unit trains.