Studying On Monitoring Communication System For Tunnel Environment Of The Underground Cable Based On Canopen Protocol

With the social and economic rapid development, expanding the constant of the city,the city’s demand for electricity is increasing, the urban power grid construction hasgradually excessed overhead network to the underground cable network. So it has a hugechallenge for the reliability and security of city power supply. It is particularly important toreal-time monitor environmental conditions of the underground cables. Currently thereal-time monitoring systems use485bus or PLC, and with the development of field bustechnology, compared to conventional bus technology, the CAN bus technology has betterreal-time performance and reliability. So it is widely used in automotive control systemsand embedded systems, and CANopen protocol is a common international standardprotocol based on CAN bus technology in the automotive and automation to achieve awide range of applications.Firstly, it analyzes in detail the CAN bus and CANopen protocols. It designs ofunderground cables environmental monitoring system based on CAN bus CANopenprotocol for the issue of the implementation of the functional. Secondly, for hardware, itmainly completes the auxiliary circuit design, for example, the power circuit, reset circuit,clock circuit, and it focuses on the design of analog and digital modules. It includes thehardware circuit design of analog acquisition, digital input and output, and CAN buscommunication, and products PCB circuit board and soldered into physical. Also itincludes the software design of MCU functions and CANopen protocol in CANcommunication. In the CANopen protocol stack, it achieves its object dictionary definition,and the modular package of the various objects and communications applications. ForCANopen protocol slave, its mainly functions is to achieve the PDO, SDO function,heartbeat packets function, NMT and LSS features functional. The design of these twomodules sends the analog and digital signals to the CAN bus, and accepts the managementand control commands from the primary node on the bus, give the full the advantages ofCANopen object dictionary. Finally, the designed modules connect with a PC via a USB-CAN adaptor. The module station can be tested via the CANpro protocol analysisplatforms, the results show that the underground cable environment monitoring systembased on CAN bus can real-time reliability monitor of underground cables environmentalin some cases, and achieve good each function of CANopen protocol from station, toacquire requirements of the predetermined design.