Design And Implementation Of CT Injector Interface Based On CANopen Protocol

CAN-bus has obvious advantages in reliability, real time, flexibility, ease of use, transmission distance, low coast etc. of communication capabilities, it became one of the most promising fieldbuses in industry. CANopen is a CAN-based higher-layer protocols, so far, it has been used in various application areas, for example, medical equipment, off-road vehicles, ships electronic equipment, railway application or building antomation.Previous communication between the injector and diagnostic equipment is achieved by the artificial way of doctors and assistants or using electronic interfaces defined by the manufacturer. Becaused of this, CiA developed a specialized application specification CiA 425, this device specification specifies an open communication interface, which is dedicated to the communication between the imaging medical device and auxiliary equipment. The main purpose of this paper is to design a communication interface of CT injector for the communication between CT scanner and injector. For the CANopen protocol, China mostly research theory, this technique is rarely used in China. This paper just apply Canopen technology, Which realize the communication of master-slave mode, it has a positive effect on the development of domestic CANopen technology.The hardware and software of injector interface are respectively designed in this paper, which mostly apply CAN bus technology, CANopen protocol,Microcanopen protocol stack. In the process of hardware design, it describes the funcition of each module of injector interface and the selection process of the main processor and CAN transceivers, furthermore, it detailedly describes the circuit design process of CAN module. In the process of software design, it mostly introduces the whole structure of software design of the CT injector interface, the design of CAN module and application layer protocol. CT scanner is made to communicate with injector and the communication data are displayed in the serial port by setting up experiment platform. It finds that PDO, SDO, NMT and other communication objects can be normally transmited, so the communication between CT scanner and injector is successfully fulfilled by applying CAN bus technology and CANopen protocol.