DT680E GJR2923100R1 DT680B-E Computer Serial Interface

DT680E GJR2923100R1 DT680B-E as a standard computer serial interface has been widely used, at the same time, with the rapid development of fieldbus technology, with good real-time, high reliability, simple structure and other advantages of the CAN bus in the measurement and control system is also more and more adopted, but due to the two bus structure, communication protocols and transmission characteristics of the two are different. However, due to the different bus structures, communication protocols and transmission characteristics of the two, it brings a lot of inconvenience to the connection between different devices. Therefore, how to achieve the communication between CAN node and RS232 serial port in the simplest way has become an unavoidable problem in engineering practice.

DT680E GJR2923100R1 DT680B-E is not a TTL level interface standard, but the negative logic, that is, the logic “1” for -3 V ~ 15 V; logic “0” for +3 V ~ +15 V; and CAN bus is the use of the “explicit” and “implicit” two complementary logic values, “0” and “1”, whose signals are represented in the form of a “differential” voltage between the two lines. The signals are in the form of “differential” voltages between the two lines. This results in a signal voltage mismatch between the two buses. Normal communication cannot be carried out directly, therefore, the corresponding hardware interface circuit is needed to realise the level standard conversion.

DT680E GJR2923100R1 The RS232 communication of DT680B-E belongs to asynchronous serial communication. Generally two-point transmission, the data format of each frame is usually: start bit + data bits + parity bit (can be omitted) + stop bit; the format of each data packet is usually: data packet header + data byte + checksum (overflow is not counted). CAN communication belongs to the bus communication, there can be more than one node at the same time, so the communication protocol is relatively complex, here to standard frame transmission as an example, its data format is usually as listed in Table 1. Therefore, software processing is required to achieve the conversion of the communication protocol.