Profibus-DP photoelectric signal conversion system

Abstract

The invention discloses a Profibus-DP photoelectric signal conversion system. The Profibus-DP photoelectric signal conversion system comprises a photoelectric converter, a data receiving and transmitting logic control circuit and an electric isolation and differential signal conversion circuit, wherein the photoelectric converter receives optical signals and converts the optical signals into TTL level signals, or receives the TTL level signals and converts the TTL level signals into the optical signals; the data receiving and transmitting logic control circuit comprises a three-state buffer connected with the photoelectric converter, and a receiving and transmitting control end of the three-state buffer is sequentially connected with a delay circuit and a first Schmitt inverter; the electric isolation and differential signal conversion circuit comprises a differential level converter, the differential level converter is connected with the photoelectric converter and is used for receiving and transmitting the TTL level signals, the differential level converter is connected with an output end of the first Schmitt inverter and is used for receiving, transmitting and controlling temporal logic signals, and an output end of the differential level converter is connected with a Profibus-DP bus and is used for receiving and transmitting Profibus-DP differential signals. The Profibus-DP photoelectric signal conversion system provided by the invention has greater real-time performance and flexibility.

Description

technical field [0001] The invention relates to the technical field of photoelectric conversion, more specifically, the invention relates to a Profibus-DP photoelectric signal conversion system. Background technique [0002] Profibus-DP is a fieldbus communication method commonly used in industrial automation fields such as electric power, petrochemical, and machinery manufacturing. It is mainly used for communication between equipment-level control systems and distributed I / O. Its physical layer adopts a differential signal transmission method. It is compatible with Profibus -PA (ProcessAutomation) and Profibus-FMS (FieldbusMessageSpecification) jointly constitute the Profibus standard, which has the characteristics of high speed and low cost. With the development of automation technology, the communication network is becoming more and more complex, the communication distance is getting farther and farther, and the requirements for the reliability of digital communication a...

AI Technical Summary

Problems solved by technology

However, both of these two schemes realize the mutual conversion of photoelectric differential signals at the data link layer. The conversion process has a large delay and can only be packaged and transmitted after receiving the data packet. The real-time performance is poor, and the baud rate Presetting is required, and data that does not meet the preset baud rate cannot be transmitted correctly

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