Low-cost field bus remote input-output system

Abstract

The invention discloses a low-cost field bus remote input-output system comprising a control module and an I/O (Input/Output) module; a control program is stored in the control module; the control module is used for managing the I/O module through an internal bus; the acquisition and the conversion of field signals are finished by the I/O module; and field equipment is controlled by the control module through the I/O module. An MODBUS communication protocol is stored in the control module which operates an MODBUS-RTU protocol stack; the MODBUS communication protocol comprises an MODBUS slave station protocol and an MODBUS master station protocol; and the MODBUS master station protocol realizes data acquisition and remote monitoring of the field equipment through the MODBUS slave station protocol. The low-cost field bus remote input-output system is simple in structure and convenient to install. Due to the adoption of RS-485 bus, the workload for design and installation is reduced, and the investment is saved. The low-cost field bus remote input-output system can realize real-time monitoring and controlling functions and has rather high real-time property and reliability.

Description

technical field [0001] The invention relates to the field of automatic control, in particular to a low-cost field bus remote input and output system. Background technique [0002] With the increasing popularity of 32-bit single-chip applications, the degree of information sharing continues to increase. For small embedded devices centered on single-chip application systems, it has become the focus of electronic product development today. [0003] Among them, the technical difficulties of using the single-chip microcomputer to realize the embedded solution are: 1. How to use the limited resources of the single-chip microcomputer to process the information with the MODBUS protocol to make it into a data packet that can be transmitted on the RS485. 2. Run the real-time kernel in the microcontroller. Starting from solving this technical problem, there are currently several solutions as follows: [0004] 1.Gateway+private network: Use a dedicated network (such as RS-232, RS-485...

AI Technical Summary

Problems solved by technology

Disadvantages: a. Need to rely on PC as the gateway for protocol conversion. In the case of scattered single-chip systems, dedicated network wiring is extremely inconvenient; b. Need to install special protocol conversion software on the PC, which is usually provided by a dedicated first Provided by third-party software vendors, the cost is relatively high

However, this solution has the following disadvantages: it is necessary to purchase or select free RTOS development software, which requires high development capabilities of developers

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