With the rapid development of Industrial Internet of Things (IIoT), networked devices are more and more widely used in the industrial field.Cellular Modem is an important networking equipment.It is responsible for establishing a stable and reliable data transmission channel between the industrial site and the remote server.As a common communication protocol, Modbus is widely used in industrial automation.This article will briefly introduce the knowledge of networking equipment to the traditional pre-transformation industry and the Internet of Things industry.The process of Cellular Modem using Modbus transport protocol is discussed in detail.
Networked devices are physical devices that are connected to each other and exchange data over a network.In the industrial Internet of Things, networked devices play a vital role.They connect factories, equipment, sensors and other components closely.The real-time sharing and efficient transmission of data are realized.
Cellular Modem is a kind of networking equipment specially used in industrial environment, which has powerful data processing and transmission capabilities.It is usually deployed at the factory site and is responsible for transmitting the data of the field devices to the remote server through the network.At the same time, it receives instructions from the server to realize remote monitoring and control of field equipment.
Modbus is a serial communication protocol, which is widely used in industrial automation. It adopts a master-slave mode,That is, a master device (usually the upper computer or server) communicates with multiple slave devices (usually the lower computer or field devices).Modbus protocol is simple, reliable and open, so it is widely used in various industrial automation systems and equipment.
Modbus protocol supports multiple transmission modes, including RTU (serial communication), ASCII (serial communication) and TCP/IP (Ethernet communication).In Cellular Modem, TCP/IP mode is usually used for data transmission to achieve high-speed and stable data communication.
Establish a connection: Cellular Modem, as a slave device, first needs to establish a TCP/IP connection with the remote server as the master device.This step is usually implemented through Socket programming, including monitoring the specified port, accepting connection requests and other operations.
Initialize the Modbus connection:Once the TCP/IP connection is established, the Cellular Modem sends a Modbus initialization request to the remote server.Include information such as device addresses, communication parameters, etc. After receiving the request, the remote server performs the corresponding initialization processing.
Data request and response:In Modbus communication,The master device acquires data from the slave device by sending a function code and a data request or sends a control instruction.Cellular Modem, as a slave device, receives a data request from a remote server.The corresponding data is read from the local device according to the function code and the data address in the request,And send that data to a remote server ov a TCP/IP connection.At the same time, the Cellular Modem also processes the control commands from the remote server and forwards the commands to the local device for execution.
Error handling and anomaly detection:Cellular Modem performs error handling and anomaly detection during Modbus communication.For example, when an invalid data request or data is received, the Cellular Modem may return an error code to the remote server,O that the server can process accordingly.In addition, the Cellular Modem monitors the stability of the TCP/IP connection,Immediate reconnection or exception handling occurs.
Closing the connection:The Cellular Modem actively closes the TCP/IP connection to the remote server when the data transfer and control tasks are completed.At the same time, it frees up local resources to prepare for the next communication.
CellularModbus transmission protocol of Modem involves connection establishment, Modbus connection initialization, data request and response, error handling and exception detection.Test and close the connection and other links.Through this process, Cellular Modem can achieve stable and reliable data transmission and control functions with remote servers.It provides strong support for the development of industrial Internet of Things.
Looking forward to the future, with the continuous development of Internet of Things technology and the improvement of industrial automation level.Cellular Modem will be used more and more widely.At the same time, with the continuous improvement and expansion of Modbus protocol, its application in the field of industrial automation will be more in-depth.We have reason to believe that under the combined promotion of Cellular Modem and Modbus protocols,The industrial Internet of Things will achieve more efficient, intelligent and sustainable development.
