In the application of IIoT, serial communication, as a classic and widely used data exchange method, is crucial for the stability and reliability of the entire system. In order to ensure the smooth progress of serial communication and to detect and solve potential problems in a timely manner, it is particularly important to effectively monitor the serial communication data. This article will provide detailed guidance on how to monitor serial communication data from the perspective of a senior R&D engineer in the Industrial Internet of Things, providing professional guidance for those who need to develop networking applications.

1. What is the basis of serial port communication

Before discussing how to monitor serial communication data in depth, we first need to have a basic understanding of serial communication. Serial communication is a communication method that uses a serial interface for data transmission. It uses a single data line, or in some cases multiple lines, to transmit data according to a specific timing and protocol. In the industrial field, serial communication is often used to connect devices such as PLCs, sensors, and actuators to achieve data exchange and control between devices.

2. Purpose of monitoring serial port communication data

The main purposes of monitoring serial communication data are as follows:
Ensure data integrity: Through monitoring, errors in the data transmission process can be detected and corrected in a timely manner to ensure the integrity and accuracy of the data.
Performance analysis: Analyze performance indicators such as response time and throughput of serial communication, and evaluate the system's operational efficiency and stability.
Troubleshooting: When a system malfunction occurs, monitoring data can quickly pinpoint the problem, providing strong support for troubleshooting.
Security audit: Monitoring serial communication data can also be used for security audit to prevent security issues such as illegal access and data leakage.

3. Method for monitoring serial port communication data

3.1 Use serial port monitoring tools

There are many professional serial port monitoring tools available on the market, such as Serial Port Monitor, PortMon, and so on. These tools usually have the following functions:
Real-time capture: It can capture all communication data on the serial port in real time, including data sent and received.
Data analysis: Support data analysis of multiple protocols, such as Modbus, ASCII, HEX, etc., to facilitate user understanding and analysis of data.
Filtering and Searching: Provides data filtering and searching functions to help users quickly locate interesting data packages.
·Logging: Support for saving monitored data to files for subsequent analysis and audit.

3.2 Writing a custom monitoring program

For users with special needs, you can write a custom serial port monitoring program. This usually requires the use of serial port communication libraries in programming languages such as Python's pySerial and C#'s SerialPort, combined with multi-threading or asynchronous programming techniques to achieve real-time data capture and processing.
When writing a custom monitoring program, you need to pay attention to the following aspects:
Exception handling: Ensure that the program can properly handle various exceptions that may occur during serial communication, such as port occupation and data transmission interruption.
Performance optimization: Optimize the data processing logic and memory usage of the program to ensure stable performance under high load conditions.
User interaction: Provide a friendly user interface or logging function to facilitate users in viewing and analyzing monitoring data.

3.3 Combination with network monitoring tools

In some application scenarios, serial devices may access the network through devices such as serial servers. At this time, you can use network monitoring tools such as Wireshark and tcpdump to monitor serial port communication data. By capturing data packets on the network and analyzing their contents, it is possible to indirectly monitor serial communication data.

Precautions for monitoring serial port communication data
Comply with laws and regulations: When monitoring serial port communication data, it is necessary to comply with relevant laws and regulations and privacy policies to ensure that the legitimate rights and interests of others are not infringed upon.
Data security: Take necessary security measures to protect the monitored data from illegal access and leakage.
Performance impact: Monitoring serial port communication data may have a certain impact on system performance, such as increasing CPU usage and occupying network resources. It needs to be evaluated and adjusted based on actual conditions.
Continuous monitoring: For critical business scenarios, it is recommended to conduct continuous monitoring to ensure the stability and reliability of the system.

Monitoring serial communication data is an indispensable part of industrial IoT applications. Through reasonable monitoring strategies and methods, potential problems can be identified and resolved in a timely manner to ensure the stable operation of the system and the accurate transmission of data. This article introduces various monitoring methods such as using serial port monitoring tools, writing custom monitoring programs, and combining network monitoring tools, and provides corresponding considerations. We hope that these contents can provide valuable references and lessons for people who need to use network applications.