RS232 standard is popular in many scientific directions and is widely used for lab equipment, quality and process controllers, various sensors, measuring tools, etc. However, you may experience some issues while trying to analyze serial port activity. A number of aspects have to be taken into consideration: hardware and cabling, communication settings and protocols. To be able to perform COM monitor activities successfully and detect any issues with serial data, you'll need a reliable serial port sniffer with a comprehensive RS232 activity log.

1. Serial Port Monitor by Eltima Software

First on our list is Serial Port Analyzer - a high-quality COM port sniffer product that can log, display and help you analyze RS232/422/485 port activity in the system. Getting all the data from this useful app allows for quality application and driver development, as well as testing and debugging of COM port devices. No additional hardware is required for RS232 port Monitor solution by Eltima. There are Standard and Professional editions depending on your needs.

With RS232 Analyzer you can connect to ports that are already open and start monitoring at once. Data is captured in real-time and displayed conveniently. Data packets are easy to compare. You can record IOCTLs with all the details and parameters.

This COM port sniffer can monitor several ports at once so users can get the data on how apps interact with several serial devices within a session. The collected data can be viewed as table, line, dump or terminal, with sump view being able to show binary, ASCII data and port settings. Another great feature this serial port testing software offers is emulating data transmission to a serial device so you can see and analyze the reaction of a device to certain commands and data. You can send string, binary, octal, decimal, hexadecimal, or mixed data.

The popular Modbus RTU and Modbus ASCII protocols are fully supported with all essential filters for the most effective analysis.

Serial Port Analyzer is the most precise RS232 testing software thanks to the possibility to reproduce the monitoring session in order to review certain port behavior with the same parameters used in different conditions.

The software comes with a comprehensive help system and intuitive interface, which makes it fairly simple to use.

With free serial port monitoring you can connect to real or virtual COM port and monitor the transmitted data. Specify the textual content record to keep all intercepted records to for your analysis. RS232 Logger will show how many bytes are saved in the log file and all records logged from the serial port in a complete way.

Serial Port Monitor customer's feedback
When trying to build a custom dashboard for a third party Li-Ion Battery Management System based on Texas Instruments BQ76940 and Atmel 8-bit line of microcontrollers, the integrated circuit manufacturer provided a "brief" description of the communication protocol. This description wasn't enough or complete, so analyzing the protocol transmitted while using the manufacturer provided Windows based dashboard was a must. Eltima's Serial Port Monitor with the capability of "sniffing" open serial ports on Windows platform was the best tool to do the job. Now I can see in realtime the protocol flow and understand the documentation, saving me a lot of trial and error while programming. I'm very happy of having found this piece of software.

Eduardo Roldan (Linux Expert, DIYer, EV Enthusiast)

2. Advanced Serial Port Monitor

Advanced Serial Port Monitor is perfect for performing serial monitoring of the peripheral devices connected to your computer. The free Serial Port Logger lets you connect with up to 255 physical and virtual serial ports and save data transmission information to a file. Analysis of your serial traffic can be done at any time by accessing the saved data.

COM port data logging

This application is easy to use RS232 monitoring tool with a user-friendly interface. Simply choose the COM port you want to monitor and specify its parameters, select a file to store monitoring results, and click the “Start” button.

Collecting real-time serial data

As soon as you connect a serial device to a computer you can begin to monitor its data flow. Advanced Serial Port Monitor allows you to study the details of serial traffic and ports when used with scanners, meters, and any other type of device that connects to your machine through a COM interface.

3. Free Serial Protocol Analyzer by HDD Software

Another software solution, without any hardware needed. Free Serial Port Monitor can intercept, display and analyze data exchange between a device and a serial application. Also a useful solution for software, device driver or serial hardware development that helps you test, debug, and optimize your product. It will dig into data flows and protocols and display everything in a comprehensive way.

With this program, you’ll be able to capture data and serial input/output control codes (IOCTLs) going through a COM port.

Free Serial Protocol Analyzer provides users working with COM ports with a full set of information — the app allows formatting data into different kinds of output. What’s more, it offers emulation of data sending on behalf of a monitored app. This option will clearly help you better check the reaction of a COM port to some particular data.

What is also convenient is that the software allows searching for a text in a Data View, Request View, and Console View. Plus, it’s possible to change the way the hex data displayed in Request View and Data View.

4. SerialMon

SerialMon is a free RS232 port analyzer for Windows that takes up little space. It can monitor serial port communication through software or with a simple hardware solution. Supports ABB RP570, ABB SPA-bus and NMEA 0183 protocols.

5. Portmon for Windows

Portmon can monitor and display all serial port activity in a system. Also a good tool for tracking down possible issues with apps or devices configurations and analyzing serial port usage by the apps. This solution offers remote monitoring. You can monitor many remote computers at the same time. Multiple filters help you see the data conveniently and analyze it faster. This COM monitor can export captured data to a file like the previously reviewed solutions.

Portmon for Windows
Thank you for reading our top serial monitor tools selection. Whatever you are working on, choose a reliable and best performing piece of software to achieve the most satisfying results. To find out the most comprehensive solution for your needs, read the overview of Serial Port Monitor utilities.