List of
10 Serial Port Monitor software for Windows in your budget range

Free Serial Port Monitor

This RS232 Data Logger is a free, open-source application for monitoring serial interface activity.

Pros:

• simple interface that allows you to quickly start monitoring your ports;
• monitoring your system’s RS-232 communication in real and virtual environments;
• save captured data from multiple ports directly to a file for later analysis and enable or disable monitoring on-the-fly;
• since it is an open-source project you can study the code to learn about serial programming;
• run on all Windows versions from Windows 98 through the latest version of Windows 10 (32-bit and 64-bit).

Cons:

• ability to save data in a text file only.

by Anonymous:
64-bit+virtual environment. Serial port is shareable!. Haven't found any alternatives for the 64-bit environment. This tool allows to work with virtual machine and this is really helpful for my work! Pros: virtual machine. 64-bit environment (en.softonic.com)

SerialMon:

SerialMon is also freeware but is not open-source.

Pros:

• SerialMon is very lightweight so will not take up much room on your system;
• can be used as software and with cabling attached to the monitored device;
• it serves as a protocol analyzer for the ABB RP570, ABB SPA-bus, and NMEA 0183.

Cons:

• you can use this tool strictly as software or with simple monitoring hardware;
• this software is free to use but the developers request donations to support their efforts;
• the last update to the program was in 2013 (cannot be considered reliable for use with Windows 10);
• useful for sniffing COM ports on older versions of Windows (Windows 2000/Windows XP/ Windows 2003 Server/Windows Vista).

by shantanu75:
I had used the trial version of SerialMon for one my project 6 months back, that's the reason I suggested you. As it's easy to log serial data using SerialMon that using CRO or LA. (www.xilinx.com)

Free Serial Analyzer:

You can use this freeware to monitor COM port traffic employing the RS232/RS485/RS422 protocols.

Pros:

• you can display read/write data in separate windows and view monitored packets in table form;
• filtering functions enable you to control which data packets are observed;
• you can monitor serial ports on a local machine or remotely across the network;
• the software is designed to be run on Windows machines and supports all versions from Windows XP through Windows 10/x64 bit.

Cons:

• the free version of this application limits you to five monitoring sessions per day with the maximum time per session set at 20 minutes;
• grace period 4 day.

Portmon for Windows

Portmon is another free serial port monitor for Windows OS.

Pros:

• it allows you to perform remote monitoring, log data to a file, and make use of powerful filtering capabilities;
• the software includes an online help file that makes the tool more user-friendly;
• monitoring parallel ports as well as serial activity.

Cons:

• the last update was on January 12, 2012;
• you will only be able to use this utility on systems running Windows NT 4.0, Windows 2000, XP, Server 2003, Windows 95 and Windows 98.

by tomekajja
...Many thanks to you all. I can now send and receive data to the device via USB. Portmon is a great tool to check for serial issues... (www.microchip.com)

SourceForge Serial Port Monitor

SourceForge is an open-source community resource and Serial Port Monitor is one of the applications that it supports.

Pros:

• this tool resides in your Windows notification tray and notifies you when a device is added or removed;
• it is a simple tool that performs a single function to help you track the devices attached to your system;
• this freeware was last updated in late 2018 and supports Windows 10.

Cons:

• This software just shows the COM ports that are plugged into the computer. Actually, it doesn’t monitor the traffic passing through.

Serial Port Monitor by Electronic Team

This high-quality application delivers a full-featured and comprehensive tool for monitoring COM port traffic. Serial Port Monitor is a solution for discovering and breaking down problems that may occur during the test and optimization COM port devices' performance and more.

Pros:

• the software including the ability to sniff multiple ports simultaneously;
• emulate data transmission to test serial devices and applications;
• the app can monitor ports that are already opened and used by another application;
• has the ability to present captured data in multiple views and formats;
• in addition to supporting the standard RS232/422/485 serial protocols, Modbus RTU and Modbus ASCII communications can also be monitored and decoded with this flexible app;
• this tool provides session playback feature;
• it supports all Windows versions from XP to the latest Windows 10;
• supports all COM-port types: standard on-board ports, extension board ports, software-based virtual COM ports, Bluetooth serial ports, etc.

Other features of this serial port monitor are that the Bit Rate, Character Width, Parity and Stop Bits change serial port parameters on-the-fly.

You can download Serial Port Monitor for a fully-functional 14-day free trial. The standard version of the software costs $99.95 and the popular Pro version is $199.95.

by Rew:
I’ve been using this tool for a long time, and it is really powerful and easy to use. It provides a convenient way to monitor and analyze serial port activity. That’s exactly what I need. Thanks! (www.colormango.com)

Serial Monitor by HHD Software

Serial Monitor is the paid cousin of the aforementioned Free Serial Analyzer.

Pros:

• the features of this tool allow you to monitor, save, and analyze all serial interface activity;
• the software features a configurable user-interface to facilitate its use;
• multiple ports can be monitored at one time;
• the app supports custom defined serial protocols;
• it supports all Windows versions from XP to Windows 10.

Cons:

• the standard license doesn't provide MODBUS protocol commands.

You can try the application for 14 days risk-free. Purchasing a standard license costs $64.99 with the Pro version going for $149.99, the Ultimate version would cost $199.99.

Advanced Serial Port Monitor

Here is a flexible serial monitor that allows you to monitor serial traffic as well as sending and receiving data from your COM ports.

Pros:

• useful for diagnosing problems with external serial devices;
• data can be displayed in HEX or ASCII characters and you can log files for later analysis;
• a built-in scripting engine enables you to execute commands through plugins;
• the app can run on all Windows versions.

Cons:

• the program has system requirements that run with one free serial port;
• it does not decode Modbus RTU and ASCII.

The trial version is available but is limited to 30 minutes of use before requiring a license to continue. You can get a one year license for $19 with the standard product costing $60. A professional version is also available for $165 and comes bundled with additional software.

Serial Port Monitor by Awavo

Awavo COM Port Monitor lets you display, log and analyze RS232/422/485 serial communication data.

Pros:

• this application displays data that is sent and received through your system’s COM ports and timestamps the data transmission;
• useful for sending data to specific ports based on defined conditions or periodically on a timed basis;
• filters allow you to control the flow of data so only pertinent information is displayed
• COM Port Monitor supports Windows 10/8/7/Vista/XP.

You can test drive this software for free for 14 days and the full product costs $99.95.

RS232 Analyzer by CommFront

The last product of professional RS-232 monitoring software. It is an easy to use program with many advanced features.

Pros:

• it can be used to monitor, analyze, and control serial port activities and can display data in numerous formats;
• you can configure the application with programmable buttons, automated responses, and macros;
• All major Windows versions through Windows 10 are supported by this flexible software tool.

A Limited version is available for free with no time limitations. A single computer license of the full package costs $79.95. Multi-license would cost $279.95.