Serial Port Monitor is a professional software application that allows reading and recording serial data going through your computer’s serial ports. The program is a big help for those who develop and debug software and hardware solutions that use COM ports for serial data transfer.

RS232 Port Monitor comes with a slew of powerful features, including advanced filtering and search options, built-in terminal, convenient data visualizers, the ability to record serial communication data to a file, and more. The software has a streamlined and user-friendly interface and doesn’t require any programming skills.

There are Standard, Professional and Company editions of Serial Port Monitor.

Here’s why to choose RS232 Port Sniffer:

It logs COM port data and saves it for later analysis

Serial Port Monitor can sniff data transmitted over a serial port even when it is already used by another application. You can connect to any of the COM ports available in your system and capture its data in real time. This will help you identify problems that may appear during serial communication and prevent them.

All monitoring data, including serial input/output control codes (IOCTLs) with full details and parameters, can be forwarded to a specified file or copied to the clipboard. What’s more, you can save the whole monitoring session and load it next time you need it.

It’s able to monitor multiple ports within one session

There’s no need to start a new session for every port you are going to monitor. The software allows you to sniff data from several COM interfaces within one session. This means you’ll be able to track the communication of your serial app with multiple devices at a time. The data will be recorded using the first-in, first-out method and shown as a single log.

It offers five different data viewing modes

Serial Port Monitor has five visualizers to display monitoring data. Those are table, line, dump, terminal, and Modbus views. You can use one at a time or all of them simultaneously. Also, you can apply IPR filters if you want to track down only communication events of a particular type.

It can emulate sending data to a selected serial port

When using the software in terminal mode, you can emulate sending some special commands to the monitored port as though they were sent from a monitored application. This way you get the ability to check the reaction of the COM port and device connected to it. The data you forward can be in a string, binary, octal, decimal, hexadecimal, or mixed format.

It sniffs Modbus RTU and Modbus ASCII data

In case your devices communicate using the Modbus protocol, you can read and analyze their data flows as well. COM Port Monitor parses Modbus data and shows it in the corresponding view.

It allows comparing monitoring sessions

The software provides you with the great ability to compare your current monitoring session with the one you saved previously. The two sessions will be displayed in two adjustable windows so that you can easily see all the differences between them.

Serial Port Monitor full features list

Start/stop monitoring the serial port that is already opened by another application (available in Professional/Company Edition only)
Completely compatible with Windows 10 (both x32 and x 64)
Serial Port Monitor and all of its internal drivers are digitally signed
Any number of serial ports can be monitored simultaneously
Possibility to add several ports for monitoring in one session
Supports all COM-port types: standard on-board ports, extension board ports, software-based virtual COM ports, bluetooth serial ports, USB to SERIAL cradles, etc
Data transmission monitoring and logging
Advanced send dialog: easily send various types of data, apply aliases for faster typing and automation, send files and loop functions and commands, change serial port parameters on-the-fly (available in Professional/Company Edition only)
Real-time data capturing
Various monitoring visualizers: table view, line view, dump view, terminal view
Incoming and outgoing data streams logging
Redirected file can be either split into a bunch of files or can be limited to user-defined size
Possibility to export raw data to a file in Terminal view
Multi-colored commands display in table view
Any software/hardware that works with a serial port can be monitored
Intercept and record all serial input/output control codes (IOCTLs), tracking their full details and parameters
Customizable monitoring session logging (several timestamp formats, different scale of notation, customizable logging string length etc.)
Convenient and flexible monitoring session's management: saving and loading all monitored data, exporting and redirecting to file functions
Monitoring session exporting (HTML, ASCII text, UNICODE text, Exсel CSV) and automatic redirection to file (Serial Port Monitor will automatically append all monitored data to a file in real-time)
Supports copying all recorded data to clipboard
Supports adding data automatically before and after packet to be transmitted
Full duplex mode supported
Control lines status visualized
Unique stream filtering tools with presets
All baudrates supported
Flexible configuration: stopbits, flow control, parity control, data bits, highlighting, etc.
User-friendly flexible interface: the software is designed to provide easy access to serial ports, no programming skills are required
The “Comments” section in the Table view
Quick filters customization in the toolbar
A new data redirection file can be created when monitoring is inactive
The statistics in status bar from first to last highlighted IRP in the Table view. The IRPs in Table view now have the transcript hints from the Line view
Filter data by ports
The data that an application tried to write to port is displayed additionally to actually written data
The automatic scroll for the Terminal view can be disabled
Instead of overwriting the existing data in the file one can continue writing to it with the new command line option

Compare STANDARD and PRO/Company versions

# Feature Standard Pro / Company

Monitoring serial ports X √

which are already in use

Sending/receiving data to/from X √

any COM port (Advanced Send Dialog)

The possibility to change COM port X √

parameters from Advanced Send Dialog

Any serial port software/ hardware √ √

can be analyzed

Monitors any number of serial ports √ √

at once

6 Supports all COM-port types √ √

7 Intercepts all data read from/written √ √

to PC COM port

8 Built-in search √ √

9 4 types of customizable monitoring √ √

visualizers for viewing and logging data

Incoming and outgoing data streams √ √

logging

Tracing all serial input/output √ √

control codes

12 Copying all recorded data to clipboard √ √

13 Saving, loading and exporting all √ √

monitored data

14 Full duplex mode √ √

15 Unique stream filtering tools √ √

with presets

16 The software offers a free trial, which √ √

allows using it as a free serial port monitor

tool for 14 days

What our software is capable of

Throughout its long history, our software has helped a lot of people to solve a variety of tasks and problems of absolutely different kinds. And here are some of them:

Simple and reliable

I have tried a good number of serial sniffers, but most of them were stacked with the excessive features that only increased the cost of the tool, but did not directly influence its main purpose – conveniently collect serial data. After spending some time on research, I opted for Serial Port Monitor as the most optimal variant among other similar programs.

Gregory Williams, Programmable Logic Controller Programmer

Powerful Combination

As I decided for myself, there is no need to spend money on 2 separate pieces of software, when Serial Port Monitor perfectly combines them: a serial sniffer and a terminal emulator.

John Albarn, Electromedical Equipment Technician

Informative data

A sniffer that will not only collect all data but will also accessibly display it is essential during the development and debugging of the applications or hardware that work with serial ports. Serial Port Monitor’s data visualizers provide exactly that.

Richard Swanson, Software Developer

Serial debugging

We mainly use it for debugging serial commands (byte stream) coming from various sensors on one of our mobile robotics bases. We also use it for any kind of weird serial issue that we can't figure out. It's a great product though!

Dave Kush, CTO

FAQ about Serial Port Monitor

How can I monitor serial port traffic?

In order to read and analyze serial port data, you should start a serial monitoring session.

Here’s how you can do this using Serial Port Monitor:

Download the software and install it on your Windows PC;

Start the program and select Session > New session in the main menu;

In the window that will open, select the COM ports you would like to monitor;

Then, select the viewing mode for captured serial data. There are five data visualizers: Table, Dump, Line, Terminal and Modbus views;

Choose between the Start monitoring now and Start in new window options;

Check the boxes next to the events you want to capture – Create/Close, Read/Write, Device Control;

Click tart monitoring to activate your session.

How can I test a serial port?

With the help of a dedicated serial port scanner software, it’s possible to check whether a COM port is working. Designed for Windows, Serial Port Monitor provides a set of advanced features for serial port testing.

Here are just some of the app’s capabilities that will let you test your RS232 ports:
Starting a monitoring session;
Recording the incoming and outgoing serial data to a file;
Reproducing a monitoring session back to a serial port;
Comparing sessions.

Is it possible to monitor multiple COM ports simultaneously?

Serial Port Analyzer allows you to monitor as many serial ports at a time as you need. Simply add all COM interfaces you would like to monitor to your active monitoring session and read serial data coming in and out of them.

What customers say

Jon Kinne 4.8

Without the Serial Port Monitor from Eltima, I would not have been able to easily and quickly see the operation of the several serial ports carrying data to the navigation program...

Florin Vancea, a freelance software developer 4.8

With Serial Port Monitor by Eltima Software I have easily managed to develop a useful tool for logging and debugging and even embedded it into my own software.

David Coward 4.8

Serial Port Monitor allowed the analysis which would be impossible any other way. I was using your product to investigate the protocol which PC software uses to communicate with a mobile phone so I could get my SMS control device to do the same thing.

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