FREE Serial Port Monitor
Record COM port activity into a text file

FREE Serial Port Monitor is a COM port software to record all serial communication data into a text file. It easily collects data from a serial port device and saves this precious information into a new text file or continues from previous session.


FREE COM Port Monitor can log up to 256 serial ports at the same time. Serial Port Monitor is an absolutely FREE, open source application, which means you can freely use it, study, change and improve

Advanced Serial Port Monitor


Serial Port Monitor is a highly-functional and friendly utility that works with RS232/RS422/RS485 ports and allows you to save a lot of your time while developing and testing serial applications and hardware. It offers the full set of advanced port monitoring features, including a built-in terminal, unique data filtering options, convenient data viewing modes, session playback capability, and more.


With RS232 Data Logger you can:


Log serial COM port and track serial dataflow changes


FREE Serial Port Monitor has a simple interface, so to begin serial logging you just need to select the serial port, choose where to file serial communication data, define RS232 port's parameters and click "start". Logs in the text file will represent all details about serial port communications and RS232 dataflow.


Test RS232 communication between serial port devices and applications


FREE Serial Port Monitor can be installed and used under Virtual Machines, like VMWare or Virtual PC. Such functionality can be successfully used for testing. Our serial port logger is great for learning purposes, too.


Change COM port parameters remotely


Using the Telnet protocol (RFC 2217), the server and client can communicate and exchange configuration details. They can alert the local host if changes are made to the COM port setting or their line states.

It traces serial port state in real-time and collects precise data about real RS232 connection and serial dataflow exchange in your system. This gives real-life examples of how connection between any serial COM port and applications establishes and how it develops. With FREE Serial Port Monitor it's simple to see and learn how serial ports work!


Full features list:


  • redirect incoming data stream into a text file form any number of serial ports simultaneously
  • select the file to redirect incoming data to for each port
  • real-time counter of the received and stored bytes
  • collect data from the real serial ports as well as from virtual ones
  • disable/enable logging on-the-fly
  • append incoming data to already existing file
  • specify serial port connection parameters (baudrate, parity, stop bits, flow control, databits)
  • source code is provided (MFC/C++ VC7.1)
  • works under Virtual Machines

Supported operating systems:


  • Windows 10 (32-bit and 64-bit)
  • Windows Server 2012
  • Windows 8 (32-bit and 64-bit)
  • Windows 7 (32-bit and 64-bit)
  • Windows 2008 (32-bit and 64-bit)
  • Windows 2003 (32-bit and 64-bit)
  • Windows Vista (32-bit and 64-bit)
  • Windows XP (32-bit and 64-bit)
  • Windows 2000
  • Windows NT 4.x
  • Windows Me
  • Windows 98