Free Serial Port Terminal with Scripting

Free Serial Port Terminal Overview

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Free and simple Serial Port communication utility for Windows platform.

Free Serial Port Terminal is a freeware version of HHD Software Automated Serial Terminal that has long been developed as part of the famous Device Monitoring Studio project.

This product has been designed with a focus on extreme user-friendliness and the ability to automate all kinds of tasks. A "modular" approach has been applied to its internal architecture and visual layout.

In contrast to competing products (even paid and expensive ones), our free Com Port terminal provides you with a convenient window-based interface and allows you to run scripts in a basic version.

Basic Features

Free Serial Port Terminal supports all kinds of legacy and Plug-and-Play Com-ports, USB Com-ports created by majority of popular USB-to-serial adapters or USB-to-serial converter cables and software-based virtual serial ports.

It allows you to connect to a serial port device and send/receive data over the serial line in a variety of formats, including bytes, text characters/strings, non-ANSI/ASCII characters, and files. This communication tool supports transmission of hexadecimal, binary, float and double data sequences, as well as sending text data in virtually any encoding, including multibyte UNICODE UTF8, UTF-16.

Our free RS232 terminal allows you to open any number of serial ports simultaneously, supports standard and non-standard bit rates, data bits, stop bits, parity bits, software XON/XOFF, hardware flow control and custom flow control settings. It displays the states of modem and handshaking lines (CTS, DSR, CD, RI), allows you control RTS and DTR lines. For best usability, it automatically saves configuration parameters and communication port settings.

We are constantly improving our product and in the next version we also plan to add the ability to switch connection parameters without having to reopen the port. You'll be able to change baud rate, parity, databits, stopbits, flowcontrol parameters "on the fly".

Basic version of serial terminal allows you to execute both JavaScript and TypeScript. Therefore, you can automatically send data to the legacy and PnP serial ports with UART and RS232/422/485 serial interfaces using your custom scripts. Free Serial Port terminal API allows you to emulate serial applications and devices, control serial line data, signals and more.

Advanced features

Advanced Features

This is a Freemium serial port terminal, which means that it provides you with free basic communication and automation features, but some advanced features require payment. Some of these features are already available in the current version, and some are planned for future releases.

There is convenient Modbus Master and Modbus Slave simulator module, which is already available in the current version. This Modbus device emulation tool allows you to send both Modbus ASCII and Modbus RTU commands to the Modbus Master or Slave devices. It supports sending requests and responses, allows you to read/write registers and coils using the necessary functions and addresses. All of this functionality can be managed both manually from the GUI and using automation scripts. You can find this function extremely useful if you need to simulate the Modbus protocol, test Modbus devices, debug Modbus applications, etc.

Here are the features planned for next product verion:

Real-time logging and exporting of serial port data. Logs both text and raw binary data, all in a convenient and user-friendly format.
Detecting specific data sequences in the data stream transmitted over the serial interfaces. High-performance, instant data processing allows you to create real-time testing applications.
Serial protocol simulation and automatic data responding functionality. Define triggers, specify responses, control the process with GUI or scripts, create your own automatic serial protocol simulation tasks and more.

Download this rs232 terminal and start testing and debugging serial communication in seconds!

Usage Scenarios

It's probably the best free serial terminal for developers, You'll find it useful each time you need to:

debug serial port applications.
test RS-232, RS-422 and RS-485 hardware devices.
simulate serial communication protocols.
troubleshoot serial port communications.
create autometed test tasks for serial devices or applications.

It helps in analyzing RS232/RS422/RS485 communication protocols, reverse-engineering serial peripherals, communicating with Modbus devices, developing and debugging serial device drivers and more.

Download this free Com port terminal and start testing and debugging serial devices in seconds!

System Requirements and Tech Specs

Free Serial Terminal requires AMD or Intel x86/x64 compatible CPU, 2+ GB of RAM memory and 25MB of free disk space. It runs on both 32-bit and 64-bit Windows-based operating systems starting from Windows 7. Free Serial Port Terminal supports Windows 11, Windows 10 and Windows Server 2022.

Free Serial Port Terminal Advantages

Reliable. It's based on the proven technology of the award-winning parent product.
Friendly. It allows you to run automation scripts even in the basic version.
Flexible. It allows you to tune every aspect of the User Interface.
Compatible. It supports legacy, PnP, Usb-to-Serial and even virtual COM ports.
FREE. It costs nothing!