HW Virtual Serial Port

HW Virtual Serial Port (HW VSP) is a specialized freeware utility designed primarily to redirect serial data over a TCP/IP network, making a remote network-connected device appear as a local COM port. When comparing it to alternative software, the choice depends on whether you need Serial-over-Ethernet redirection, local port pairing (null-modem emulation), or port splitting/multiplexing.

Choosing the right tool depends on your network architecture, budget, and specific software use case. Core Comparison Matrix Primary Use Case Key Strength Notable Limitation HW VSP3 Single Serial over TCP/IP (Network) Runs as Windows NT Service Only creates 1 virtual port com0com Local Port Pairing (Null-Modem) Open-Source Excellent for local app-to-app testing Complex installation on modern Windows Eterlogic VSPE Port Splitting & Multiplexing Paid (Free 32-bit) Allows multiple apps to read 1 port 64-bit version requires a license Electronic Team Serial to Ethernet Connector Enterprise Serial over Network Paid Commercial High-speed, multi-port, multi-platform Expensive licensing HW Virtual Serial Port (HW VSP) Overview

Developed by HW GROUP, HW VSP3 is the go-to tool if your serial device is connected to an Ethernet serial server, a Wi-Fi gateway, or an IP relay somewhere on your local network or the internet.

The Pros: The single-port version is completely free, highly stable, and runs seamlessly in the background as a Windows NT service (ideal for servers). It supports RFC 2217, which allows your local application to change the remote hardware’s baud rate and parity settings on the fly.

The Cons: The free version is strictly limited to creating one single virtual COM port. If you need to manage multiple ports simultaneously, you must upgrade to their commercial “Multi” version or purchase proprietary HW Group hardware. Key Alternatives by Use Case 1. For Local App-to-App Communication: com0com

If you do not care about networking and simply want to connect two different software programs on the same computer (e.g., connecting a GPS simulator to a navigation program), you need a virtual null-modem emulator.

How it compares: Unlike HW VSP, com0com creates virtual port pairs (like COM5 ↔left-right arrow

COM6). Anything written to COM5 is immediately received by COM6.

The Catch: It is open-source but notoriously difficult to install on newer versions of Windows (like Windows 11) because of driver-signing enforcement.

2. For Sharing One Hardware Port: VSPE (Virtual Serial Ports Emulator)