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Null Modem Emulator
Emulate virtual Null-modems

Null Modem Emulator is used to create compatible serial ports connected via virtual null modem. These virtual COM ports work in pairs, forming a virtual “bridge”: data sent by one application will be instantaneously received at another end of the pair by another application.

The ports created by this virtual null modem emulator appear to your operating system or any Windows application as standard hardware serial ports. In fact a virtual null modem emulator not only does not clutter your desk, but also works faster than a real null modem. The virtual COM driver can be included in your own software providing a way to create and configure virtual COM ports directly from your application (OEM license).

Virtual Serial Port Driver benefits

  • Any number of virtual COM ports

    With this null modem RS232 driver you can create almost unlimited number of virtual com ports and assign them any name, including the name of an existent serial port. Created ports are located in “ports” group in Device Manager so that they are visible and easily recognizable by the system. You can define which application can access a particular port, your real hardware serial ports remain free.
  • Real ports settings emulation

    These virtual com ports emulate all the serial port functionality, including Baud rate, data bits, parity bits, stop bits, etc. RS232 null modem driver uses advanced Windows kernel driver technology, which ensures WDM, WMI, Power Management, PnP, etc. support. This virtual com port driver emulates a serial line break and it is fully compatible with API COM and supports all Windows messages.
  • All signal lines support

    The virtual serial ports created with Virtual Serial Ports Driver emulate and support all standard hardware signal lines (DTR/DSR, RTS/CTS, RING, ERROR, DCD, etc.). Similar to the connection via real null modem cable, DTR of the local port is connected to DSR and DCD of the remote port, and RTS of the local port is connected to CTS of the remote port. Moreover, you can choose loopback pinout or customize it according to your hardware configuration.

Virtual Serial Port Driver Licenses

OEM License permits you to embed Virtual Serial Port Driver technology into your own software or hardware products. OEM license grants you the right for unlimited redistribution of Virtual Serial Port Driver as an integral part of your software. OEM license is a royalty-free one-time purchase.

OEM License

Virtual Serial Port Driver Inside Your App

Purchasing the OEM license you get:

  • OEM documentation on how to work with our driver directly
  • Example for creating a class which demonstrates the possibility to create the ports like in VSPD (visible and invisible ports)
  • vspdctl.DLL - wrapper for a driver for manipulations with virtual serial ports on a higher level
  • Supported IDEs

OEM For Developers
Sign up for the API evaluation program and integrate it into your product on: Windows, Mac, Linux, Android, ARM.

Source Code License

Ordering Source Code license for Virtual Serial Port Driver you receive all extensively commented programming source code of the driver (GUI sources are not included). In addition, we provide technical and information support by email, IMs and phone, and high-end consulting services. Our leading developers will help you implement Source codes and understand the advanced part of the product.

Site Licensing

Unlimited Site License grants you the right to install and utilize Virtual Serial Port Driver application with GUI on unlimited number of computers by all workers of your company worldwide. It is the ideal solution if your company has representation offices in the different parts of the world.

If you know the certain number of computers to be equipped with VSPD you may consider obtaining Limited Site License. The advantage of Site Licensing comparing to multiple Single licenses is one license key for all company computers.

Full features list

Create unlimited number of virtual serial ports with the help of virtual null modem emulator.
Emulate serial ports that are no different from real ports – the system will not distinguish between them.
Control virtual serial ports from your own application; VPSD comes along with Dynamic Link Library (for OEM License owners).
Make most of the fast connection between virtual ports. Virtual null modem cable transfers data at an average speed of ~ 5.5 Mb/sec.
Leave your hardware ports free – virtual null-model does not even require your system to have one.
Emulate ports only for the current session; RDP users can give the same name to ports in each session.
Update the list of ports automatically, this allows viewing ports created in other user sessions.
Create ports instantaneously, i.e. null-modem emulator allows to start working with virtual ports even before PnP manager detects them.
Emulate all parameters of real ports, including strict baudrate.
Delete ports at any time, even if they are being used by other apps.

What customers say

  • We are using VSPD for testing out Geographic Information System software connectivity with a virtual GPS (software simulation). The GPS emulator is simulating the output we normally receive from a GPS navigator.
    Bjørn Krangnes

Overall rating 4.9
based on 97 reviews

Let's get started

Virtual Serial Port Driver for Windows
Demo version limitations
• 14-day fully-functional trial
System Requirements
Windows (32-bit and 64-bit): XP/2003/2008/ Vista/7/8/10, Windows Server 2012, Windows Server 2016
Latest Update
Version 9.0.567 (5th Aug, 2017) Release notes