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A virtual serial port is a serial communication endpoint that software can access through a COM-style interface, even when there is no traditional serial connector on the computer. It may be created entirely in software, provided by a USB-to-serial adapter, or presented to a virtual machine. The word “virtual” describes the interface applications see; it does not tell you what the port connects to.
What “virtual serial port” means
A serial port lets software exchange data with another endpoint using serial communication. A virtual serial port presents that endpoint through an operating-system or application interface such as a COM port. Depending on the implementation, the endpoint may have no physical hardware behind it, may connect through a USB bridge to an external device, or may exist inside a virtual machine.
Microchip describes the USB-bridge case as a “virtual communications port” provided by a general-purpose USB serial bridge between a host PC and a target device (Microchip, “3.1.1 Virtual COM Port”). So a COM-style name alone does not establish whether a port is software-only or hardware-backed.
Three common kinds of virtual serial port
Software-created port pair
Virtual serial port software can create two linked COM-style endpoints on one computer. One serial application opens one endpoint and another application opens the other; data written to one can be read from its paired endpoint. The pair generally emulates a null-modem connection, so a physical null-modem cable is not required. Supported port names, signaling behavior, and compatibility depend on the software (Virtual Serial Port Kit product overview).
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- !!Please NOTE: this is MALE RS232 to DB9 SERIAL CABLE ,Not VGA!!!It is 9 pin, NOT 15 pin!! Look carefully of the Pin is match with your device. Before ordering , please confirm the interface gender is waht you need. After receiving ,please read user manual /instruction at first and download the Driver at first from FT232 Official website or Cisco website . Customer service always online.
- Wide range of applications: USB to RS232 DB9 male serial adapter can work with your Windows (10 / 8.1 / 8 / 7 / Vista / XP), MAC or Linux system and other platforms. USB adapter is designed to connect to serial devices, such as serial modem with DB9, ISDN terminal adapter, digital camera, label writer, palm computer, barcode scanner, PDA, cash register, CNC, PLC controller, tax printer, POS, bar code scanner, label printer, etc
- High quality: ftdi usb serial,the latest ftdi chip set ensures more reliable and faster operation. USB 2.0 to RS232 male DB9 console cable will support 1Mbps date transfer rate.
- Most convenient: rs232 to usb simple installation, plug and play, COM port creation, baud rate can be changed to the required settings. USB power supply - no external power supply required.
- Exquisite design: usb-to-serial,Gold Plated USB RS232 connector and PVC cable ensure high performance and extra durability. Powered by USB port, this USB to DB9 series RS232 adapter cable is designed to fit easily into your handbag.
USB serial bridge
A USB-to-serial adapter connects the computer to an external serial device. The adapter and its driver expose a COM-style interface to host software, while the adapter provides the physical connection to the target. Citrix documentation also describes USB devices functioning as virtual COM ports accessible in a manner similar to physical serial ports (Citrix, “Serial ports,” Virtual Apps and Desktops 2607 LTSR).
This is the kind of virtual port you need when connecting a computer to serial hardware. The correct adapter depends on the target device’s connector, electrical signaling, and operating-system support. A USB adapter is not needed for a software-only pair.
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- [ USB to RS-232 Serial Adapter ] : 5ft Cable Length - Easily connect legacy DB-9 serial devices to modern USB-equipped computers. Uses include industrial, lab, and point-of-sale applications.
- [ Easy Testing ] : Built-in signal tester features full LED indicators with dual-color display for quick and easy testing of RS-232 host-to-device connections.
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Virtual-machine serial device
Virtualization software can present a serial device to a guest operating system. In the Oracle VM VirtualBox 6.0 manual, an enabled guest serial port can appear as a standard 16550A-compatible UART and can be attached to a host pipe or TCP endpoint. Those details apply to that documented VirtualBox version; other virtualization products may offer different attachment options (Oracle VM VirtualBox 6.0 User Manual, “3.10. Serial Ports”).
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1Clear out junk files and repair common Windows errors2Fix the driver behind crashes, sound loss and screen glitches3Repair Windows errors before they cause bigger problemsWhich type should you use?
| Your goal | Appropriate type | What it connects |
|---|---|---|
| Exchange serial data between two applications on the same computer | Software-created virtual pair | One application to the other through linked endpoints; no external serial hardware is inherently required |
| Connect a computer to an external serial device | USB serial bridge | Host computer, adapter, and physical serial target |
| Give a guest operating system a serial interface | Virtual-machine serial device | Guest port to an attachment such as a host resource or network endpoint, depending on the virtualization software |
These options are not interchangeable. Choose based on the endpoint you need to reach, whether physical hardware is involved, where the port must appear, and what driver or signaling support the connection requires.
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- Serial adapter allows a serial device to be connected to a USB computer
- Plug and play convenience:DB9 serial port is seen as a COM port by your computer, and is available for use by any program that accesses COM ports
- No need for an external power adapter:draws power directly from your computer via the USB connection
- DB9 serial port supports data transfer rates up to 230 Kbps:twice the speed of a standard built in serial port
- LED shows adapter status and data activity at a glance
Why a virtual port may not behave like a physical port
“Virtual” does not guarantee identical hardware behavior. Port naming, supported control lines, driver requirements, and the destination for transmitted data vary by implementation. A software pair links applications; a USB bridge relies on its adapter and driver; a virtual-machine port depends on the guest configuration and its chosen attachment.
Control-line behavior can matter in board-specific setups. For example, Nordic Semiconductor’s nRF52840 DK documentation says terminal software must send DTR to configure the UART interface MCU pins (Nordic Semiconductor, nRF52840 DK “Virtual serial port”). A port appearing in a device list therefore does not, by itself, confirm that the target is connected or that the required signaling is active.
Quick Recap
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- Gold Plated USB 2.0 to RS232 Female DB9 Serial Cable connects serial DB9 (9 PIN) devices such as modems to standard computer USB ports, supporting up to 1Mbps data transfer rate. [ IMPORTANT NOTE ]: This USB to RS232 adapter features a female RS232 connector, NOT male — please confirm your device’s serial port type before purchase
- Adopted with latest Prolific PL2303 chipset, this USB to RS232 adapter supports Windows 11/10/8.1/8/7, Linux and Mac OS. Windows 11/10/8.1/8/7 is plug-and-play and will be automatically identified as COM port. Windows built-in drivers match most USB-to-serial chips; it will automatically download and install the matched driver under network environment. For offline Windows, Mac OS and most Linux systems, please download and install the official driver from CableCreation official website. Ubuntu Linux supports plug and play without driver installation
- Widely compatible with modems, ISDN terminal adapters, digital cameras, label writers, palm PCs, PDAs, cash registers, CNC, PLC controllers, tax printers, POS machines, barcode scanners, and other devices with standard DB9 serial ports. Please be noted this USB to RS232 female DB9 serial converter cable is NOT compatible with cutting plotter and SCM equipment. Kindly confirm your device interface and model before placing an order
- Features tinned copper conductor and triple shielding to ensure stable and high-quality data transmission. USB bus-powered design requires no external power adapter. If your computer cannot recognize the cable normally, please match it with a null modem adapter for normal use
- CableCreation provides 24-month warranty and lifetime professional customer service. This 6.6ft USB 2.0 to RS232 Female DB9 serial converter cable follows standard pin definition, suitable for the device requiring female RS232 interface. If you encounter any problems of driver installation or device compatibility, please contact our customer service at any time, and we will assist you within 24 hours
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- √USB to 9-pin serial cable Product features: easy installation, no external power supply, and physical drive required
- √Applicable scope: This product can easily realize the conversion between the USB interface of the computer and the universal serial port, providing a fast channel for the computer without a serial port, and using this product is equivalent to turning the traditional serial port device into a plug-and-play USB device.
- √ Supports various models of MCU, MCU STC download, LED screen control card, MODEM, and ISDN terminal adapter communication is suitable for computers or notebooks with USB ports.
- √Application platform: Support USB1.0/1.1 specification, compatible with USB2.0 specification, support full-speed transfer mode 12MBPS, support Win98, 98SE, Me, 2000, XP, Mac OS8.6, vista, win7-32, 64-bit.
- √Installation Instructions: 1. Run the driver CH340.EXE file to install 2. Connect the USB serial cable to the USB interface of the computer, and automatically install the driver 3. After the installation is successful, the COM port appears in the device manager
What to check when looking for a COM port
- Identify the implementation: Determine whether you configured a software pair, connected a USB serial adapter, or enabled a guest serial device.
- Check where it should appear: A host-visible USB bridge and a guest-visible virtual-machine port may appear in different operating-system environments. A software-created pair depends on the port names configured in its software.
- Confirm the connection and support: For an adapter, check its driver and compatibility with the operating system and target’s electrical interface. For a VM, check the guest port and its attachment. For a software pair, confirm both endpoints and the applications’ settings.
- Check signaling requirements: Some devices require control-line behavior such as DTR; consult the specific device and software documentation rather than assuming all virtual ports handle it the same way.
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