Plugable USB to RS-232 DB9 Serial Adapter (Prolific PL2303HX Chipset)
List Price : $18.95
Amazon Rating : (2174 Reviews)
- USB TO RS232 SERIAL—Connect legacy DB-9 serial communications devices to a modern computer with USB
- LEGACY SUPPORT—Add a 9-pin DB9 RS-232 serial port to any modern computer, replaces built-in or PCIe serial adapters, recommended for use with a serial cable or NULL modem cable
- FLEXIBLE—Programmable baud rate from 75 bits per second to 128,000 bits per second. Plug-and-play creation of a COM port. Powered by USB; no external power needed
- COMPATIBLE—Genuine Prolific PL-2303HXD Chipset for widest possible compatibility with Windows (11, 10, 8.x, 7, Vista, and XP), Mac, Linux, and other platforms
- 2 YEAR WARRANTY—We love our Plugable products, and hope you will too. All of our products are backed with a 2-year limited parts and labor warranty as well as Seattle-based email support
Easily add an RS-232 9-pin serial port to any computer with our PL2303-DB9 USB to Serial Adapter!
This adapter will let you connect older serial devices to modern computers, for terminal services, data transferring, remote control, and programming. Supports baud rates from 75bps to 12Mbps, multiple stop bit and parity types.
Connect legacy RS-232 serial devices to any modern computer
Plugable's USB to Serial Adapter features Prolific's PL-2303HX Rev D chip for the best combination of support and performance with a wide range of RS-232 serial devices. Drivers are built-into Windows 11, 10, 8.x, 7, and most Linux distributions, drivers are available for Windows XP, Vista, and macOS.
Connect legacy RS-232 serial devices to any modern computer
This adapter replaces a legacy built-in or PCI serial port and features a fixed male port with screw in connection. For connecting devices that also have a male connector an inexpensive DB9 coupler or standard serial cable can be purchased separately.
Works with devices with RS-232 serial ports such as other PCs with RS-232 ports, Bluetooth serial adapters, telescopes, amateur radio gear, GPS receivers, routers, firewalls, modems, plotters, embedded character displays, scan tools, sonar units, embedded boards and many others. Specific devices include: Garmin eTrex GPS, Seiko Label Printer, iRobot Create, Cisco products with serial consoles, US Robotics Modems, NexStar telescopes, Equus Scan Tools, Uniden Hand Held Scanners, etc. Works with software like: HyperTerminal, TeraTerm, WinDBG, all open source serial software on Linux, etc.
We use only genuine Prolific serial chipsets in our adapter. Some inexpensive serial adapters use cloned Prolific serial chipsets that will not work with the latest Prolific drivers, both those available for download and the drivers embedded in Windows. Because we only use genuine Prolific chips, our adapter is always compatible with the latest drivers from Prolific.
In The Box
|Item and Quantity||Item Notes|
|1x USB to RS232 serial adapter|
|1x Quick Start Guide|
|1x Driver CD||Latest drivers are provided on Plugable's website or through Windows Update.|
|Port||Placement||Power Host / Device||Connection Type||Notes||Voltage||Amperage||Wattage|
|USB-A to Host||Cable End||Device||Bus Powered (No Power Adapter)||5.0V||500mA||2.5W|
Connection To Host
|Port||Placement||Version and Link Rate||Features|
|1x USB-A||USB 1.1 (12Mbps)|
|Port Type (Side 1)||Cable Specification||Port Type (Side 2)||Cable Length||External Power for Cable|
|1x Male USB-A||USB 1.1 (12Mbps)||1x Male RS-232 DB9 Serial||0.6m/2.0ft||No|
Compatible Operating Systems
- Microsoft Windows 10, 8.1, 7, Vista, and XP
- Microsoft Windows Server 2000SP4, 2003, 2008, 2012, 2016, and Windows Server 2019
- Apple macOS 10.9 through macOS 10.15 using the binary driver
- Apple macOS 10.15.5 through macOS 11 using built-in drivers embedded in the operating system
- Linux Kernel 2.4.31 (May 2005) and newer include support for this serial adapter
Incompatible Operating Systems and Host Computers
- Microsoft Surface Pro X (Microsoft SQ1 ARM based processor ) no driver support and disconnection issues on test system.
- Apple iPad and iPhone devices have no support for this serial adapter
- Android may have limited support on a device by device basis for this serial adapter
- macOS versions prevous to 10.9 required 3rd party software to work with this serial adapter
Identifying Your Adapter
As of 2021 we have updated our PL2303-DB9 USB to RS232 Adapter to replace the discontinued Prolific PL2303-HXD chispet with a new PL2303-GT chispet. This new chipset is feature compatible with the original PL2303-HXD chipset but may require installing drivers to be properly detected on Windows 7, 8, 8.1, macOS, and Linux kernels up to 5.5.
The original Plugable PL2303-DB9 adapter with Prolific PL2303-HXD chipset has a blue plastic case, while the updated adapter with the Prolific PL2303-GT chipset has a brown plastic case for ease of identification.
- Download the driver v220.127.116.11 and save the .zip file to the Desktop or Download folders
- Connect the USB to Serial adapter to the computer
- Open the Device Manager (right-click) on the Start Menu and select "Device Manager"
- Expand the "Ports (COM & LPT)" section
- Right-click on the entry "Please install corresponding PL2303 driver to support WIndows 11 and further OS." and select "Uninstall device"
- Check the box to delete the drivers and then click on the "Uninstall" button to proceed
- When completed, right-click on any entry in the Device Manager and select "Scan for hardware changes"
- Repeat steps 5-7 until the "Ports (COM & LPT)" section shows "USB-Serial Controller D" with an error icon to the left
- Now extract the contents of the zip file downloaded in step #1, navigate into the extracted files and double-click on "PL23XX-M_LogoDriver_Setup_40100_20230307.exe" to start the installtion process
- Follow the on screen prompts to install the Prolific serial drivers and when completed the serial adapter should be assigned a COM port number.
- Make sure the PC or tablet has an open internet connection.
- Insert the USB Serial Adapter into a USB port on your computer.
- Windows Update will install the most recent drivers automatically.
If Windows does not automatically install the drivers for this serial adapter:
- Open the Start menu and select the "Settings" cog icon
- Select "Update & Security"
- Select the "Check for updates" button and let Windows check for available updates
- Select the "View optional updates" link
- Expand the "Driver updates" section and check the box for the "Prolific - Ports" driver
- Select the "Download and install" button to complete the driver installation
The Serial adapter should now be detected in the Device Manager, showing the COM port number in the "Ports (COM & LPT)" section.
- Drivers for Windows 8.1, 7, Vista and XP are available through our Plugable Website here and selecting the "Serial Adapter" section
PL2303-HXD - Blue
- macOS 10.14.6 and newer include the Prolific Serial Drivers
- Drivers for macOS 10.9 through 10.14 our Plugable Website here and selecting the "Serial Adapter" section
- **We recommend using the drivers built-into macOS whenever possible**
PL2303-GT - Brown
- TBD: Detailed installation guide for macOS ( similar to DisplayLink/ASIX )
PL2303-HXD - Blue Adapter: Open source drivers are included in Linux kernels 2.4.31 and later. They support the Prolific 2303 chipset, and recognize the Plugable adapter.
PL2303-GT - Brown Adapter: Open source drivers are included in Linux kernel 5.5 and later. For older kernel versions the drivers can be downloaded directly from Prolific's website here.
Change COM port settings
- Open the Device Manager
- Windows 11, 10, and 8.1: Right-click on the Start menu and select "Device Manager" from the popup menu
- Windows 7: Left-click on the Start menu > Control Panel > System and Security. Then select the "Device Manager" link under "System"
- Expand the section "Ports (COM & LPT)"
- Right-click on "Prolific USB-to-Serial COMM Port (COM#)" and select "Properties" from the dropdown menu
- Click on the "Port Settings" tab, then click on the "Advanced" button
- Select your preferred COM port # from the "COM Port Number" drop down menu, some Ports may be unavailable if they are already in use by another device
- Click "OK" to save settings, then close and reopen the Device Manager and expand the "Ports (COM & LPT)" to verify the new COM port number is displayed
Connecting Serial Devices
Following the installation instructions provided by the manufacturer of your serial devices, install any needed software or drivers. Connect the serial device to the adapter, and make any needed settings, such as COM port, baud rate, flow control, stop bits, etc.
For more detailed information, see the User's Manual provided on the included CD-ROM.
Questions? We're here to help! Please reach out to us at email@example.com
Note: macOS 10.13 High Sierra has introduced additional security to Gatekeeper requiring extra steps to enable the driver, we have documented the procedure in our Knowledge Base.
|Platform||Important Notes||Date||Version and Download|
|Windows 11, 10, 8.x, and 7||
Drivers will typically install automatically through Windows Update
|Windows XP and Above||2018||1.20.0|
|macOS 10.9 to 10.15.x||
MacOS 10.13 High Sierra has introduced additional security to Gatekeeper requiring extra steps to enable the driver, we have documented the procedure in our Knowledge Base
|December 4, 2019||2.0.0|
|Linux Kernel 2.6.11 and Above||
Support for the adapter is built into Linux kernels above version 2.6.11.
Please visit the Prolific PL2303 driver download page for all other operating system options. Login as guest with the password guest and choose USB Serial/Parallel under USB Smart I/O Controllers.
Filter Help Articles and Frequent Questions by Category
Well how about that, it looks like we don't have any articles matching your filters! Try removing one of your choices or clear the filters to show all articles.
You can always contact support if you need help too!
How to change the COM port for a USB Serial adapter on Windows 7, 8, 8.1, and 10
Originally authored by: Bernie Thompson, July 4, 2011
Start by going to the Device Manager. Once there do the following: Expand the Ports ‘(COM& LPT)’
You should be looking at something like this:
As you can see Windows has set the port to COM10. However many legacy applications expect the port to be between 1-4. Let’s change that:Right click on the device and click on ‘Properties’.
Click on ‘Port Settings’. Then click on ‘Advanced…’.
Once you’re in ‘Advanced Settings for COM10’ on the bottom you can see the ‘COM Port Number: COM10’. Click on that to change it to the lowest possible number (between 1-4).
Then click ‘OK’ on all open Property Windows. Now the device should look like this:
Installing the Plugable USB to RS-232 DB9 Serial Adapter on Windows 7
Originally authored by: Bernie Thompson, July 5, 2011
Windows 7 will detect and pop up a wizard to install drivers when our Plugable USB to Serial adapter is plugged in, but it’s also easy (as essential on other operating systems) to install the driver software first. Here’s how.
Get the driver from: https://plugable.com/drivers/prolific/
You’ll want to download the driver and unzip it anywhere on your desktop. Once you have, double click on it to start the installation.
The installation is relatively simple and no questions are asked. When it’s done you should see something like this:
Now go ahead and connect the adapter. You should get a pop-up looking like this:
Finally Windows should report that the device has been installed:
On Device Manager you should be looking at something like this:
Plugable PL2303-DB9 USB Serial Adapter Troubleshooting in Windows
Originally authored by: David Roberts, December 9, 2013
The Plugable USB serial adapter allows you to connect legacy devices that use RS232 serial communications to computers that do not have a serial port. Although this usually works well, a number of problems can crop up because many of the devices people want to connect are older devices with various issues. A frequent problem is that the software that is necessary to connect to the device does not work under modern operating systems such as Windows 7 or above. Other problems can include using an improper cable, incorrect port settings, or a basic incompatibility between the Plugable USB serial adapter and the device it is being connected to.
Drivers don’t load correctly, or the cable cannot be seen in Device Manager
When the cable is plugged into Windows 7 or higher computers, the necessary driver should load automatically. If it does not load, make sure the computer is connected to the internet. If an internet connection is not available, download the latest drivers for the cable from the Plugable driver site here. For earlier Windows XP and Vista computers, the drivers must be downloaded from the Plugable website and installed.
The drivers load successfully, but I can’t communicate with my device
Serial communications over RS232 is a legacy from an earlier age in computer when devices were not necessarily plug-and-play. Several different variables come into play, and all must be set up correctly to ensure communications.
Many legacy devices came with specialized software that is used to communicate with them over a RS232 serial port. Many of these programs were written years ago, and are not as automated as modern applications. In many cases, the software is not compatible with modern Windows operating systems. If the software won’t run, or runs with errors, check the website of the device maker to see what Windows version it is compatible with. Many times you will see a warning notice saying that the software does not work with certain versions of Windows and no update is anticipated. For example, Nikon digital cameras from the late Nineties used a serial connection to transfer photos to a computer. However, this software does not support Windows Vista or later, and Nikon warns on its website that no update is anticipated.
Some devices don’t come with special software. Instead you communicate with them using a standard serial communications program. A popular and easy to use program is Putty, which can be downloaded for free from the internet. It is also possible to send commands to the COM port directly from the Command Prompt, but this is for experts only.
In Windows, serial communications proceed through a COM port that is assigned by Windows when the USB serial adapter is plugged in. You can find out this COM port by opening Device Manager, going to Ports (COM & LTPT) and looking for Prolific USB-to_Serial Comm Port (COM#). The # symbol represents the port number of the COM port assigned by Windows. This port must be set correctly in whatever application is trying to communicate through that port.
Because older Windows computers only offered COM ports 1 through 4, many legacy applications require the COM port to be set within this range. Some applications only allow ports 1 or 2 to be set. If the port is out of the range required by the application, you can change the port number by right-clicking on the adapter in Device Manager, selecting Properties, selecting the Port Settings tab, then clicking Advanced. Clicking on the COM Port Number button reveals a list of ports, with unavailable ones listed as “in use.” Set the port you want here, then click OK to close the Properties dialog. Device Manager should update and show the number you selected. If it does not, make sure you have sufficient permissions to change the COM port settings.
There are many other settings that must be the same for the port and the device being communicated with. Typically the manual for the device being connected will outline the correct settings. Sometimes the application that is used with the device will allow you to change the settings required by the device.
Generally, however, the settings for the port are changed to match the settings required by the device. These settings are changed by right-clicking on the adapter in Device Manager, selecting Properties and selecting the Port Settings tab. The default settings are appropriate for many devices. However, in many cases the Bits per second, or “baud rate” can be set higher for faster communications. Data bits, Parity, and Stop bits change the format of the data sent to the device. Typically, if these are set wrong, the device will not be able to understand anything sent to it. Flow control selects a hardware (requires a special cable) or software method for controlling communications between the devices that keeps their communications synchronized. Most devices don’t use flow control, and for them, this can be set to Off.
Historically, COM ports were used for serial communications with modems, that took the digital information and modulated it for transmission over telephone lines or radio. Information sent from one modem went to the receiver on the other modem, and was forwarded to the receiving pin on the COM port of the destination computer. Because this “crossover” function was performed by the modems, the cable from the computer to the modem was straight cable, connecting the send pin on the source computer to the send pin on the modem.
However, when two computers were directly connected to each other, without the intervening modems that connected send to receive, a special cable, called a “null modem” or “crossover” was used that connected the send (Xmit or TX) pin on the source computer to the receive (RECV or RX) pin on the destination computer.
Which cable to use depends on how the connected device sees itself in relation to the computer. Typically devices that actually do something will require a Null Modem cable, while devices that process data and send it somewhere else (like a modem) will use a straight cable. It’s always good to get the make and model of the device being connected and go online to find out which cable is needed. Many devices come with a cable, which should be used if it is available
If the software is compatible, the port settings are made correctly, and the right cable is used, there are still some cases where the device does not work well with a particular USB Serial adapter. Some manufacturers advise against USB serial adapters alltogether or their website or recommend using a particular chipset. The major alternative available is the FTDI chipset. It is more expensive and works in some situations where the Prolific chipset used in the Plugable serial adapter will not work. Check the manufacturer’s documentation and online forums for information. You can google “<product make and model> USB serial adapter” (without the quotes). Often you’ll find a forum post by someone who has tried using a USB serial adapter and has discovered what works.
How to Connect to a Serial Device - Linux
Three ways to send and receive data from Serial devices in Linux
Identify the serial device
There are a few ways to find the serial adapter connected to the computer.
For USB serial devices like our PL2303-DB9 USB Serial Adapter, connect the adapter to the computer, then open a terminal and run:
dmesg | tail
Look for output like:
[54221.132226] usb 1-2.2: pl2303 converter now attached to ttyUSB0
This indicates the serial adpater can be accessed at /dev/ttyUSB0
Alternatively, you can run the following command to print out the newest created serial adapter:
ls -tr1 /dev/tty* | tail -n 1
This will output something similar to:
Screen is a full-screen window manager capable of connecting to serial devices.
To connect to the serial device at 9600 baud (one of the more common buad rates) run the following command in the terminal:
screen /dev/ttyUSB0 9600
From here you can type text into the terminal to transmit to the connected device, or read output from the device.
Screen commands consist of "C-a" or ctrl+a (holding down the control key, and then pressing the 'a' key, then releasing both), to enter the command input mode, then commands may be entered with another key stroke.
To disconnect from the session ( while leaving it open ): Ctrl+a, Ctrl+d, you can then use the following to reattach to the session.
To quit screen and close connection: ctrl+a, k. Then 'y' when prompted to kill the session.
Minicom is a serial communication program that has a more user-friendly interface than screen, however with more options comes more choices.
To connect to the serial device at 9600 baud with minicom, from the terminal:
minicom -b 9600 -D /dev/ttyUSB0
Minicom will provide more output when connected, in my case:
Welcome to minicom 2.7.1 OPTIONS: I18n Compiled on Jul 22 2021, 00:00:00. Port /dev/ttyUSB0, 10:42:24 Press CTRL-A Z for help on special keys
From here you can type into the terminal to send to connected serial device.
To quit, similar to Screen, the commands are accepted through key commands. Ctrl+A, z, x will disconnect and close the application.
Minicom may store presets and can be configured using the setup mode, but it is not necessary for basic useage.
We can directly write to the serial device from bash by redirecting the output of the 'echo' command to the serial device. First we need to set the serial port speed and then send the text "helloworld" to the serial device:
stty -F /dev/ttyUSB0 speed 9600 echo helloworld >/dev/ttyUSB0
This method will not print responses from the serial device, and is most useful for one-way communication with a device, for example sending a string of text to an LED matrix display.
Most permission denied error messages can be resolved by adding your user account to the 'dialout' group or the group with control of the serial port. We can check the group ownership of the port with the following:
ls -l /dev/ttyUSB0
crw-rw----. 1 root dialout 188, 0 Jan 21 11:05 /dev/ttyUSB0
In this case I would need to add my user account to the 'dialout' group:
sudo usermod -a $(whoami) -G dialout
`$(whoami)` can be replaced with your user name. Once added to the group, close and reopen the terminal, log out and back in, or restart the computer for the changes to take effect.
This is most often caused by incorrect baud rate settings on either the computer or device. Most serial devices like network routers and switches will have either a sticker with the serial port settings, or these can be found in the user manual for the device. For device with additional settings minicom may prove to be the easiest to configure.