Installing a USB Serial Adapter on Mac OS X

The easiest way to go about installing our Plugable USB to Serial adapter is by starting with the device.

  • If you want to verify that the adapter and the driver were installed properly click here

Connect the device to the Mac. Once connected click on the Apple icon and on ‘About This Mac’

Click on ‘More Info…’

Click on ‘USB’ on the left and on the ‘USB-Serial Controller D’
If all is well you should be seeing something like this:

Time to get the driver! Fire up Safari and browse to and scroll down to Mac.
Click on the ‘PL2303 MacOSX10.6 dmg’, the Safari Downloads window should come up:

Double click on the md_PL23-3_MacOSX10

Now double click on the PL2303_1.4.0.dmg to mount the image

Now double click on the PL2303_1.4.0 to start the installation

Once the installer comes up click ‘Continue’ to proceed.

Then ‘Select a Destination’ click on your desired drive and click ‘Continue’ to move forward

Now just click ‘Install’ to continue.

You may be asked of your username and password – enter them and click ‘OK’

You’ll get a warning about restarting the computer after the installation is complete. This is normal, click ‘Continue Installation‘.

Installing should start (takes a couple of minutes to complete)

When it’s done you should see this:

Click on ‘Restart’ to reboot the Mac.

 After you restart, check that everything has installed OK.
On the Mac there are two methods to determine this:

Method 1:
Click on ‘Applications’

Click on ‘Utilities’

Click on ‘Terminal’

kextstat | grep prolific
ioreg -c IOSerialBSDClient | grep usb
Your results should be very close to this:

Method 2:
Click on ‘System Preferences’

Click on ‘Network’

Now click on the ‘+’ sign on the bottom left, and then on the ‘Select the interface and enter a name for the new Service’ click on ‘Interface’ – you should be seeing the ‘USB-Serial Controller D’ there.

This will create a “Network” interface for a modem or serial port. Because it’s a serial port, it’ll say “Not Configured” and that’s normal:

From the “Advanced” button you can change default settings (usually not needed). And this won’t change the “Not Configured” message – that’s still ok.

Now finally, you need an application which will talk to the serial port. On Mac, the file which maps to the port is /dev/cu.usbserial. If you have a null modem cable and a terminal program on the other side, the Mac actually has a built-in terminal program called “screen” that you can use to test the connection.

Once that is up and connected (and if the serial ports are set to the same baud rate and paramters), you can type on either side and see the characters come across.


USB Serial on the Mac is a real melding of the very new and very old. If you have any trouble, just visit to see existing FAQs for Plugable’s USB Serial adapter.

Where to Buy

[amtap amazon:asin=B00425S1H8]

105 comments on “Installing a USB Serial Adapter on Mac OS X”

  1. David Roberts David Roberts Reply


    Thank you for your comment. We are going to try to reproduce this problem, and if we can, we’ll post our findings here. Also, we would be grateful if anyone experiencing this issue could open a support ticket by sending an email about the problem to Thanks!

  2. Nelson Anacleto Reply

    I have the same problem with me Enttec DMX Pro: My message error is :
    /dev/tty.usbserial-00002014: Permission denied

    Any help ???

    • David Roberts David Roberts Reply

      Hi Nelson,

      Permission denied errors usually mean you don’t have sufficient permissions to access a device directly. Try accessing /dev/tty.usbserial-00002014 as root through su or sudo.

      Plugable Support

  3. sauly87 Reply

    also i have found that attempting to find the right bit rate the screen daemon gets stuck running and will error next time connecting with cannot find PTY – open activity monitor and show all process and find screen and force quit to resolve

  4. jj Reply

    Had to boot up an old V240, found my trusty old usbserial cable, only had iMac so googled driver, found this page, have to compliment author on a simple ABC process that works a treat :)

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  7. Chris K Reply

    There’s a new terminal app called Serial available on the Mac App Store that works with the Plugable USB-serial adapter without requiring any drivers. I wrote it to make serial ports easier to work with on the Mac. You’ll still want the driver if you want other apps to be able to use the port, but if you just need a terminal, this may save you some time.

    • gene counts Reply

      Chris: Have read and re-read your post seven times. Would you be able to list a few steps? I have old Dell running Windows 7. Need to transfer everything from this to new IMac. Already transferred Sony laptop over with HDMI cable.
      I don’t understand “terminal app”, “pluggable USB-serial adapter”, etc.
      If you would list, say, five-seven easy steps including what “buttons” to push(for dummies) would be in your debt.

      Would appreciate any and all comments from the community.

  8. Patric Neumann Reply

    Hello Chris,

    Thank you for taking the time for sharing this with us.This is a great official alternative solution that we can offer from now on.

    Kind regards,
    Plugable Technologies

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  10. Ivan Barkovic Reply

    Thank you for posting. I have the same USB adapter and this tutorial works with macbook pro 13″ 2013, OSX 10.9.4

  11. Abner Ortiz Reply

    it does not work with my Yosemite. I have the Belkin F5U257, and f5u409 belkin. It does not work. please help. I have installed everything that this user said, but it still no work. please help

    • Bernie Thompson Bernie Thompson Reply

      Hi Abner – Thanks for posting. We’re only able to help with our own (Plugable) products. The chipset, driver, or other details could be different with the Belkin. You’ll want to contact them for support. Thanks!

  12. Jaessr Reply

    I searched for hours to find a solution but couldn’t find anything. Is there a way to show which Com Port of the adapter is used??? I have a windows application running with wine were the app asked me for the com port and it’s very annoying to check every port which is listed just to see if i’ve chosen the correct one.

      • Merlin Marschall Reply

        I am using a mac. Wine is a Windows port making it possible to run Windows applications on Mac or Linux. It can use the Mac Hardware such as the adapter and forward it to the Windows application. Nonetheless i found my answer already but thanks anyway

      • Jaessr Reply

        Wine is a Crossover App to run Windows apps on Mac using the Macs hardware. So i didn’t look for informations regarding Windows ;). Anyway i found the solution and anybody who’s interested check the answer i gave Frode Vatne down below ;)
        Thanks anyway

      • Jaessr Reply

        Yes i did. In Terminal you have to go to your Wine WrapperApp dosdevices folder. In my case “cd library/Application\ Support/AudioCore_14162611962482/dosdevices” and then simply enter “ln -s /dev/cu.usbserial com1″
        The AudioCore folder here is your application name so you have to enter a your wrapper name.
        Now com1 will be used with the adapter

        • Jaessr Reply

          but make sure u follow this sites instruction on how to install the driver first!!!! otherwise it won’t work at all

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