Plugable USB to RS-232 DB9 Serial Adapter (Prolific PL2303HX Chipset) Help


I just received and installed the Plugable USB to RS-232 DB9 Serial Adapter (Prolific PL2303HX Chipset) on a MacBook Pro running 10.7. According to this installing-a-usb-serial-adapter-on-mac-os-x article/ my installation was successful.

I have a summa vinyl cutter/plotter hooked up through this adapter. The plotter software is able to communicate with the plotter and get back the material size that is loaded. However when a job is sent nothing is happening. I’ve checked and tried different baud rates, parities, handshakes etc…

The plotter manufacturer is looking into it and will be calling me back. The serial cable used is supplied from summa as it is pinned out differently according to them.

While I await for them to call me back and say that they can’t support the serial adapter would anyone like to chime in?



Hi Paul,

Thanks for posting your question here, we’ll be happy to help. It sounds like the communication is happening because the Plotter software is able to communicate with the plotter and get back the material size. Also, our USB to Serial cable translates a standard serial connection into USB so it is compatible with standard serial devices and cables. Can you describe how you are connecting to your vinyl cutter? Do you have the proprietary cable connected to the cutter?

Let me know more about the details and the make and model of your cutter and I’ll figure out next steps.

Thank you,

Plugable Technologies


The vinyl cutter is a SUMMA D120SE. Im using the proprietary cable from summa with the plugable usb to serial. The software being used is MacSign from

According to SUMMA, a lot of people use usb to serial converters with their cable without a problem on the Windows PC side. They could not figure out why it wasn’t working in my case. My next step is getting in touch with softeam to see if its a software problem.

Thanks for taking the time.



Hi Paul,

Is there any other software you can use to verify communication with the cutter? Are you able to start jobs from the cutter itself? I see on the Summa website that they have a cutter control and a separate cutter tools package. Would it be possible to verify your setup with one or both of these packages? Otherwise, I think you are correct in following up with the MacSign providers.

Do you have any other serial devices you can connect to the USB to Serial cable and verify that the cable and the installation on your Mac are in order? That way, we’ll be able to focus on the cutter software, cable and the cutter itself.

Thanks for your patience,

Plugable Technologies