Can't Connect my Serial Device Through USB to Serial Adapter on Mac OS X 10.10.4

I have recently moved from Windows to Mac (OS X 10.10.4) and am trying to get my Prolific PL2303 USB-to-serial adapter working (v_1_5_1 driver). I’ve followed the installation PDF successfully to the point where tty.usbserial is listed as expected in Terminal. My application (Golden Cheetah) cannot see my device (SRM cycle power control PCV), reporting that it’s unable to open the device on any baud rate at /dev/cu.usbserial. I appreciate that the application cannot be supported here, but are there any diagnostics beyond those below that I can perform to test the device and isolate where the issue is? (I am a Mac/Unix numpty so any instructions need to be pretty explicit please!)

Hardware is all proven and working fine on Windows 7.

System Profiler:
USB-Serial Controller D:

Product ID: 0x2303

Vendor ID: 0x067b (Prolific Technology, Inc.)

Version: 4.00

Speed: Up to 12 Mb/sec

Manufacturer: Prolific Technology Inc.

Location ID: 0x14100000 / 13

Current Available (mA): 500

Current Required (mA): 100

kextstat | grep prolific
128 0 0xffffff7f8383b000 0x7000 0x7000 com.prolific.driver.PL2303 (1.5.1)

ioreg -c IOSerialBSDClient | grep usb

| | | | | “IOTTYBaseName” = “usbserial”
| | | | | “IOCalloutDevice” = “/dev/cu.usbserial”
| | | | | “IODialinDevice” = “/dev/tty.usbserial”
| | | | | “IOTTYDevice” = “usbserial"

ls /dev/*usbserial*
/dev/cu.usbserial /dev/tty.usbserial

Hi Des,
Thank you for posting your question.

Everything looks good, so I don’t think it is a hardware issue (as you noted) or an installation issue.

I did some checking around about the SRM PowerControl, but I’m not finding information about its serial interface. However, you might want to check if the device needs a null modem cable (one that connects sent to receive and vice-versa). Many periphiral devices do.

If you could tell me which version of the SRM PowerControl you have, that may help me find a manual with the appropriate infromation. Otherwise, you may wish to contact the company that makes it.

Thank you,

Plugable Support

Thanks for rapid response David.

I resolved my issue via this Wiki link:…