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Post 10.10 USB-Serial Converter needs reboot to work

Guys,


I have a PL2303 based USB-Serial converter that I use every day for my work (to connect via serial port to network devices)


Up until now it was working perfectly fine. After upgrading to 10.10, it simply will not work until I reboot my mac book air. It goes like this...


Plug in USB serial converter, connect to network device.


Start up iterm or terminal, check the device exists:


Carls-MacBook-Air:~ carlnewton$ ls /dev | grep 230

cu.PL2303-00001014

tty.PL2303-00001014


"screen" to the device using 9600 BAUD, as per the profile configured in my Iterm client:


screen /dev/tty.PL2303-00001014 9600


The screen is successful, but I get no output at all, just a flashing cursor.


I then unplug the serial, reboot my mac, plug it back in and it works fine. It will continue to work fine until my mac goes to sleep from inactivity, I put it to sleep or shut it down.


I then will have to reboot it again to get it to work.


Any ideas anyone? Im not sure how to troubleshoot this, the device exists, and looks no different in /dev when its working or when its not working, I have a cu. Device and a tty. device both times.


Thanks in advance!

MacBook Air, OS X Yosemite (10.10)

Posted on Nov 7, 2014 4:51 AM

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Posted on Dec 6, 2014 12:25 PM

I managed to resolve this.


I downloaded a different driver for the PL2303 based chipset. I can't remember now exactly where I got it from; But it works slightly differently.


The old one used to list the device as something like "tty.PL2303USB0004" or something. This driver DID NOT work with 10.10


The new one now lists the devices as something like "tty.usbserial" and this one works just fine with 10.10 Yosemite

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Question marked as Best reply

Dec 6, 2014 12:25 PM in response to Delarado

I managed to resolve this.


I downloaded a different driver for the PL2303 based chipset. I can't remember now exactly where I got it from; But it works slightly differently.


The old one used to list the device as something like "tty.PL2303USB0004" or something. This driver DID NOT work with 10.10


The new one now lists the devices as something like "tty.usbserial" and this one works just fine with 10.10 Yosemite

Apr 15, 2015 10:36 AM in response to Delarado

I had the same symptom.. I loaded the latest prolific drivers that support yosemite 10.10.. but I get no connectivity when I issue a screen /dev/tty.PL2303-00002014 command. However, I did an ls /dev/tty.u* and see there is also a tty.usbserial driver. When I issue the screen command "screen /dev/tty.usbserial 9600" it works. 🙂 I followed the prolifics install guide to delete previous drivers before I loaded their latest driver.. so I don't "think" the tty.usbserial came with some other driver.


FYI - The prolific help guide also recommended roger meier's freeware coolterm app. I looked it up and tried it ... very nice graphical interface for simple terminal utility.

May 30, 2015 3:19 AM in response to musiccitymcbride

Yes, they may indeed compete with each other. Open your boot disk, going into /System/Library/Extensions, where you'll find files containing "2303" or "Prolific" in their name. Remove either to disable them, then reboot.


The one named Prolific is the one coming from the manufacturer in Taiwan, using "usbserial" as the serial port name. However, I found that it did not work with 10.10.3 (tried on two Macs) with 9600 8N1 settings, receiving only garbage, whereas a different popular driver (e.g. from http://www.xbsd.nl/2011/07/pl2303-serial-usb-on-osx-lion.html) works without producing garbage but doesn't control CTS/DTR correctly for me.

Post 10.10 USB-Serial Converter needs reboot to work

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