USB-Serial hangs, El Capitan

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Jef D Author

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USB-Serial hangs, El Capitan

TRIPPLITE-Keyspan USA-19UHS with OSX10.11 Driver

OSX is 10.11.1

- Using this USB-RS232 in a MacPro 3.1, Early 2008.

- The adapter is recognized and all the serial programs can recognize the /dev/ kext

- Functions like RTS and DTR are working OK.

- When sending OUT data/text the data is output by the Tripplite adapter

- As soon as receiving any data/text by the Tripplite (towards the Mac), the serial program ‘hangs’.

- After a force-quit of the serial program, it can not be restarted again.

- Checked with several serial programs including terminal-screen.

- Checked also with another serial communication device, using FTDI kext driver: same problem.

- When putting the MacPro in Windows mode via Bootcamp, the Keyspan adapter works OK! So hardware is good.

These adapters are functioning OK on my Macbook-Pro 8.2 with El Capitan!

I tried for 2 day's lots of things, clearing cashes, resetting SMC and PRAM, latest kext drivers etc, no result.

I'm not sure where to start now, and a clean install of the OSX is not really an option now...

Thanks for helping me out!

Mac Pro, OS X El Capitan (10.11.1)

Posted on Oct 24, 2015 8:24 AM

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Answer 1

Jef D Author

Level 1

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Oct 25, 2015 10:03 AM in response to Jef D

What I discovered today:

I'm using a Cinema HD display and it has a fire-wire and USB cable to connect to the MacPro. When connecting, this becomes a USB 2.0 hub. The other ports are indicated as USB hub.

When connecting the Keyspan adapter to the USB 2.0 hub (located on the monitor) the adapter works OK!

It's not clear to me why the USB ports are not installed as USB 2.0 ports.

When I insert a USB-memory stick at any of the ports, it is listed under USB 2.0 Bus...

I would appreciate your comment, thanks

When attaching the Keyspan (Not working good) to a free USB Bus:

USB 2.0 Bus

-Hub

-Keyboard Hub

Apple Optical USB Mouse

Apple Keyboard

-Apple Cinema HD Display

USB Bus

-Keyspan USA-19H

USB Bus

Bluetooth HCI

When attaching the Keyspan (Working Good) to Cinema HD USB hub:

USB 2.0 Bus

-Hub

-Keyspan USA-19H

-Keyboard Hub

Apple Optical USB Mouse

Apple Keyboard

-Apple Cinema HD Display

USB Bus

Bluetooth HCI

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Answer 2

Mar 8, 2016 6:30 AM in response to Jef D

Hi Jef,

Thanks for your post. Do you have any more news, by any chance?

I have exactly the same symptoms, with hardware from roughly the same era (MacBookPro, Late 2007), running OS X 10.11.3, 32-bit.

The only clarifications I have:

- CPU time for kernel_task goes through the roof, indicating a driver problem.

- My Bluetooth mouse quits working, indicating a really nasty driver problem.

After reading your post, I tried inserting a USB hub – bingo presto, it works!

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Answer 3

Mar 8, 2016 6:52 AM in response to Jef D

P.S. I sent a bug report to intlservice@tripplite.com, FWIW.

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