Society of Robots - Robot Forum

General Misc => Misc => Topic started by: Admin on January 31, 2009, 08:28:56 PM

Title: how to unlock frozen COM port?
Post by: Admin on January 31, 2009, 08:28:56 PM

Some program was using the COM port, reserved it, then when the program shut down (or crashed) it didn't unreserve it - but the computer still thinks the COM port is being used and won't let me use it for something else.

I could just restart my laptop, but there has to be a better way to fix this . . .

I see this problem occasionally on the SoR forum, so figured this would help many of us!

Title: Re: how to unlock frozen COM port?
Post by: pomprocker on January 31, 2009, 10:07:02 PM

Have you tried to disable/reenable it in Device manager?

Title: Re: how to unlock frozen COM port?
Post by: Admin on January 31, 2009, 10:30:25 PM

That was the first thing I checked actually. But Device manager says nothing is plugged in to USB despite the fact I hear a 'beep' noise when I plug the device into USB.

'Scan for hardware changes' has no affect.

Title: Re: how to unlock frozen COM port?
Post by: pomprocker on January 31, 2009, 11:43:26 PM

Is this com port 1-4 or or a virtual com port

Title: Re: how to unlock frozen COM port?
Post by: Admin on January 31, 2009, 11:51:06 PM

com port 1-4

Title: Re: how to unlock frozen COM port?
Post by: cosminprund on February 02, 2009, 07:12:25 AM

Did you look into Task Manager? Is the process that's locking up the COM port really gone? If it is not gone, end-process it.
Normally this should never happen, it would be a major bug in Windows (we're talking Windows, right?) - while Windows has bugs, I don't expect "major" bugs. During my play with serial ports I obviously locked my application many times, never had a problem with the port getting stuck!

Title: Re: how to unlock frozen COM port?
Post by: Admin on February 02, 2009, 08:11:41 AM

Quote from: cosminprund on February 02, 2009, 07:12:25 AM

Did you look into Task Manager? Is the process that's locking up the COM port really gone? If it is not gone, end-process it.
Normally this should never happen, it would be a major bug in Windows (we're talking Windows, right?) - while Windows has bugs, I don't expect "major" bugs. During my play with serial ports I obviously locked my application many times, never had a problem with the port getting stuck!

Yeap, I killed the process, but still wouldn't work. I see this bug probably 2 or 3 times a year on my PC, and occasionally on other peoples PC's.

Title: Re: how to unlock frozen COM port?
Post by: Joesavage1 on February 02, 2009, 09:28:29 AM

do ANY of the COM ports work?

Title: Re: how to unlock frozen COM port?
Post by: Admin on February 02, 2009, 09:34:35 AM

Well I already restarted my PC yesterday so its all working fine now.

I didn't try to test all of my ports, I just know I was on port 2 and it refused to connect to that port with my Axon plugged in.

Title: Re: how to unlock frozen COM port?
Post by: Joesavage1 on February 02, 2009, 09:41:24 AM

Ok, must be a Win XP problem although ive never had the problem myself.

Joe (BTW nice meeting you Admin, never spoke to you before =D)

Title: Re: how to unlock frozen COM port?
Post by: Admin on February 02, 2009, 10:06:30 AM

sup. :P

(it could also be a driver problem)