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Groups > comp.lang.python > #24494 > unrolled thread
| Started by | "Adam" <adam@no_thanks.com> |
|---|---|
| First post | 2012-06-26 21:12 -0700 |
| Last post | 2012-06-27 14:53 +0000 |
| Articles | 3 on this page of 23 — 7 participants |
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PySerial could not open port COM4: [Error 5] Access is denied - please help "Adam" <adam@no_thanks.com> - 2012-06-26 21:12 -0700
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help John Nagle <nagle@animats.com> - 2012-06-26 22:33 -0700
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help "Adam" <adam@no_thanks.com> - 2012-06-27 02:10 -0700
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help Paul <nospam@needed.com> - 2012-06-27 08:28 -0400
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help "Adam" <adam@no_thanks.com> - 2012-06-27 08:26 -0700
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help Paul <nospam@needed.com> - 2012-06-27 12:04 -0400
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help "Adam" <adam@no_thanks.com> - 2012-06-27 10:41 -0700
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help Paul <nospam@needed.com> - 2012-06-27 14:04 -0400
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help "Adam" <adam@no_thanks.com> - 2012-06-27 13:40 -0700
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help Grant Edwards <invalid@invalid.invalid> - 2012-06-27 21:18 +0000
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help "Adam" <adam@no_thanks.com> - 2012-06-27 14:48 -0700
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help Grant Edwards <invalid@invalid.invalid> - 2012-06-27 22:06 +0000
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help Grant Edwards <invalid@invalid.invalid> - 2012-06-27 22:18 +0000
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help Temia Eszteri <lamialily@cleverpun.com> - 2012-06-27 15:31 -0700
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help "Adam" <adam@no_thanks.com> - 2012-06-27 15:51 -0700
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help Grant Edwards <invalid@invalid.invalid> - 2012-06-27 23:24 +0000
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help "Adam" <adam@no_thanks.com> - 2012-06-27 17:14 -0700
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help Grant Edwards <invalid@invalid.invalid> - 2012-06-28 14:15 +0000
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help "Adam" <adam@no_thanks.com> - 2012-06-28 13:31 -0700
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help Roel Schroeven <roel@roelschroeven.net> - 2012-06-28 21:08 +0200
Re: PySerial could not open port COM4: [Error 5] Access is denied- please help "Adam" <adam@no_thanks.com> - 2012-06-28 14:48 -0700
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help "David H. Lipman" <DLipman~nospam~@Verizon.Net> - 2012-06-27 08:28 -0400
Re: PySerial could not open port COM4: [Error 5] Access is denied - please help Grant Edwards <invalid@invalid.invalid> - 2012-06-27 14:53 +0000
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| From | "Adam" <adam@no_thanks.com> |
|---|---|
| Date | 2012-06-28 14:48 -0700 |
| Subject | Re: PySerial could not open port COM4: [Error 5] Access is denied- please help |
| Message-ID | <jsijer$ick$1@dont-email.me> |
| In reply to | #24632 |
"Roel Schroeven" <roel@roelschroeven.net> wrote in message
news:mailman.1618.1340910525.4697.python-list@python.org...
> Temia Eszteri schreef:
>> Actually, I believe someone in an earlier thread in the newsgroup or
>> elsewhere pointed out that serial ports automatically open under
>> Windows. I'd have to look it back up when I have the time, which I
>> don't have at the moment, unfortunately.
>
> That doesn't have anything to do with Windows, but with how pySerial
> works. See the documentation for __init__():
>
> "The port is immediately opened on object creation, when a port is given.
> It is not opened when port is None and a successive call to open() will be
> needed."
>
> So if your script does something like
>
> prt = serial.Serial('COM4')
>
> then pySerial automatically opens the port, and you shouldn't call
> prt.open() anymore.
>
> If, on the contrary, you do something like
>
> prt = serial.Serial()
> prt.port = 'COM4'
>
> then pySerial doesn't open the port, and you have to call prt.open() to do
> it.
>
> PySerial has this same behavior on both Windows and Linux. The difference
> might be that on Linux it is possible to open serial ports more than once,
> while that doesn't work on Windows.
>
> Best regards,
> Roel
>
Thanks for the info. Your explanation helps a lot.
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| From | "David H. Lipman" <DLipman~nospam~@Verizon.Net> |
|---|---|
| Date | 2012-06-27 08:28 -0400 |
| Message-ID | <M6ydnb5ji7wYYXfSnZ2dnUVZ_t-dnZ2d@giganews.com> |
| In reply to | #24498 |
From: "Adam" <adam@no_thanks.com>
>
> "John Nagle" <nagle@animats.com> wrote in message
> news:jse604$1cq$1@dont-email.me...
>> On 6/26/2012 9:12 PM, Adam wrote:
>>> Host OS: Ubuntu 10.04 LTS
>>> Guest OS: Windows XP Pro SP3
>>>
>>> I am able to open port COM4 with Terminal emulator.
>>>
>>> So, what can cause PySerial to generate the following error ...
>>>
>>> C:\Wattcher>python wattcher.py
>>> Traceback (most recent call last):
>>> File "wattcher.py", line 56, in <module>
>>> ser.open()
>>> File "C:\Python25\Lib\site-packages\serial\serialwin32.py", line 56,
>>> in
>>> open
>>> raise SerialException("could not open port %s: %s" % (self.portstr,
>>> ctypes.WinError()))
>>> serial.serialutil.SerialException: could not open port COM4: [Error 5]
>>> Access is denied.
>>
>> Are you trying to access serial ports from a virtual machine?
>> Which virtual machine environment? Xen? VMware? QEmu? VirtualBox?
>> I wouldn't expect that to work in most of those.
>>
>> What is "COM4", anyway? Few machines today actually have four
>> serial ports. Is some device emulating a serial port?
>>
>> John Nagle
>>
> Thanks, and yes, I am using VirtualBox. My laptop does not have a serial
> port so
> I use a USB-to-serial converter, which is assigned COM4.
>
Then it is a Virtual COM port. Often software will want to communicate
directly to the COM4 port which is usually at: IRQ3 and I/O 2E8h.
--
Dave
Multi-AV Scanning Tool - http://multi-av.thespykiller.co.uk
http://www.pctipp.ch/downloads/dl/35905.asp
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| From | Grant Edwards <invalid@invalid.invalid> |
|---|---|
| Date | 2012-06-27 14:53 +0000 |
| Message-ID | <jsf6ph$sf9$1@reader1.panix.com> |
| In reply to | #24507 |
On 2012-06-27, David H. Lipman <DLipman~nospam~@Verizon.Net> wrote:
> From: "Adam" <adam@no_thanks.com>
>> "John Nagle" <nagle@animats.com> wrote in message
>> news:jse604$1cq$1@dont-email.me...
>>> On 6/26/2012 9:12 PM, Adam wrote:
>>>> Host OS: Ubuntu 10.04 LTS
>>>> Guest OS: Windows XP Pro SP3
>>>>
>>>> I am able to open port COM4 with Terminal emulator.
>>>>
>>>> So, what can cause PySerial to generate the following error ...
>>>>
>>>> C:\Wattcher>python wattcher.py
>>>> Traceback (most recent call last):
>>>> File "wattcher.py", line 56, in <module>
>>>> ser.open()
>>>> File "C:\Python25\Lib\site-packages\serial\serialwin32.py", line 56, in open
>>>> raise SerialException("could not open port %s: %s" % (self.portstr,
>>>> ctypes.WinError()))
>>>> serial.serialutil.SerialException: could not open port COM4: [Error 5]
>>>> Access is denied.
>>>
>>> Are you trying to access serial ports from a virtual machine? Which
>>> virtual machine environment? Xen? VMware? QEmu? VirtualBox? I
>>> wouldn't expect that to work in most of those.
Except he says it _does_ work with his terminal emulator.
>>> What is "COM4", anyway? Few machines today actually have four
>>> serial ports. Is some device emulating a serial port?
It shouldn't matter. If other apps can open COM4, then pyserial
should be able to open COM4.
>> Thanks, and yes, I am using VirtualBox. My laptop does not have a
>> serial port so I use a USB-to-serial converter, which is assigned
>> COM4.
>
> Then it is a Virtual COM port. Often software will want to
> communicate directly to the COM4 port which is usually at: IRQ3 and
> I/O 2E8h.
Pyserial doesn't do that. It uses the standard win32 serial API, and
it should work just fine with any Win32 serial device (what you call a
"virtual" COM port).
--
Grant Edwards grant.b.edwards Yow! World War III?
at No thanks!
gmail.com
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