PySerial could not open port COM4: [Error 5] Access is denied - please help
Adam
adam at no_thanks.com
Wed Jun 27 16:40:19 EDT 2012
"Paul" <nospam at needed.com> wrote in message
news:jsfhv2$ta9$1 at dont-email.me...
> Adam wrote:
>
>>
>> This is a tough one.
>
> Try
>
> handle -a > allhand.txt
>
> Then open the allhand.txt with Notepad and look for interesting entries.
>
> *******
>
> I tested right now, and first opened a session in HyperTerminal with one
> of my USB to serial adapters. The second serial adapter, is connect to a
> UPS, looking for a shutdown message. So the second entry should be present
> at all times.
>
> hypertrm.exe pid: 3452
> ...
> 120: File (---) \Device\VCP1
>
>
> ups.exe pid: 1568 NT AUTHORITY\SYSTEM
> ...
> 98: File (---) \Device\VCP0
>
> I don't have any "serial" entries on this machine. But one of
> my other machines, has a real COM port on the SuperI/O chip,
> so the entries for that would involve the word "serial" in some
> way. The USB ones, at least the ones I've got, say VCP. Possibly
> because one of the driver files sets up virtual COM ports. There
> is a control panel for the driver, that maps a virtual COM port,
> to a COM port number, like COM3 and COM4 in this case.
>
> Paul
Thanks (Guru Paul), you're the best. I think we may have something this
time ...
144: File (---) \Device\ProlificSerial3
And, TeraTerm (using COM4) is open and receiving data wirelessly.
>From the output generated by "handle -a", here's the section for TeraTerm
...
------------------------------------------------------------------------------
ttermpro.exe pid: 3648 VBOX_WINXPPRO\adam (claims to use COM4)
4: KeyedEvent \KernelObjects\CritSecOutOfMemoryEvent
8: Directory \KnownDlls
C: File (RW-) D:\downloads\Tera Term Pro\ttpro313
10: Event
14: Directory \Windows
18: Port
1C: WindowStation \Windows\WindowStations\WinSta0
20: Desktop \Default
24: WindowStation \Windows\WindowStations\WinSta0
28: Directory \BaseNamedObjects
2C: Section \BaseNamedObjects\ttset_memfilemap
30: Semaphore
34: Semaphore
38: Key HKLM
3C: Event
40: Semaphore
\BaseNamedObjects\shell.{A48F1A32-A340-11D1-BC6B-00A0C90312E1}
44: File (RW-)
C:\WINDOWS.0\WinSxS\x86_Microsoft.Windows.Common-Controls_6595b64144ccf1df_6.0.2600.6028_x-ww_61e65202
48: File (---) \Device\KsecDD
4C: Key HKCU
50: Key HKCU\CLSID
54: File (RW-)
C:\WINDOWS.0\WinSxS\x86_Microsoft.VC80.CRT_1fc8b3b9a1e18e3b_8.0.50727.6195_x-ww_44262b86
58: Mutant
5C: Event \BaseNamedObjects\crypt32LogoffEvent
60: Event
64: Mutant
68: Event
6C: Event
70: Section
\BaseNamedObjects\_ISWINTERNAL_EPT32_SHEX_K32_0_1c9aa25ea688500_7c80_S-1-5-21-1801674531-1078145449-1957994488-1004
74: Event
78: File (RWD) C:\DOCUME~1\adam\LOCALS~1\Temp\IswTmp\Logs\ISWSHEX.swl
7C: Semaphore
80: Semaphore
84: Semaphore
88: Semaphore
8C: Semaphore
90: Semaphore
94: Semaphore
98: Semaphore
9C: Semaphore
A0: Semaphore
A4: Semaphore
A8: Semaphore
AC: Section
\BaseNamedObjects\_ISWINTERNAL_EPT32_SHEX_A32_0_1c98aa70f70ec00_77dd_S-1-5-21-1801674531-1078145449-1957994488-1004
B0: Port
B4: Section
B8: Key HKCU
BC: Mutant
\BaseNamedObjects\CTF.LBES.MutexDefaultS-1-5-21-1801674531-1078145449-1957994488-1004
C0: File (---) \Device\Tcp
C4: File (---) \Device\Tcp
C8: File (---) \Device\Ip
CC: File (---) \Device\Ip
D0: File (---) \Device\Ip
D4: Semaphore
D8: Semaphore
DC: Key HKLM\SYSTEM\ControlSet001\Services\Tcpip\Linkage
E0: Key HKLM\SYSTEM\ControlSet001\Services\Tcpip\Parameters
E4: Key
HKLM\SYSTEM\ControlSet001\Services\NetBT\Parameters\Interfaces
E8: Key HKLM\SYSTEM\ControlSet001\Services\NetBT\Parameters
EC: Thread ttermpro.exe(3648): 3684
F0: Event
F4: Key
HKLM\SYSTEM\ControlSet001\Services\WinSock2\Parameters\Protocol_Catalog9
F8: Event
FC: Key
HKLM\SYSTEM\ControlSet001\Services\WinSock2\Parameters\NameSpace_Catalog5
100: Section
\BaseNamedObjects\CiceroSharedMemDefaultS-1-5-21-1801674531-1078145449-1957994488-1004
104: Key HKLM\SOFTWARE\Microsoft\SystemCertificates\My
108: File (RW-) D:\downloads\Tera Term Pro\ttpro313\httplog.log
10C: Mutant
\BaseNamedObjects\CTF.Compart.MutexDefaultS-1-5-21-1801674531-1078145449-1957994488-1004
110: Mutant
\BaseNamedObjects\CTF.Asm.MutexDefaultS-1-5-21-1801674531-1078145449-1957994488-1004
114: Mutant
\BaseNamedObjects\CTF.Layouts.MutexDefaultS-1-5-21-1801674531-1078145449-1957994488-1004
118: Mutant
\BaseNamedObjects\CTF.TMD.MutexDefaultS-1-5-21-1801674531-1078145449-1957994488-1004
11C: Mutant
\BaseNamedObjects\CTF.TimListCache.FMPDefaultS-1-5-21-1801674531-1078145449-1957994488-1004MUTEX.DefaultS-1-5-21-1801674531-1078145449-1957994488-1004
120: Section
\BaseNamedObjects\CTF.TimListCache.FMPDefaultS-1-5-21-1801674531-1078145449-1957994488-1004SFM.DefaultS-1-5-21-1801674531-1078145449-1957994488-1004
124: Mutant \BaseNamedObjects\ShimCacheMutex
128: Section \BaseNamedObjects\ShimSharedMemory
12C: Mutant \BaseNamedObjects\MSCTF.Shared.MUTEX.IN
130: Event \BaseNamedObjects\ReadEnd4
134: Event
138: Section \BaseNamedObjects\MSCTF.Shared.SFM.IN
13C: Event \BaseNamedObjects\Write4
140: Event \BaseNamedObjects\ReadEnd4
144: File (---) \Device\ProlificSerial3
148: Event \BaseNamedObjects\Read4
14C: Thread ttermpro.exe(3648): 272
150: Section \BaseNamedObjects\MSCTF.Shared.SFM.EGO
154: Event
158: Mutant \BaseNamedObjects\MSCTF.Shared.MUTEX.EGO
------------------------------------------------------------------------------
The Python script needed a call to ser.close() before ser.open() in order to
work.
Yes, that's right ... things are working fine now. :-)
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