我正在使用Python3.5.1 serial module。当我打开一个端口时，它失败，出现操作系统错误22（Windows错误87），表示failure to configure port, one of the arguments in OPEN system call were incorrect, or malformed.
我的代码使用循环通过串行设置 - 将错误的数据包发送到设备，直到设备响应（可读）错误消息（所以我知道我的串行端口配置正确）。是的，我应该只知道设备的设置，但这不是一个完美的世界。
import serial
import time
baud_rate = [50,75,110,134,150,200,300600,1200,1800,2400,4800,9600,19200,38400,57600,115200]
parity = [serial.PARITY_ODD,serial.PARITY_EVEN,serial.PARITY_NONE]
stop_bits = [serial.STOPBITS_TWO, serial.STOPBITS_ONE]
bytesize = [serial.SEVENBITS,serial.EIGHTBITS]
timeout = 5000
for b in baud_rate:
for p in parity:
for s in stop_bits:
for bs in bytesize:
ser = serial.Serial(port='COM3',baudrate=b,parity=p,stopbits=s,bytesize=bs)
try:
if ser.isOpen():
ser.write(b'TEST')
ser.reset_output_buffer()
time.sleep(1)
out = ser.read(3)
if out[0] == 64 and out[1] == 67 and out[2] == 32:
print("dumping settings")
print(ser.get_settings())
else:
ser.close()
except SerialException:
print("Serial Exception occured.")
pass
问题发生在Windows 7 x64 Service Pack 1下.python版本是3.5。 cmd.exe实例以管理员身份运行。
我非常确定运行脚本时存在COM3
import serial.tools.list_ports
ports = list(serial.tools.list_ports.comports())
for p in ports:
print(p)
我收到了输出：
>python list_serial.py
COM3 - Prolific USB-to-Serial Comm Port (COM3)
所以我相信端口URL / URI（idfk）是正确的。
完整错误文字：
Traceback (most recent call last):
File "serial_reader.py", line 13, in <module>
ser = serial.Serial(port='COM3',baudrate=b,parity=p,stopbits=s,bytesize=bs)
File "C:\Users\FA1\AppData\Local\Programs\Python\Python35-32\lib\site-packages\serial\serialwin32.py", line 31, in __init__
SerialBase.__init__(self, *args, **kwargs)
File "C:\Users\FA1\AppData\Local\Programs\Python\Python35-32\lib\site-packages\serial\serialutil.py", line 180, in __init__
self.open()
File "C:\Users\FA1\AppData\Local\Programs\Python\Python35-32\lib\site-packages\serial\serialwin32.py", line 78, in open
self._reconfigure_port()
File "C:\Users\FA1\AppData\Local\Programs\Python\Python35-32\lib\site-packages\serial\serialwin32.py", line 220, in _reconfigure_port
raise SerialException("Cannot configure port, something went wrong. Original message: %r" % ctypes.WinError())
serial.serialutil.SerialException: Cannot configure port, something went wrong. Original message: OSError(22, 'The parameter is incorrect.', None, 87)
我确保驱动程序已正确安装，但我收到了2个不同串行转换器的错误。所以我认为这个问题与硬件或驱动程序无关。
答案 0 :(得分：2)
你说你应该只知道设备的设置，但这不是一个完美的世界＆＃34;。但Windows确实允许通过GetCommProperties查询通信设备属性。 pySerial似乎不支持此功能，但您可以使用ctypes直接调用此函数。
以下定义了一个void handler_sigcont(int sig){
printf("SIGCONT server\n");
}
int main(){
signal(SIGCONT,handler_sigcont);
printf("%d\n",getpid());
raise(SIGCONT);
printf("server!\n");
}
函数来查询comm端口的可设置属性。它接受现有设备句柄（例如pySerial端口的get_comm_properties属性）或DOS设备名称（如_handle）或WinAPI设备名称（例如COM1）。
\\.\COM1示例：
import collections
import ctypes
from ctypes import wintypes
kernel32 = ctypes.WinDLL('kernel32', use_last_error=True)
GENERIC_READ = 0x80000000
GENERIC_WRITE = 0x40000000
OPEN_EXISTING = 3
INVALID_HANDLE_VALUE = wintypes.HANDLE(-1).value
ERROR_FILE_NOT_FOUND = 0x0002
class COMMPROP(ctypes.Structure):
_fields_= (('wPacketLength', wintypes.WORD),
('wPacketVersion', wintypes.WORD),
('dwServiceMask', wintypes.DWORD),
('dwReserved1', wintypes.DWORD),
('dwMaxTxQueue', wintypes.DWORD),
('dwMaxRxQueue', wintypes.DWORD),
('dwMaxBaud', wintypes.DWORD),
('dwProvSubType', wintypes.DWORD),
('dwProvCapabilities', wintypes.DWORD),
('dwSettableParams', wintypes.DWORD),
('dwSettableBaud', wintypes.DWORD),
('wSettableData', wintypes.WORD),
('wSettableStopParity', wintypes.WORD),
('dwCurrentTxQueue', wintypes.DWORD),
('dwCurrentRxQueue', wintypes.DWORD),
('dwProvSpec1', wintypes.DWORD),
('dwProvSpec2', wintypes.DWORD),
('wcProvChar', wintypes.WCHAR * 1))
class _CONST:
COMMPROP_INITIALIZED = 0xE73CF52E
SP_SERIALCOMM = 0x00000001
BAUD_USER = 0x10000000 # programmable baud rate
DATABITS_16X = 0x0020 # hardware wide data path
PROV_SUBTYPE = collections.OrderedDict([
('UNSPECIFIED', 0x00000000),
('RS232', 0x00000001),
('PARALLELPORT', 0x00000002),
('RS422', 0x00000003),
('RS423', 0x00000004),
('RS449', 0x00000005),
('MODEM', 0x00000006),
('FAX', 0x00000021),
('SCANNER', 0x00000022),
('NETWORK_BRIDGE', 0x00000100),
('LAT', 0x00000101),
('TCPIP_TELNET', 0x00000102),
('X25', 0x00000103),
])
PROV_CAPABILITIES = collections.OrderedDict([
('DTRDSR', 0x0001), # data-terminal-ready / data-set-ready
('RTSCTS', 0x0002), # request-to-send / clear-to-send
('RLSD', 0x0004), # receive-line-signal-detect
('PARITY_CHECK', 0x0008),
('XONXOFF', 0x0010), # XON/XOFF flow control
('SETXCHAR', 0x0020), # settable XON/XOFF
('TOTALTIMEOUTS', 0x0040), # total (elapsed) time-outs
('INTTIMEOUTS', 0x0080), # interval time-outs
('SPECIALCHARS', 0x0100),
('16BITMODE', 0x0200),
])
SETTABLE_PARAMS = collections.OrderedDict([
('PARITY', 0x0001),
('BAUD', 0x0002),
('DATABITS', 0x0004),
('STOPBITS', 0x0008),
('HANDSHAKING', 0x0010), # flow control
('PARITY_CHECK', 0x0020),
('RLSD', 0x0040), # receive-line-signal-detect
])
SETTABLE_BAUD = collections.OrderedDict([
(75, 0x00000001),
(110, 0x00000002),
(134.5, 0x00000004),
(150, 0x00000008),
(300, 0x00000010),
(600, 0x00000020),
(1200, 0x00000040),
(1800, 0x00000080),
(2400, 0x00000100),
(4800, 0x00000200),
(7200, 0x00000400),
(9600, 0x00000800),
(14400, 0x00001000),
(19200, 0x00002000),
(38400, 0x00004000),
(56000, 0x00008000),
(57600, 0x00040000),
(115200, 0x00020000),
(128000, 0x00010000),
])
SETTABLE_DATA = collections.OrderedDict([
(5, 0x0001), # 5 data bits
(6, 0x0002), # 6 data bits
(7, 0x0004), # 7 data bits
(8, 0x0008), # 8 data bits
(16, 0x0010), # 16 data bits
])
SETTABLE_STOP = collections.OrderedDict([
(1, 0x0001), # 1 stop bit
(1.5, 0x0002), # 1.5 stop bits
(2, 0x0004), # 2 stop bits
])
SETTABLE_PARITY = collections.OrderedDict([
('NONE', 0x0100), # no parity
('ODD', 0x0200), # odd parity
('EVEN', 0x0400), # even parity
('MARK', 0x0800), # mark parity
('SPACE', 0x1000), # space parity
])
@property
def max_baud(self):
s = self.dwMaxBaud
m = self._CONST.SETTABLE_BAUD
if s == self._CONST.BAUD_USER:
return 0
else:
return m[s]
@property
def prov_subtype(self):
s = self.dwProvSubType
m = self._CONST.PROV_SUBTYPE
return [x for x, c in m.items() if c & s]
@property
def prov_capabilities(self):
s = self.dwProvCapabilities
m = self._CONST.PROV_CAPABILITIES
return [x for x, c in m.items() if c & s]
@property
def settable_params(self):
s = self.dwSettableParams
m = self._CONST.SETTABLE_PARAMS
return [x for x, c in m.items() if c & s]
@property
def settable_baud(self):
s = self.dwSettableBaud
m = self._CONST.SETTABLE_BAUD
return [x for x, c in m.items() if c & s]
@property
def user_settable_baud(self):
return bool(self.dwSettableBaud & self._CONST.BAUD_USER)
@property
def settable_data(self):
s = self.wSettableData
m = self._CONST.SETTABLE_DATA
return [x for x, c in m.items() if c & s]
@property
def wide_settable_data(self):
return bool(self.wSettableData & self._CONST.DATABITS_16X)
@property
def settable_stop(self):
s = self.wSettableStopParity
m = self._CONST.SETTABLE_STOP
return [x for x, c in m.items() if c & s]
@property
def settable_parity(self):
s = self.wSettableStopParity
m = self._CONST.SETTABLE_PARITY
return [x for x, c in m.items() if c & s]
LPCOMMPROP = ctypes.POINTER(COMMPROP)
class SECURITY_ATTRIBUTES(ctypes.Structure):
_fields_ = (('nLength', wintypes.DWORD),
('lpSecurityDescriptor', wintypes.LPVOID),
('bInheritHandle', wintypes.BOOL))
LPSECURITY_ATTRIBUTES = ctypes.POINTER(SECURITY_ATTRIBUTES)
kernel32.CreateFileW.restype = wintypes.HANDLE
kernel32.CreateFileW.argtypes = (
wintypes.LPCWSTR, # _In_ lpFileName
wintypes.DWORD, # _In_ dwDesiredAccess
wintypes.DWORD, # _In_ dwShareMode
LPSECURITY_ATTRIBUTES, # _In_opt_ lpSecurityAttributes
wintypes.DWORD, # _In_ dwCreationDisposition
wintypes.DWORD, # _In_ dwFlagsAndAttributes
wintypes.HANDLE) # _In_opt_ hTemplateFile
kernel32.CloseHandle.argtypes = (wintypes.HANDLE,)
kernel32.GetCommProperties.argtypes = (
wintypes.HANDLE, # _In_ hFile
LPCOMMPROP) # _Out_ lpCommProp
def get_comm_properties(handle_or_port):
if isinstance(handle_or_port, str):
handle = kernel32.CreateFileW(
handle_or_port,
GENERIC_READ | GENERIC_WRITE,
0, # exclusive access
None, # default security
OPEN_EXISTING,
0,
None)
if handle == INVALID_HANDLE_VALUE:
raise ctypes.WinError(ctypes.get_last_error())
close_handle = True
else:
handle = handle_or_port
close_handle = False
try:
prop = COMMPROP()
if not kernel32.GetCommProperties(handle, ctypes.byref(prop)):
raise ctypes.WinError(ctypes.get_last_error())
finally:
if close_handle:
kernel32.CloseHandle(handle)
return prop
<强>输出：
if __name__ == '__main__':
for i in range(1, 10):
port = r'\\.\COM%d' % i
try:
prop = get_comm_properties(port)
except WindowsError as e:
if e.winerror == ERROR_FILE_NOT_FOUND:
continue
print('%s properties' % port)
x = prop.dwMaxTxQueue if prop.dwMaxTxQueue else 'no limit'
print('\tMax output buffer size: %s' % x)
x = prop.dwMaxRxQueue if prop.dwMaxRxQueue else 'no limit'
print('\tMax input buffer size: %s' % x)
x = prop.dwCurrentTxQueue if prop.dwCurrentTxQueue else 'unavailable'
print('\tCurrent output buffer size: %s' % x)
x = prop.dwCurrentRxQueue if prop.dwCurrentRxQueue else 'unavailable'
print('\tCurrent input buffer size: %s' % x)
x = prop.max_baud if prop.max_baud else 'user programmable'
print('\tMax baud rate: %s' % x)
print('\tProvider subtypes:\n\t\t%s' %
'\n\t\t'.join(prop.prov_subtype))
print('\tProvider capabilities:\n\t\t%s' %
'\n\t\t'.join(prop.prov_capabilities))
print('\tSettable parameters:\n\t\t%s' %
'\n\t\t'.join(prop.settable_params))
print('\tSettable baud rates:\n\t\t%s' %
'\n\t\t'.join([str(x) for x in prop.settable_baud]))
print('\tSettable user baud rates: %s' %
prop.user_settable_baud)
print('\tSettable data bits:\n\t\t%s' %
'\n\t\t'.join([str(x) for x in prop.settable_data]))
print('\tSettable wide data bits: %s' %
prop.wide_settable_data)
print('\tSettable stop bits:\n\t\t%s' %
'\n\t\t'.join([str(x) for x in prop.settable_stop]))
print('\tSettable parity:\n\t\t%s' %
'\n\t\t'.join(prop.settable_parity))
答案 1 :(得分：1)
波特率＆lt; 100在Windows 7中被视为配置错误。因此，以50,75波特率启动循环将产生错误。 110波特不会返回错误。