Python Serial Read Timeout Example

15-09-2021
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  1. A key parameter in the pyserial Serial class is the timeout parameter. This parameter is defined as: timeout=None, #set a timeout value, None for waiting forever. The Serial class read function also accepts a size parameter that indicates how many characters should be read. Below is the source for the read function on Posix systems (Linux, etc).
  2. To read single byte from serial device. Data = ser.read to read given number of bytes from the serial device. Data = ser.read(size=5) to read one line from serial device. Data = ser.readline to read the data from serial device while something is being written over it. #for python2.7 data = ser.read(ser.inWaiting) #for python3 ser.read(ser.
  3. The following are 13 code examples for showing how to use System.TimeoutException.These examples are extracted from open source projects. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example.

Bases: object

Instantiate a Serial object and open the tty device at the specifiedpath with the specified baudrate, and the defaults of 8 data bits, noparity, 1 stop bit, no software flow control (xonxoff), and no hardwareflow control (rtscts).

Parameters:
  • devpath (str) – tty device path.
  • baudrate (int) – baudrate.
  • databits (int) – data bits, can be 5, 6, 7, 8.
  • parity (str) – parity, can be “none”, “even”, “odd”.
  • stopbits (int) – stop bits, can be 1 or 2.
  • xonxoff (bool) – software flow control.
  • rtscts (bool) – hardware flow control.
Returns:

Serial object.

Return type:
Raises:
  • SerialError – if an I/O or OS error occurs.
  • TypeError – if devpath, baudrate, databits, parity, stopbits, xonxoff, or rtscts types are invalid.
  • ValueError – if baudrate, databits, parity, or stopbits values are invalid.

Python Serial.getTimeout - 1 examples found. These are the top rated real world Python examples of serial.Serial.getTimeout extracted from open source projects. You can rate examples to help us improve the quality of examples.

read(length, timeout=None)[source]

Read up to length number of bytes from the serial port with anoptional timeout.

timeout can be positive for a blocking read with a timeout inseconds, zero for a non-blocking read, or negative or None for ablocking read that will block until length number of bytes are read.Default is a blocking read.

For a non-blocking or timeout-bound read, read() may return less thanthe requested number of bytes.

For a blocking read with the VMIN setting configured, read() willblock until at least VMIN bytes are read. For a blocking read with bothVMIN and VTIME settings configured, read() will block until at leastVMIN bytes are read or the VTIME interbyte timeout expires after thelast byte read. In either case, read() may return less than therequested number of bytes.

Parameters:
  • length (int) – length in bytes.
  • timeout (int, float, None) – timeout duration in seconds.
Returns:

data read.

Return type:

bytes

Raises:

SerialError – if an I/O or OS error occurs.

write(data)[source]

Write data to the serial port and return the number of byteswritten.

Parameters:

data (bytes, bytearray, list) – a byte array or list of 8-bit integers to write.

Returns:

number of bytes written.

Return type:

int

Raises:
  • SerialError – if an I/O or OS error occurs.
  • TypeError – if data type is invalid.
  • ValueError – if data is not valid bytes.
poll(timeout=None)[source]

Poll for data available for reading from the serial port with anoptional timeout.

timeout can be positive for a timeout in seconds, zero for anon-blocking poll, or negative or None for a blocking poll. Default isa blocking poll.

Parameters:timeout (int, float, None) – timeout duration in seconds.
Returns:True if data is available for reading from the serial port, False if not.
Return type:bool
flush()[source]

Flush the write buffer of the serial port, blocking until all bytesare written.

Raises:SerialError – if an I/O or OS error occurs.
input_waiting()[source]
Pyserial read timeout

Query the number of bytes waiting to be read from the serial port.

Returns:number of bytes waiting to be read.
Return type:int
Raises:SerialError – if an I/O or OS error occurs.
output_waiting()[source]

Query the number of bytes waiting to be written to the serial port.

Returns:number of bytes waiting to be written.
Return type:int
Raises:SerialError – if an I/O or OS error occurs.
close()[source]

Close the tty device.

Raises:SerialError – if an I/O or OS error occurs.
fd

Get the file descriptor of the underlying tty device.

Type:int
devpath

Get the device path of the underlying tty device.

Type:str
baudrate

Get or set the baudrate.

Raises:
  • SerialError – if an I/O or OS error occurs.
  • TypeError – if baudrate type is not int.
  • ValueError – if baudrate value is not supported.
Type:

int

databits

Get or set the data bits. Can be 5, 6, 7, 8.

Raises:
  • SerialError – if an I/O or OS error occurs.
  • TypeError – if databits type is not int.
  • ValueError – if databits value is invalid.
Type:

int

Python Serial Read Time Out Example Pdf

parity

Get or set the parity. Can be “none”, “even”, “odd”.

Raises:
  • SerialError – if an I/O or OS error occurs.
  • TypeError – if parity type is not str.
  • ValueError – if parity value is invalid.
Type:

str

Python Serial Read Time Out Examples

stopbits

Get or set the stop bits. Can be 1 or 2.

Raises:
  • SerialError – if an I/O or OS error occurs.
  • TypeError – if stopbits type is not int.
  • ValueError – if stopbits value is invalid.
Type:

int

xonxoff

Get or set software flow control.

Raises:
  • SerialError – if an I/O or OS error occurs.
  • TypeError – if xonxoff type is not bool.
Type:

bool

rtscts

Get or set hardware flow control.

Raises:
  • SerialError – if an I/O or OS error occurs.
  • TypeError – if rtscts type is not bool.
Type:

bool

vmin

Get or set the VMIN termios setting for minimum number of bytes returnedfrom a blocking read. Can be between 0 and 255.

When configured in conjunction with VTIME, VTIME acts as an interbytetimeout that restarts on every byte received, and a blocking read willblock until at least VMIN bytes are read or the VTIME timeout expires afterthe last byte read. See the termios man page for more information.

Raises:
  • SerialError – if an I/O or OS error occurs.
  • TypeError – if vmin type is not int.
  • ValueError – if vmin value is invalid.
Type:

int

vtime

Get or set the VTIME termios setting for timeout in seconds of ablocking read. Can be between 0 to 25.5 seconds, with a resolution of 0.1seconds.

When configured in conjunction with VMIN, VTIME acts as an interbytetimeout that restarts on every byte received, and a blocking read willblock until at least VMIN bytes are read or the VTIME timeout expires afterthe last byte read. See the termios man page for more information.

Raises:
  • SerialError – if an I/O or OS error occurs.
  • TypeError – if vtime type is not float or int.
  • ValueError – if vtime value is invalid.
Type:

float

Bases: object

Instantiate a Serial object and open the tty device at the specifiedpath with the specified baudrate, and the defaults of 8 data bits, noparity, 1 stop bit, no software flow control (xonxoff), and no hardwareflow control (rtscts).

Parameters:
  • devpath (str) – tty device path.
  • baudrate (int) – baudrate.
  • databits (int) – data bits, can be 5, 6, 7, 8.
  • parity (str) – parity, can be “none”, “even”, “odd”.
  • stopbits (int) – stop bits, can be 1 or 2.
  • xonxoff (bool) – software flow control.
  • rtscts (bool) – hardware flow control.
Returns:

Serial object.

Return type:
Raises:
  • SerialError – if an I/O or OS error occurs.
  • TypeError – if devpath, baudrate, databits, parity, stopbits, xonxoff, or rtscts types are invalid.
  • ValueError – if baudrate, databits, parity, or stopbits values are invalid.
read(length, timeout=None)[source]

Read up to length number of bytes from the serial port with anoptional timeout.

timeout can be positive for a timeout in seconds, 0 for anon-blocking read, or negative or None for a blocking read that willblock until length number of bytes are read. Default is a blockingread.

For a non-blocking or timeout-bound read, read() may return data whoselength is less than or equal to the requested length.

Parameters:
  • length (int) – length in bytes.
  • timeout (int, float, None) – timeout duration in seconds.
Returns:

data read.

Return type:

bytes

Raises:

SerialError – if an I/O or OS error occurs.

write(data)[source]

Write data to the serial port and return the number of byteswritten.

Parameters:

data (bytes, bytearray, list) – a byte array or list of 8-bit integers to write.

Returns:

number of bytes written.

Return type:

int

Raises:
  • SerialError – if an I/O or OS error occurs.
  • TypeError – if data type is invalid.
  • ValueError – if data is not valid bytes.

Python Read Serial Port

poll(timeout=None)[source]

Poll for data available for reading from the serial port.

timeout can be positive for a timeout in seconds, 0 for anon-blocking poll, or negative or None for a blocking poll. Default isa blocking poll.

Parameters:timeout (int, float, None) – timeout duration in seconds.
Returns:True if data is available for reading from the serial port, False if not.
Return type:bool
flush()[source]

Flush the write buffer of the serial port, blocking until all bytesare written.

Raises:SerialError – if an I/O or OS error occurs.
input_waiting()[source]

Query the number of bytes waiting to be read from the serial port.

Timeout
Returns:number of bytes waiting to be read.
Return type:int
Raises:SerialError – if an I/O or OS error occurs.

Python Pyserial Read Example

output_waiting()[source]

Query the number of bytes waiting to be written to the serial port.

Returns:number of bytes waiting to be written.
Return type:int
Raises:SerialError – if an I/O or OS error occurs.
Python serial read time out example sentences
close()[source]

Close the tty device.

Raises:SerialError – if an I/O or OS error occurs.
fd

Get the file descriptor of the underlying tty device.

Type:int
devpath

Get the device path of the underlying tty device.

Type:str
baudrate

Get or set the baudrate.

Raises:
  • SerialError – if an I/O or OS error occurs.
  • TypeError – if baudrate type is not int.
  • ValueError – if baudrate value is not supported.
Type:

int

databits

Get or set the data bits. Can be 5, 6, 7, 8.

Raises:
  • SerialError – if an I/O or OS error occurs.
  • TypeError – if databits type is not int.
  • ValueError – if databits value is invalid.
Type:

int

parity

Get or set the parity. Can be “none”, “even”, “odd”.

Raises:
  • SerialError – if an I/O or OS error occurs.
  • TypeError – if parity type is not str.
  • ValueError – if parity value is invalid.
Type:

str

stopbits

Python Serial Read Time Out Example Sentences

Get or set the stop bits. Can be 1 or 2.

Python Serial Read Timeout Example
Raises:
  • SerialError – if an I/O or OS error occurs.
  • TypeError – if stopbits type is not int.
  • ValueError – if stopbits value is invalid.
Type:

int

xonxoff

Get or set software flow control.

Raises:
  • SerialError – if an I/O or OS error occurs.
  • TypeError – if xonxoff type is not bool.
Type:

bool

rtscts

Get or set hardware flow control.

Raises:
  • SerialError – if an I/O or OS error occurs.
  • TypeError – if rtscts type is not bool.
Type:

bool