Serial Port Parity

The port is in an invalid state.or-An attempt to set the state of the underlying port failed. For example, the parameters passed from this SerialPort object were invalid. Implement a serial port read loop and dispatch to a Protocol instance (like the asyncio.Protocol) but do it with threads. Calls to close will close the serial port but it is also possible to just stop this thread and continue to use the serial port instance otherwise. init (serialinstance, protocolfactory) ¶.

Library

Instrument Control Toolbox

Description

The Serial Configuration block configures parameters for a serialport that you can use to send and receive data. You must set the parametersof your serial port before you set up the Serial Receive and the SerialSend block.

You must first specify the configuration of your serial portbefore you configure the Serial Receive and Serial Send blocks. TheReceive and Send blocks will prompt you to add a Configuration blockto configure your serial port properties.

Note

You need a license for both the Instrument Control Toolbox™ and Simulink^® softwareto use this block.

Parameters

Communication port

Specify the serial port to configure. You have to select anavailable port from the list. By default no port is selected and thisfield displays <Please select a port...>.Use this configured port in your Serial Send and SerialReceive blocks. Each Serial Send and Receive block must havea configured serial configuration. If you use multiple serial portsin your simulation, you must configure each port using a separateserial configuration block.

Baud rate

Specify the rate at which bits are transmitted for the serialinterface. Default value is 9600.

Data bits

Specify the number of data bits to transmit over the serialinterface. Default value is 8 and other availablevalues are 5, 6, and 7.

Parity

Specify how you want to check parity bits in the data bits transmittedvia the serial port. By default this is set to none,and the available values are:

none — Where no paritychecking is done.
even — Where parity bitis set to 0 if the number of ones in a given set of bits is even.
odd — Where parity bitis set to 1 if the number of ones in a given set of bits is odd.
mark — Where parity bitis always set to 1.
space — Where parity bitis always set to 0.

Stop bits

Specify the number of bits used to indicate the end of a byte.The number of data bits you select determines the choices availablefor stop bits. If you select data bits 6, 7,or 8, then the default value is 1 andthe other available choice is 2. If you selectdata bit 5, then the only choice available is 1.5.

Byte order

Specify the byte order as littleEndian (default)or bigEndian. If byte order is littleEndian,then the instrument stores the first byte in the first memory address.If byte order is bigEndian, then the instrumentstores the last byte in the first memory address.

You should configure byte order to the appropriate value foryour instrument before performing a read or write operation. Referto your instrument documentation for information about the order inwhich it stores bytes.

Flow control

Specify the process of managing the rate of data transmissionon your serial port. Choose none to have no flowcontrol or hardware to let your hardware determinethe flow control.

Timeout

Specify the amount of time that the model will wait for thedata during each simulation time step. The default value is 10 (seconds).

Opening serial ports¶

Open port at “9600,8,N,1”, no timeout:

Open named port at “19200,8,N,1”, 1s timeout:

Open port at “38400,8,E,1”, non blocking HW handshaking:

Configuring ports later¶

Get a Serial instance and configure/open it later:

Also supported with context manager:

Readline¶

Be careful when using readline(). Do specify a timeout when opening theserial port otherwise it could block forever if no newline character isreceived. Also note that readlines() only works with a timeout.readlines() depends on having a timeout and interprets that as EOF (endof file). It raises an exception if the port is not opened correctly.

Do also have a look at the example files in the examples directory in thesource distribution or online.

Note

The eol parameter for readline() is no longer supported whenpySerial is run with newer Python versions (V2.6+) where the moduleio is available.

EOL¶

To specify the EOL character for readline() or to use universal newlinemode, it is advised to use io.TextIOWrapper:

Testing ports¶

Listing ports¶

Linux Serial Port Parity

python-mserial.tools.list_ports will print a list of available ports. Itis also possible to add a regexp as first argument and the list will onlyinclude entries that matched.

Note