Only one open connection can exist per SerialPort object. The best practice for any application is to wait for some amount of time after calling the Close method before attempting to call the Open method, as the port may not be closed instantly. SecurityPermission for calling unmanaged code. Jan 07, 2012 This site uses cookies for analytics, personalized content and ads. By continuing to browse this site, you agree to this use. I'm guessing your serial port's FIFO is limited to 16 bytes. Run receive before running send (perhaps you are - I can't tell). Modify receive to read more than one character (suggest 16 characters) at a time. Modify receive to linger after the last character for some small amount of time. Define an end-of-transmission mechanism.
- C Language Open Serial Port
- C++ Serial Port Write
- Serial Port Linux C Open Source
- C Code Open Serial Port
- C Open Com Port
- C Open Serial Port Windows
May 29, 2011 It appears that you are on Windows, Windows has API calls to open and control the serial port, and using the buffered input and output functions is usually not advised when dealing with the serial port. You may want to take a look at this link for Windows serial port communication.
Is there an easy way of programmatically checking if a serial COM port is already open/being used?
Normally I would use:
However, I would like to programatically check so I can attempt to use another COM port or some such.
Jon Seigel5 Answers
I needed something similar some time ago, to search for a device.
I obtained a list of available COM ports and then simply iterated over them, if it didn't throw an exception i tried to communicate with the device. A bit rough but working.
FionnFionnC Language Open Serial Port
The SerialPort class has an Open method, which will throw a few exceptions.The reference above contains detailed examples.
See also, the IsOpen property.
A simple test:
gimelgimelThis is what worked for me.
In Case You need to catch SerialPort (Open) Exceptions:https://docs.microsoft.com/en-us/dotnet/api/system.io.ports.serialport.open?view=netframework-4.7.2
You can try folloing code to check whether a port already open or not. I'm assumming you dont know specificaly which port you want to check.
Funky81Funky81Not the answer you're looking for? Browse other questions tagged c#.netserial-port or ask your own question.
-->Definition
C++ Serial Port Write
Exceptions
Access is denied to the port.
-or-
The current process, or another process on the system, already has the specified COM port open either by a SerialPort instance or in unmanaged code.
One or more of the properties for this instance are invalid. For example, the Parity, DataBits, or Handshake properties are not valid values; the BaudRate is less than or equal to zero; the ReadTimeout or WriteTimeout property is less than zero and is not InfiniteTimeout.
The port name does not begin with 'COM'.
-or-
The file type of the port is not supported.
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.
Serial Port Linux C Open Source
The specified port on the current instance of the SerialPort is already open.
Examples
The following code example demonstrates the use of the SerialPort class to allow two users to chat from two separate computers connected by a null modem cable. In this example, the users are prompted for the port settings and a username before chatting. This code example is part of a larger code example provided for the SerialPort class.
Remarks
Only one open connection can exist per SerialPort object.
The best practice for any application is to wait for some amount of time after calling the Close method before attempting to call the Open method, as the port may not be closed instantly.
C Code Open Serial Port
Security
C Open Com Port
SecurityPermission
for calling unmanaged code. Associated enumeration: UnmanagedCode Security action: LinkDemand