SerialToNetDotnet

A simple serial to telnet interfacing with multi-client support implemented in C#.NET

Features

• Multi-client support. A single device can be shared. (!) All clients receive the same echo, including remote editing, if available
• Cross-platform (Win, Linux, MacOS)
• Configurable serial port baudrate, databits, stopbits (not 1.5), parity bits
• Configurable tcp port for each serial port
• Supports telnet and raw connection options
  • In raw mode no telnet-specific commands are sent or processed
• Forwards data between serial port and network byte-by-byte
• Able to cut out specified symbols from net->serial stream - configurable
• Client identificator is asked to be used as signature
  • Prints already connected clients on connect event to see who is using the same port at the moment

Limitations

• No handshake support for serial port
• No support of 1.5 stopbits

Build

Visual studio

1. Open SerialToNetDotnet.sln with Visual Studio 2019. More recent should also work.
2. Right-click SerialToNetDotnet project, select Publish
3. Choose the publish profile for your target system, or create your own
4. Press Publish button
5. Your executables will be in the specified folder. Defaults are:
   • .\bin\Release\net5.0\publish\osx-x64 for MacOS
   • .\bin\Release\net5.0\publish\win64 for win64
   • .\bin\Release\net5.0\publish\linux-x64 for Linux x64

Command line

TDB

Usage

1. Copy executable file and libraries from publication folder into a directory. Files to copy:
   • Windows: SerialToNetDotnet.exe
   • Linux: libSystem.IO.Ports.Native.so, SerialToNetDotnet
   • MacOS: libSystem.IO.Ports.Native.dylib, SerialToNetDotnet
2. Create a YAML configuration file in the same directory as used for previous point. Use server_config.yaml as a reference
3. Run SerialToNetDotnet(.exe) with the path to configuration file. If nothing is specified, it will use server_config.yaml from the same directory as default.
4. Open a telnet connection to the host where the program is running. Use one of the ports specified in your config. This is tested only with Putty
   • Enter a short signature to be a recognizable client
5. When first client is connected, server tries to open the corresponding serial port. If it fails, a message is sent to client and to console
6. You can type status command into the program window to print the current status of opened ports and connected clients

TODO list

1. More self-functional Client (socket and send functions inside it)
2. Stability
   • Handle all errors from network and serial
   • Recover tcp servers and serial ports from erroneous states
3. Use async/await instead of callbacks
4. Test with other telnet clients

Acknowledgements

Inspired by ser2net. I did not find how to compile it for Windows and it does not have multiple clients support https://github.com/UngarMax/TelnetServer - used as reference for telnet server implementation