Serial Transports

[chrisdutz]

I am currently rewriting Apache PLC4X from scratch. Part of that work is also rewriting the transports. The Serial transport is one of them. While it's easy to write tests for TCP and UDP transports for serial it's problematic. I stumbled over "socat" (Mac & Linux).

In my test-cases I am using that to sort of generate virtual serial ports and do IO via these ... possibly this could help with your work on Modbus RTU/ASCII (Again ... in PLC4X we also have support for those ... also doing Modbus RTU via TCP and stuff like that)

@BeforeEach
    void setUp() throws Exception {
        if (!System.getProperty("os.name").toLowerCase().contains("win")) {
            process = new ProcessBuilder("socat","-d","-d",
                "pty,raw,echo=0,link=/tmp/ttyV0",
                "pty,raw,echo=0,link=/tmp/ttyV1").start();
            // Give socat a moment to create links; optionally read its stderr for "N PTY is ..."
            Thread.sleep(500);
        }
   }


     ....

 @AfterEach
    void tearDown() throws Exception {
        if (process != null) {
            process.destroy();
        }
    }

Just thought I'd leave this here as you mentioned wanting to work on Modbus RTU.