Accessing Watchport/H through ASCII commands

How do I go about doing this? In a C# program I created a serial port and opened it successfully, but when I send the ASCII command to the com port I get nothing back (when using ReadExisting in C#). When I use “ReadLine” function in C# my app bombs.

I’m unsure whether or not I’m supposed to be using the c# serial port object or some other object to read this data, since the documentation says “ASCII command interface” - not sure what that means.

I’m opening the port like so…

       // Set the properties.
        port.PortName = "COM" + portnum;
        port.BaudRate = 9600;
        port.Parity = Parity.None;
        port.StopBits = StopBits.One;

        // Set the read/write timeouts
        port.ReadTimeout = 300;
        port.WriteTimeout = 300;
        port.DtrEnable = true;
        //open the port

Then trying to write & read like so…

        //pause for a little and let the serial port catch up
        returntemp = port.ReadLine();


ASCII command interface just means you can send specific ascii characters to the sensors and expect a certain behavior back from them.

You may want to verify that you can get a response back from the H sensor at all by not using your program and trying something like Hyperterminal. Just open up a connection directly to the com port that has been assigned to the sensor and hit ? . see if you get a response back or not.

That would at least tell us the port is opening ok and that it’s responding.