Read and write I/O

This article shows how to read and write the inputs and outputs of a Staubli CS8 or CS9 controller from a PC, in C# or Python. It gives a complete program that finds the I/O names, waits for an input and switches an output on, without any VAL 3 program on the controller.

Prerequisites

• The SDK is connected to the controller: see Connect to your robot.
• To write an output, the user of the connection has the right to write it.

Three calls

ReadIos and WriteIos take arrays: read or write several I/O in one request instead of one request per I/O.

Example

using UnderAutomation.Staubli;
using UnderAutomation.Staubli.Soap.Data;

public class HowToReadWriteIo
{
    static void Main()
    {
        
        var controller = new StaubliController();
        controller.Connect("192.168.0.254");

        // 1. Find the exact names of the I/O
        foreach (PhysicalIo io in controller.Soap.GetAllPhysicalIos())
            Console.WriteLine($"{io.Name} [{io.TypeStr}] {io.Description}");

        string input = @"BasicIO-1\%I0";
        string output = @"BasicIO-1\%Q0";

        // 2. Wait for the input, at most 10 seconds
        DateTime timeout = DateTime.Now.AddSeconds(10);
        while (controller.Soap.ReadIos(new[] { input })[0].Value == 0)
        {
            if (DateTime.Now > timeout) throw new TimeoutException($"{input} stayed off");
            Thread.Sleep(50);
        }

        // 3. Switch the output on, and check the answer of the controller
        PhysicalIoWriteResponse response = controller.Soap.WriteIos(new[] { output }, new[] { 1.0 })[0];
        if (!response.Found || !response.Success)
            Console.WriteLine($"Write of {output} failed: found={response.Found}");

        controller.Disconnect();
        
    }
}

The program:

1. prints the name of every I/O, to copy the exact names into the code;
2. reads the input every 50 ms until it is on, with a timeout of 10 s;
3. writes the output, and checks that the controller found it and accepted the value.

I/O names

A name contains the board and the I/O, separated by a backslash: BasicIO-1\%I0. The boards depend on the configuration of the controller, so the names of your cell can differ from the ones of this example. Always take them from GetAllPhysicalIos().

Write the backslash as it is: with a verbatim string in C# (@"BasicIO-1\%I0") and a raw string in Python (r"BasicIO-1\%I0").

Troubleshooting

• State is Undefined or InvalidName: the name does not exist on this controller. Compare it with the output of GetAllPhysicalIos(), including the case and the backslash.
• Found is true but Success is false: the controller refused the write. Check that the I/O is an output, and the rights of the user.
• The value changes back: a VAL 3 program writes the same output. Stop it, or agree on which side owns each output.

What to read next

• Inputs and outputs: the reference of the I/O methods.
• Monitor the state of the robot.