How to build an MCP Tool.

Scripts → Tutorials → Tutorial | Concept | How-to Guide | Reference

Step 1:

Create the MCP script

1. Navigate to

1. Scripts → Classes

2. Click in the create a New Class button

3. In Create new Code, select MCPTool

4. Click OK

Step 2: Edit the Script

In the Script code, you can have multiple methods and they follow this format:

[McpServerTool, Description("<This is the question>")]
public string <MethodName> (
[Description("<Description of the parameter>")] <Parameters>)
{
	<Logic>

    <Return>
}

Example:

[McpServerTool, Description("Performs concatenation of two input text values.")]
public string Concat(
	[Description("The first text value to be used in the operation.")] string parameter1,
	[Description("The second text value to be used in the operation, concatenated after the first.")] string parameter2)
{
	return parameter1 + parameter2;
}

The logic can process the data and return it as a string, so the AI will receive it.

Step 3: Configure Claude AI

1. Have Claude AI Desktop downloaded

2. Go in Settings → Developer → Edit Config and select the ”claude_desktop_config.json”

3. This .json should have the following content:

   Code Block
   { "mcpServers": { "<SolutionName>": { "command": "<ProductPath>\\fx-10\\net8.0\\TMCPServerStdio\\TMCPServerStdio.exe", "args": [ "/host:127.0.0.1", "/port:<port>" ], "transport": "stdio" } } }

   
   

4. In the Developer setting it shoud show “running” and when you open a new chat in “Search and Tools” you will see the name of your solution there.

Step 4: Query in Claude AI

You can query any method in a Claude chat. e.g: “What is the tag value?” and it returns the value requested.

Besides the method you created in the script, you can ask general information about the solution, like:

• Get tag historian

• Get alarm online

• Get value

Step 2: Create KPI Calculator Class

1. Go to Scripts → Classes
2. Create class: KPICalculator
3. Configure as standard Methods class

csharp

public double CalculateOEE(double availability, double performance, double quality)
{
    return availability * performance * quality * 100;
}

public double GetAverageProduction(DateTime startTime, DateTime endTime)
{
    // Calculate average production rate over period
    double totalProduction = @Tag.TotalUnits;
    double hours = (endTime - startTime).TotalHours;
    return hours > 0 ? totalProduction / hours : 0;
}

public string GetProductionStatus()
{
    if (@Tag.ProductionRate > 100)
        return "High Performance";
    else if (@Tag.ProductionRate > 80)
        return "Normal";
    else
        return "Below Target";
}

Step 3: Create MCP Tool Class

1. Create new class: ProductionMCPTool
2. Select MCP Tool type
3. Add decorated methods:

csharp

[MCPMethod(Description = "Get current production KPIs")]
public object GetCurrentKPIs()
{
    return new {
        ProductionRate = @Tag.ProductionRate,
        Efficiency = @Tag.Efficiency,
        OEE = @Script.Class.KPICalculator.CalculateOEE(
            @Tag.Availability, @Tag.Performance, @Tag.Quality),
        Status = @Script.Class.KPICalculator.GetProductionStatus(),
        Timestamp = DateTime.Now
    };
}

[MCPMethod(Description = "Get production history for specified hours")]
public object GetProductionHistory(
    [MCPParameter(Description = "Hours to look back")] int hours)
{
    var endTime = DateTime.Now;
    var startTime = endTime.AddHours(-hours);
    
    // Query historian
    var data = @Historian.Table.ProductionData.GetData(startTime, endTime);
    
    return new {
        Period = $"Last {hours} hours",
        AverageRate = @Script.Class.KPICalculator.GetAverageProduction(startTime, endTime),
        TotalUnits = @Tag.TotalUnits,
        DataPoints = data.Rows.Count
    };
}

[MCPMethod(Description = "Analyze production trend")]
public string AnalyzeProductionTrend(
    [MCPParameter(Description = "Time period in hours")] int periodHours)
{
    var current = @Tag.ProductionRate;
    var average = @Script.Class.KPICalculator.GetAverageProduction(
        DateTime.Now.AddHours(-periodHours), DateTime.Now);
    
    if (current > average * 1.1)
        return "Trending Up - Production improving";
    else if (current < average * 0.9)
        return "Trending Down - Requires attention";
    else
        return "Stable - Within normal range";
}

Step 4: Test MCP Tool

1. Start runtime
2. Verify KPIs calculating
3. Check historian data collection
4. Test with AI assistant:
   • "What are the current production KPIs?"
   • "Show me production history for last 8 hours"
   • "Analyze the production trend"

Next Steps

These tutorials provide simple, practical starting points for both MCP Tools

focusing on real industrial scenarios while keeping complexity minimal for learning purposes.

In this section...