How to build an MCP Tool

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

Step 1: Configure Historian

1. Navigate to Historian → Tables
2. Create table: ProductionData
3. Add tags:
   • Tag.ProductionRate
   • Tag.Efficiency
   • Tag.QualityScore
   • Tag.DowntimeMinutes
4. Set scan rate: 60 seconds
5. Enable storage

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

• Advanced MCP Tools → Complex multi-tool scenarios
• ML.NET Models → Regression and classification
• Edge Computing → Deploy to field devices

These tutorials provide simple, practical starting points for both MCP Tools and ML.NET integration, focusing on real industrial scenarios while keeping complexity minimal for learning purposes.

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