Displays Units Conversion Reference

Displays →  Tutorial | Concept | How-to Guide | ISA-101 | Reference

Configuration Steps

1. Set Tag Units
   • Navigate to Unified Namespace → Tags
   • Configure Units property for each tag
   • Or set via script: @Tag.Temperature.Units = "°C"
2. Apply Conversion Table
   • Assign conversion table to client
   • Set @Client.Units = "MetricToImperial"
   • Values automatically convert
3. Display Converted Units
   • Use @Tag.Temperature.DisplayUnits
   • Shows converted unit string
   • Updates with conversion changes

Conversion Table Properties

Conversion Formula

NewValue = (BaseValue / Div) + Add

Standard Conversions

Temperature

Length

Pressure

Runtime Usage

Client-Side Configuration

csharp

// Set conversion table for client
@Client.Units = "MetricToImperial";

// Check current conversion
string currentTable = @Client.Units;

// Remove conversion
@Client.Units = "";

Tag Properties

csharp

// Original unit
string baseUnit = @Tag.Pressure.Units;  // "bar"

// Converted unit (after conversion applied)
string displayUnit = @Tag.Pressure.DisplayUnits;  // "psi"

// Original value
double baseValue = @Tag.Pressure.BaseValue;  // 10 bar

// Converted value
double displayValue = @Tag.Pressure.Value;  // 145.04 psi

Creating Custom Tables

1. Navigate to Displays → Units Conversion
2. Create new conversion set
3. Define conversions:
   • BaseUnit and NewUnit
   • Div and Add factors
   • MeasurementType category

Example: Custom Speed Conversion

BaseUnit: m/s
NewUnit: km/h
Div: 0.278
Add: 0
MeasurementType: Speed

Multi-Client Scenarios

Different Units Per Client

csharp

// Client 1 - US Operator
@Client.Units = "ImperialUnits";
// Sees: 72°F, 14.7 psi, 100 ft

// Client 2 - EU Operator  
@Client.Units = "MetricUnits";
// Sees: 22.2°C, 1.01 bar, 30.5 m

// Server stores single value set
// Each client sees converted display

Best Practices

1. Define Units Early - Set during tag creation
2. Group by Type - Organize conversions by measurement
3. Test Conversions - Verify accuracy
4. Document Custom - Explain custom conversions
5. Consider Precision - Account for rounding
6. Default Tables - Provide standard sets
7. User Preferences - Store per operator

Measurement Types

Organize conversions by category:

• Temperature - °C, °F, K
• Pressure - bar, psi, kPa, MPa
• Flow - m³/h, gpm, l/s
• Length - m, ft, km, mi
• Mass - kg, lb, ton
• Volume - l, gal, m³
• Speed - m/s, km/h, mph
• Energy - kWh, BTU, J

Troubleshooting

Values not converting:

• Check Units property set on tag
• Verify conversion table assigned
• Confirm table contains unit mapping
• Review Div/Add factors

Wrong conversion:

• Check formula factors
• Verify unit strings match exactly
• Test with known values
• Review calculation order

Client differences:

• Confirm each client's Units setting
• Check local vs server values
• Verify table assignments
• Test client isolation

Examples

Temperature Gauge

xml

<TextBlock Text="{Tag.Temperature.Value}" />
<TextBlock Text="{Tag.Temperature.DisplayUnits}" />
<!-- Shows: "72" and "°F" for Imperial client -->

Dynamic Switching

csharp

public void ToggleUnits()
{
    if (@Client.Units == "MetricToImperial")
        @Client.Units = "";
    else
        @Client.Units = "MetricToImperial";
}

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