---
source_files:
  - Common/DTS.Common.DAS.Concepts/Test/Module/Channel/Sensor/SensorUnits.cs
  - Common/DTS.Common.DAS.Concepts/Test/Module/Channel/Sensor/ExcitationVoltage.cs
generated_at: "2026-04-16T11:39:55.789807+00:00"
model: "zai-org/GLM-5-FP8"
schema_version: 1
sha256: "00bbefe8072cdb62"
---

# Documentation: Test.Module.Channel.Sensor

## 1. Purpose

This module defines sensor-related concepts within the DAS (Data Acquisition System) domain model. Specifically, it provides an enumeration for sensitivity unit types (`SensUnits`) and utility methods for converting between excitation voltage enum values and their numeric magnitudes. The module is part of a larger nested class hierarchy representing test configuration concepts for channel/sensor setup.

## 2. Public Interface

### Enum: `Test.Module.Channel.Sensor.SensUnits`

Defines all available sensitivity unit types for sensor configuration.

| Member | Value | Description Attribute | Purpose |
|--------|-------|----------------------|---------|
| `NONE` | 0 | "NONE" | No Sensitivity Units (Polynomial Sensor) |
| `mV` | 1 | "mV" | Sensitivity expressed in mV with output at Capacity EU |
| `mVperV` | 2 | "mV/V" | Excitation proportional sensitivity expressed in mV/V with output at Capacity EU |
| `mVperVperEU` | 3 | "mV/V/EU" | Excitation proportional sensitivity expressed in mV/V/EU |
| `mVperEU` | 4 | "mV/EU" | Sensitivity expressed in mV/EU |

---

### Method: `GetExcitationVoltageMagnitudeFromEnum`

**Signature:**
```csharp
public static double GetExcitationVoltageMagnitudeFromEnum(
    ExcitationVoltageOptions.ExcitationVoltageOption target)
```

**Behavior:** Converts an `ExcitationVoltageOptions.ExcitationVoltageOption` enum value to its associated numeric voltage magnitude (in volts) using a `VoltageMagnitudeAttributeCoder`. Throws `ArgumentException` if the conversion fails.

---

### Method: `GetExcitationVoltageEnumFromMagnitude`

**Signature:**
```csharp
public static ExcitationVoltageOptions.ExcitationVoltageOption GetExcitationVoltageEnumFromMagnitude(
    double magnitude)
```

**Behavior:** Converts a numeric voltage magnitude to the corresponding `ExcitationVoltageOptions.ExcitationVoltageOption` enum value. On failure, logs the exception via `APILogger.Log` and returns `ExcitationVoltageOptions.ExcitationVoltageOption.Undefined` rather than throwing.

## 3. Invariants

- The `SensUnits` enum values are explicitly assigned sequential integers starting at 0.
- The `Module` class is declared `sealed`, preventing further inheritance.
- The `ExcitationVoltageOptions.ExcitationVoltageOption` type (defined externally in `DTS.Common.Enums`) is expected to have an associated `VoltageMagnitudeAttribute` for each enum member that these methods can decode/encode.
- The two conversion methods have asymmetric error handling: `GetExcitationVoltageMagnitudeFromEnum` throws on failure, while `GetExcitationVoltageEnumFromMagnitude` returns `Undefined` and logs.

## 4. Dependencies

### This module depends on:
- `System` - Core .NET types
- `System.ComponentModel` - `DescriptionAttribute` used on enum members
- `DTS.Common.Enums` - Provides `ExcitationVoltageOptions.ExcitationVoltageOption` and `ExcitationVoltageOptions.VoltageMagnitudeAttributeCoder`
- `DTS.Common.Utilities` - Likely provides the base `AttributeCoder<TEnum, TAttribute, TValue>` pattern (inferred from usage)
- `DTS.Common.Utilities.Logging` - Provides `APILogger` for error logging

### What depends on this module:
- Cannot be determined from source alone. The partial class structure suggests other files extend `Test`, `Test.Module`, `Test.Module.Channel`, and `Test.Module.Channel.Sensor`.

## 5. Gotchas

1. **Commented-out code suggests refactoring:** The `ExcitationVoltage.cs` file contains a fully commented-out `ExcitationVoltageOption` enum and related classes (`VoltageMagnitudeAttribute`, `VoltageMagnitudeAttributeCoder`). The active methods reference `ExcitationVoltageOptions.ExcitationVoltageOption` from `DTS.Common.Enums`, indicating this functionality was moved to a different namespace. The commented code may cause confusion about where the enum is actually defined.

2. **Asymmetric error handling:** The two conversion methods handle errors differently. `GetExcitationVoltageMagnitudeFromEnum` throws an `ArgumentException` (wrapping the inner exception), while `GetExcitationVoltageEnumFromMagnitude` silently logs and returns `Undefined`. Callers must handle both throwing and non-throwing failure modes.

3. **Partial class structure:** The `Test`, `Module`, `Channel`, and `Sensor` classes are all partial, spread across multiple files (indicated by comments like `// *** see Test.cs ***`). The full API surface requires examining all partial file definitions.