---
source_files:
  - DataPRO/Modules/PreviousDBVersions/Version57/DatabaseExport/DASConcepts/Test.Module.Channel.Sensor.Bridge.cs
  - DataPRO/Modules/PreviousDBVersions/Version57/DatabaseExport/DASConcepts/Test.Module.Channel.Sensor.SensorUnits.cs
  - DataPRO/Modules/PreviousDBVersions/Version57/DatabaseExport/DASConcepts/Test.Module.Channel.Sensor.ZeroMethod.cs
  - DataPRO/Modules/PreviousDBVersions/Version57/DatabaseExport/DASConcepts/DigitalInputScaleMultiplier.cs
  - DataPRO/Modules/PreviousDBVersions/Version57/DatabaseExport/DASConcepts/Test.Module.Channel.Sensor.ExcitationVoltage.cs
  - DataPRO/Modules/PreviousDBVersions/Version57/DatabaseExport/DASConcepts/InitialOffset.cs
  - DataPRO/Modules/PreviousDBVersions/Version57/DatabaseExport/DASConcepts/LinearizationFormula.cs
generated_at: "2026-04-16T04:57:48.606656+00:00"
model: "Qwen/Qwen3-Coder-Next-FP8"
schema_version: 1
sha256: "af9c7b6d258fe03e"
---

# Documentation: DAS Sensor Concepts (Version 57)

## 1. Purpose

This module defines core enumerations and data structures used to configure and process sensor data within the DTS DAS (Data Acquisition System) framework, specifically for database export in Version 57. It provides type-safe representations of sensor bridge configurations, sensitivity units, zeroing methods, excitation voltages, and linearization formulas—enabling consistent interpretation of sensor metadata across data import, processing, and export pipelines. These constructs serve as a bridge between legacy database formats and current system logic, preserving historical behavior while supporting extensibility.

## 2. Public Interface

### Nested Enumerations (within `DatabaseExport.Test.Module.Channel.Sensor`)

#### `BridgeType`
- **Definition**: `public enum BridgeType`
- **Values**:
  - `IEPE = 1 << 0` — Sensor uses IEPE (Integrated Electronics Piezo-Electric) setup.
  - `QuarterBridge = 1 << 1` — Sensor uses quarter-bridge configuration.
  - `HalfBridge = 1 << 2` — Sensor uses half-bridge configuration.
  - `FullBridge = 1 << 3` — Sensor uses full-bridge configuration.
  - `DigitalInput = 1 << 4` — Sensor acts as a digital input.
  - `SQUIB = 1 << 5` — Sensor uses SQUIB (a proprietary DTS technology).
  - `TOMDigital = 1 << 6` — TOM digital input mode.
- **Behavior**: Bitwise flags; intended for combination via OR operations.

#### `SensUnits`
- **Definition**: `public enum SensUnits`
- **Values**:
  - `NONE = 0` — No sensitivity units (used for polynomial sensors).
  - `mV = 1` — Sensitivity in millivolts at full-scale (Capacity EU).
  - `mVperV = 2` — Excitation-proportional sensitivity in mV/V at full-scale.
  - `mVperVperEU = 3` — Sensitivity in mV/V per Engineering Unit.
  - `mVperEU = 4` — Sensitivity in mV per Engineering Unit.
- **Behavior**: Represents sensitivity unit types for sensor calibration.

#### `ZeroMethodType`
- **Definition**: `public enum ZeroMethodType`
- **Values**:
  - `AverageOverTime = 0` — Electrical zero calculated as average over time.
  - `UsePreEventDiagnosticsZero = 1` — Zero calculated using pre-event diagnostics.
  - `None = 2` — Zero set via absolute/injected value.
- **Notes**: Order and values are preserved for legacy compatibility (e.g., GM ISF import).

#### `OriginalZeroMethodType`
- **Definition**: `public enum OriginalZeroMethodType`
- **Values**:
  - `AverageOverTime` — Same as `ZeroMethodType.AverageOverTime`.
  - `UsePreCalZero` — Zero calculated using pre-calibration diagnostics.
  - `None` — Same as `ZeroMethodType.None`.
- **Notes**: Distinct from `ZeroMethodType` to preserve original enum values during migration; `UsePreCalZero` maps to `UsePreEventDiagnosticsZero` semantically.

#### `ExcitationVoltageOption`
- **Definition**: `public enum ExcitationVoltageOption`
- **Values**:
  - `Undefined = 1` — Voltage magnitude 0.0 V.
  - `Volt2 = 2` — 2.0 V.
  - `Volt2_5 = 4` — 2.5 V.
  - `Volt3 = 8` — 3.0 V.
  - `Volt5 = 16` — 5.0 V.
  - `Volt10 = 32` — 10.0 V.
  - `Volt1 = 64` — 1.0 V.
- **Behavior**: Bitwise flags (powers of two); values are *not* sequential.

#### `DigitalInputScaleMultiplier.InputModes`
- **Definition**: `public enum InputModes`
- **Values**:
  - `TLH = 1 << 1` — Transition Low-to-High.
  - `THL = 1 << 2` — Transition High-to-Low.
  - `CCNO = 1 << 3` — Contact Closure, Normally Open.
  - `CCNC = 1 << 4` — Contact Closure, Normally Closed.

#### `DigitalInputScaleMultiplier.Forms`
- **Definition**: `public enum Forms`
- **Values**:
  - `ArbitraryLowAndHigh` — Only supported form; maps digital 0/1 to configurable `DefaultValue`/`ActiveValue`.

### Public Classes

#### `DigitalInputScaleMultiplier`
- **Namespace**: `DatabaseExport`
- **Properties**:
  - `Form` (`Forms`) — Format of the scale multiplier; currently only `ArbitraryLowAndHigh`.
  - `DefaultValue` (`double`) — Value displayed for digital input `0` (OFF).
  - `ActiveValue` (`double`) — Value displayed for digital input `1` (ON); defaults to `1.0`.
- **Constructors**:
  - `DigitalInputScaleMultiplier()` — Initializes with `DefaultValue = 0.0`, `ActiveValue = 1.0`.
  - `DigitalInputScaleMultiplier(DigitalInputScaleMultiplier copy)` — Copy constructor.
- **Methods**:
  - `string ToSerializeDbString()` — Serializes to `"ArbitraryLowAndHigh{sep}DefaultValue{sep}ActiveValue"` using invariant culture list separator.
  - `void FromDbSerializeString(string s)` — **Currently unimplemented** (body commented out). Returns early if `s == null`.

#### `InitialOffset`
- **Namespace**: `DatabaseExport`
- **Properties**:
  - `Form` (`InitialOffset.Forms`) — Format: `None`, `EU`, or `EUAtMV`.
  - `EU` (`double`) — Offset in Engineering Units (used for `EU` and `EUAtMV` forms).
  - `MV` (`double`) — Millivolt value at which `EU` is observed (used only for `EUAtMV` form).
- **Constructors**:
  - `InitialOffset()` — Initializes with `Form = None`, `EU = 0`, `MV = 0`.
  - `InitialOffset(InitialOffset copy)` — Copy constructor.
- **Methods**:
  - `string ToDbSerializeString()` — Serializes to `"Form{sep}EU{sep}MV"`.
  - `void FromDbSerializeString(string input)` — Parses serialized string; throws `InvalidDataException`/`FormatException` on malformed input.

#### `LinearizationFormula`
- **Namespace**: `DatabaseExport`
- **Properties**:
  - `Style` (`LinearizationFormula.Styles`) — Linearization method; defaults to `IRTraccDiagnosticsZero`.
  - `PolynomialSensitivity` (`double`) — Sensitivity factor for polynomial scaling; defaults to `1.0`.
  - `LinearizationExponent` (`double`) — Exponent used in power-law linearization; defaults to `1.0`.
  - `MMPerV` (`double`) — Millimeters per volt (slope for IRTracc-style linearization).
  - `MVAt0MM` (`double`) — Millivolts at zero millimeters (offset for diagnostics/average zeroing).
  - `Slope`, `Intercept` (`double`) — Linear coefficients (used for `IRTraccManual`).
  - `CalibrationFactor`, `ZeroPositionIntercept` (`double`) — Used for `IRTraccCalFactor`.
  - `UsemVOverVForPolys` (`bool`) — If `true`, polynomial inputs are converted to mV/V; defaults to `true`.
- **Constructors**:
  - `LinearizationFormula()` — Initializes with default coefficients `[0,0,0,0]` and exponents `[0,1,2,3]`.
  - `LinearizationFormula(LinearizationFormula copy)` — Copy constructor.
- **Methods**:
  - `bool IsValid()` / `void MarkValid(bool)` — Tracks validity state.
  - `string ToSerializeString()` — Serializes to `"{Style}_{params}"` format (e.g., `"Polynomial_c0xe0,c1xe1,...,S=...,mV=..."`).
  - `void FromSerializeString(string s)` — Parses serialized string; throws `NotSupportedException` on invalid format.
  - `string ToPolynomialString()` / `void FromPolynomialString(...)` — Handles polynomial-specific serialization.

## 3. Invariants

- **`BridgeType`**: Values are powers of two (bit flags); valid combinations are bitwise ORs of distinct values.
- **`ExcitationVoltageOption`**: Values are powers of two (bit flags); `GetExcitationVoltageMagnitudeFromEnum` and `GetExcitationVoltageEnumFromMagnitude` enforce bijection between enum and magnitude via `VoltageMagnitudeAttribute`.
- **`ZeroMethodType`**: Enum values are fixed for backward compatibility; `UsePreEventDiagnosticsZero` (value `1`) corresponds to `UsePreCalZero` in `OriginalZeroMethodType`.
- **`DigitalInputScaleMultiplier.Form`**: Only `ArbitraryLowAndHigh` is implemented; other forms would throw `NotSupportedException`.
- **`InitialOffset.Form`**: 
  - `EU`: `EU` is the direct offset in engineering units.
  - `EUAtMV`: `EU` is the engineering unit value observed at `MV`; actual offset in EU must be computed (not stored).
  - `None`: `EU` and `MV` are ignored.
- **`LinearizationFormula.Style`**: Each style has a required set of fields; e.g., `Polynomial` requires `_coefficients` and `_exponents`, while `IRTraccManual` requires `Slope` and `Intercept`.

## 4. Dependencies

### Imports/Usings
- `System.ComponentModel` — For `[Description]` attributes on enums.
- `System` — Core types (`Exception`, `Attribute`, `AttributeUsage`, `List`, `StringBuilder`, etc.).

### Inferred Usage
- **Consumers**: Likely used by database import/export logic (e.g., `DatabaseExport` namespace implies integration with legacy DB layers), sensor configuration UIs, and calibration tools.
- **Depends on**: 
  - `AttributeCoder<TEnum, TAttr, TValue>` (not shown in source) — Used by `VoltageMagnitudeAttributeCoder`.
  - `System.Globalization.CultureInfo` — For culture-invariant serialization/deserialization.
- **Depended on by**: 
  - Sensor configuration classes (e.g., `Test.Module.Channel.Sensor`).
  - Data processing pipelines that apply linearization or zero corrections.

## 5. Gotchas

- **`DigitalInputScaleMultiplier.FromDbSerializeString` is unimplemented**: The method body is commented out; calling it will silently return if `s == null` but otherwise throw `NotImplementedException` (or similar) at runtime.
- **`InitialOffset` copy constructor ignores null**: `InitialOffset(InitialOffset copy)` returns without error if `copy == null`, leaving the new instance in default state.
- **`ZeroMethodType` vs `OriginalZeroMethodType`**: The two enums have overlapping semantics but different names for `UsePreCalZero`/`UsePreEventDiagnosticsZero`; migration code must map them explicitly.
- **`ExcitationVoltageOption` values are powers of two, not sequential**: `Volt1 = 64`, `Volt2 = 2`, etc. — Do not assume ordering.
- **`LinearizationFormula` serialization is style-specific**: Each `Style` has a unique serialization format (e.g., polynomial uses comma-separated `cxe` pairs with `S=` and `mV=` suffixes); deserialization fails on unrecognized styles or malformed tokens.
- **Polynomial serialization assumes mV/V by default**: `UsemVOverVForPolys = true` converts input to mV/V before applying coefficients; GM-style inputs may require `false`.
- **`SensUnits.mVperVperEU` (value `3`)**: Rarely used; ensure downstream logic handles this case if present in legacy data.