---
source_files:
  - Common/DTS.Common.Storage/Classes/NoDBAccessException.cs
  - Common/DTS.Common.Storage/Classes/DigitalInputSettings.cs
  - Common/DTS.Common.Storage/Classes/DbTypeAttr.cs
  - Common/DTS.Common.Storage/Classes/DAS.cs
  - Common/DTS.Common.Storage/Classes/MMETables.cs
generated_at: "2026-04-16T02:10:51.158458+00:00"
model: "Qwen/Qwen3-Coder-Next-FP8"
schema_version: 1
sha256: "ad177a41b5582582"
---

# Classes

## Documentation: `DTS.Storage` Common Storage Types

---

### 1. Purpose

This module defines core data model types and metadata used for interacting with a proprietary database in the DTS (Data Acquisition and Test System) ecosystem. It provides strongly-typed constants for table and column names, custom exception types for access control, and reflection-based utilities for mapping .NET enum values to database-specific type strings. Its role is to decouple database schema knowledge from business logic, enabling type-safe, maintainable data access across the system.

---

### 2. Public Interface

#### `NoDBAccessException`
- **Signature**: `public class NoDBAccessException : Exception`
- **Behavior**: A custom exception class wrapping another exception (`ex`) to indicate a database access denial or failure. It preserves the original exception’s message and inner exception.

#### `DigitalInputSettings`
- **Fields**:
  - `public const string Table = "tblDigitalInputSetting";`
  - `public enum Fields { ... }`  
    Enumerates column names for the `tblDigitalInputSetting` table:  
    `SettingName`, `SettingMode`, `ScaleMultiplier`, `LastModified`, `LastModifiedBy`, `SensorId`, `UserValue1`, `UserValue2`, `UserValue3`, `UserTags`.

#### `DbTypeAttr`
- **Fields**:
  - `public string DbType { get; }` – Stores the database type string.
- **Methods**:
  - `public static string GetDbType(object o)` – Uses reflection to retrieve the `DbType` string associated with an enum *value* (via its `MemberInfo`). Returns `null` if no attribute is found.

#### `DAS`
- **Fields**:
  - `public const string Table = "tblDAS";`
  - `public enum Fields { ... }`  
    Enumerates columns for `tblDAS`:  
    `SerialNumber`, `Type`, `MaxModules`, `MaxMemory`, `MaxSampleRate`, `MinSampleRate`, `FirmwareVersion`, `CalDate`, `ProtocolVersion`, `LastModified`, `LastModifiedBy`, `Version`, `LocalOnly`, `LastUsed`, `LastUsedBy`, `Connection`, `Channels`, `Position`, `ChannelTypes`, `Reprogramable`, `Reconfigurable`, `IsModule`.
  - `public const string TableDASChannels = "tblDASChannels";`
  - `public enum DASChannelFields { ... }`  
    Enumerates columns for `tblDASChannels`:  
    `HardwareId`, `ChannelIdx`, `SupportedBridges`, `SupportedExcitations`, `DASDisplayOrder`, `LocalOnly`, `SupportedDigitalInputModes`, `SupportedSquibFireModes`, `SupportedDigitalOutputModes`, `ModuleSerialNumber`, `ModuleArrayIndex`.
  - **Prototype Constants**:  
    A large set of `public const string` values representing known DAS hardware prototypes (e.g., `"SLICE1 Prototype"`, `"G5 VDS Prototype"`, `"SLICE PRO Lab TOM"`). Used for identifying device types.

#### `MMETables`
- **Fields**:
  - `public const string MyType = "MyType";`  
    Legacy table name (used up to version 1.3.496), superseded by `CustomChannelType`.
  - `public const string CustomChannelType = "CustomChannelType";`  
    Intermediate table name (versions 1.3.498–1.3.515), superseded by `"TYPE"`.
  - `public const string Id = "Id";`  
    Legacy column name (up to 1.3.515), superseded by `"ID"`.
  - **Table Names & Field Enums**:
    - `MMEPossibleChannelsTable = "tblMMEPossibleChannels"`  
      `MMEPossibleChannelsFields` enum with fields like `ID`, `TYPE`, `TEST_OBJECT`, `POSITION`, `PHYSICAL_DIMENSION`, `DIRECTION`, `DEFAULT_FILTER_CLASS`, `TEXT_L1`, `TEXT_L2`, `VERSION`, `DATE`, `REMARKS`, `EXPIRED`, `SORTKEY`, `PICTURE_SHORTNAME`, `LAST_CHANGE`, `LAST_CHANGE_TEXT`, `HISTORY`.  
      Several fields are annotated with `[CustomChannelFieldSize(n)]` (not defined in this file—likely elsewhere).
    - `MMEDirectionsTable = "tblMMEDirections"`  
      `MMEDirectionsFields` enum: `s_GUID`, `DIRECTION`, `TEXT_L1`, `TEXT_L2`, `DATE`, `VERSION`, `EXPIRED`, `REMARKS`, `LAST_CHANGE`, `LAST_CHANGE_TEXT`, `HISTORY`, `SORTKEY`.
    - `MMEFilterClassesTable = "tblMMEFilterClasses"`  
      `MMEFilterClassesFields` enum: `s_GUID`, `FILTER_CLASS`, `TEXT_L1`, `TEXT_L2`, `VERSION`, `DATE`, `REMARKS`, `EXPIRED`, `SORTKEY`, `LAST_CHANGE`, `LAST_CHANGE_TEXT`, `HISTORY`.
    - `MMEFineLocations1Table`, `MMEFineLocations2Table`, `MMEFineLocations3Table`  
      Corresponding enums with `s_GUID`, location field (`FINE_LOC_1`/`2`/`3`), `TEXT_L1`, `TEXT_L2`, `VERSION`, `DATE`, `REMARKS`, `EXPIRED`, `SORTKEY`, `LAST_CHANGE`, `LAST_CHANGE_TEXT`, `HISTORY`.
    - `MMEPhysicalDimensions = "tblMMEPhysicalDimensions"`  
      `MMEPhysicalDimensionFields` enum includes `s_GUID`, `PHYSICAL_DIMENSION`, `TEXT_L1`, `TEXT_L2`, `DEFAULT_UNIT`, dimensional exponents (`LENGTH_EXP`, `TIME_EXP`, etc.), `VERSION`, `DATE`, `REMARKS`, `EXPIRED`, `SORTKEY`, `LAST_CHANGE`, `LAST_CHANGE_TEXT`, `HISTORY`.
    - `MMEPositionsTable = "tblMMEPositions"`  
      `MMEPositionsFields` enum: `s_GUID`, `POSITION`, `TEXT_L1`, `TEXT_L2`, `VERSION`, `DATE`, `REMARKS`, `EXPIRED`, `SORTKEY`, `LAST_CHANGE`, `LAST_CHANGE_TEXT`, `HISTORY`.
    - `MMETestObjectsTable = "tblMMETestObjects"`  
      `MMETestObjectsFields` enum: `s_GUID`, `TEST_OBJECT`, `TEXT_L1`, `TEXT_L2`, `VERSION`, `DATE`, `REMARKS`, `EXPIRED`, `SORTKEY`, `LAST_CHANGE`, `LAST_CHANGE_TEXT`, `HISTORY`.
    - `MMEMainLocationTable = "tblMMEMainLocations"`  
      `MMEMainLocationsFields` enum: `s_GUID`, `TYPE`, `TRANS_MAIN_LOC`, `TEXT_L1`, `TEXT_L2`, `VERSION`, `DATE`, `REMARKS`, `EXPIRED`, `SORTKEY`, `PICTURE_SHORTNAME`, `LAST_CHANGE`, `LAST_CHANGE_TEXT`, `HISTORY`.

> **Note**: `[CustomChannelFieldSize(n)]` is referenced in `MMETables` but *not defined in the provided source files*. Its definition is unknown.

---

### 3. Invariants

- **`DbTypeAttr.GetDbType` behavior**:
  - Only inspects the *first* member info (`mi[0]`) returned by `GetType().GetMember(o.ToString())`.
  - Returns `null` if the object is `null`, no member is found, or no `DbTypeAttr` is applied to the enum value.
  - Assumes the enum value’s name matches a member name on its type (standard for `enum.ToString()`).
- **Table/column naming**:
  - Table names are hardcoded string constants (e.g., `"tblDAS"`, `"tblMMEPossibleChannels"`).
  - Field names in enums map directly to database column names (e.g., `DAS.Fields.SerialNumber` → `"SerialNumber"`).
- **Versioning semantics**:
  - `MyType`, `CustomChannelType`, and `Id` are explicitly marked as legacy. Their usage is version-gated in the system (not enforced in this module).
- **Prototype constants**:
  - All prototype names are exact string literals; no normalization or canonicalization is performed in this module.

---

### 4. Dependencies

- **Dependencies *of* this module**:
  - `System` (for `Exception`, `Attribute`, `MemberInfo`, `Reflection`).
  - No external libraries beyond .NET Framework base types.
- **Dependencies *on* this module**:
  - Any module performing database access using these schema constants (e.g., data access layers, configuration tools, migration scripts).
  - Code that uses `DbTypeAttr` for dynamic SQL generation or type mapping.
  - Modules handling DAS device metadata (e.g., device discovery, configuration, calibration).
  - Modules managing MME (likely "Measurement Model Exchange") metadata (e.g., channel definition, test setup, reporting).

---

### 5. Gotchas

- **`[CustomChannelFieldSize]` is undefined here**:  
  The `MMETables` enum uses `[CustomChannelFieldSize(n)]` attributes, but this attribute type is *not defined* in the provided source. Its behavior and usage are unknown.
- **`DbTypeAttr.GetDbType` is fragile**:  
  Relies on `GetMember(o.ToString())`, which may fail or return unexpected results if enum values have custom names or if reflection is blocked (e.g., in some AOT or security contexts).
- **Legacy table/column names are *not* handled programmatically**:  
  `MyType`, `CustomChannelType`, and `Id` are documented as historical, but no runtime logic is present to select the correct name based on version. Consumers must manage version compatibility themselves.
- **Prototype strings are magic**:  
  All `PROTOTYPE` constants are raw strings. No validation or enum-based safety prevents typos or mismatches in device type identification.
- **No validation in `NoDBAccessException`**:  
  The constructor accepts any `Exception`, including `null` (though `ex.Message` would throw if `ex` is `null`). This may lead to `NullReferenceException` at construction time if misused.
- **Case sensitivity**:  
  Enum field names (e.g., `ID` vs `Id`) are used verbatim. Ensure database column names match *exactly* (case-sensitive in some DBMSs).