---
source_files:
  - DataPRO/TDASCommands/TestTriggerCommands.cs
  - DataPRO/TDASCommands/CommandBase.cs
  - DataPRO/TDASCommands/TDASCommandPacketBase.cs
generated_at: "2026-04-16T03:47:17.202169+00:00"
model: "Qwen/Qwen3-Coder-Next-FP8"
schema_version: 1
sha256: "095345d9b2c6bf7d"
---

# TDASCommands

**Documentation: TDAS Test Trigger Commands Module**

---

### 1. Purpose

This module implements command classes for interacting with TDAS hardware modules to perform test trigger operations—specifically, arming, querying status, and disabling the trigger. It provides two public command types: `TestTrigger` (single-module, unicast) and `TestTriggerBroadcast` (single-module broadcast, unicast to a specific module index). These commands construct and send ASCII-based protocol commands (`TESTTRIG` or `*<N>TESTTRIG`) to TDAS devices and parse the ASCII response to extract the trigger status (`ARMED` or `OFF`). The module relies on the shared `CommandBase` and `TDASCommandPacketBase` infrastructure for communication, sequencing, and response handling.

---

### 2. Public Interface

#### `TestTrigger` class  
*Public, concrete command class for single-module test trigger operations.*

- **`int ModuleIndex`**  
  Gets or sets the module index (0–9). Setting it enforces `<10` and disables `RackCommand`.

- **`SubCommandValues SubCommand`**  
  Gets/sets the subcommand to send: `ARM`, `STATUS`, or `OFF`.  
  - *Getter* parses `_CommandString.SubCommand` as `SubCommandValues`.  
  - *Setter* writes the enum value as a string into `_CommandString.SubCommand`.

- **`StatusValues TriggerStatus`**  
  Gets the parsed trigger status from the last response: `ARMED` or `OFF`.  
  - *Getter* parses `_CommandString.Status` as `StatusValues`.  
  - Value is populated during `ProcessData()`.

- **`TestTrigger(ICommunication sock)`**  
  Constructor with default 30s timeout. Initializes `TDASCommandPacketBase` with `TestTriggerCommandString`, sets `RebuildBytes = true`, `RackCommand = false`, and default `SubCommand = STATUS`.

- **`TestTrigger(ICommunication sock, int msTimeout)`**  
  Constructor with configurable timeout. Same initialization as above, but uses provided timeout.

#### `TestTriggerBroadcast` class  
*Public, concrete command class for broadcast test trigger to a specific module.*

- **`SubCommandValues SubCommand`**  
  Same semantics as `TestTrigger.SubCommand`, operating on `_CommandString.SubCommand` of the underlying `TestTriggerBroadcastCommandString`.

- **`TestTriggerBroadcast(ICommunication sock, int moduleIndex)`**  
  Constructor with default timeout. Initializes `TDASCommandPacketBase` with `TestTriggerBroadcastCommandString(moduleIndex)`, sets `RackCommand = false`, `RebuildBytes = true`, and default `SubCommand = STATUS`.

- **`TestTriggerBroadcast(ICommunication sock, int moduleIndex, int msTimeout)`**  
  Constructor with configurable timeout. Same initialization as above.

#### Internal helper classes (not part of public API, but referenced for completeness)

- **`TestTriggerCommandString`**  
  *Internal* subclass of `CommandString`.  
  - `_CommandString => "TESTTRIG"`  
  - `_CommandDescription => "Test trigger"`  
  - `SubCommand` and `Status` properties (string) store subcommand and response status.  
  - `GetParameters()` returns `" <SubCommand>"` as ASCII bytes.

- **`TestTriggerBroadcastCommandString`**  
  *Internal* subclass of `CommandString`.  
  - `_CommandString => "*<N>TESTTRIG"` (if `ModuleIndex >= 0`) or `"*TESTTRIG"` otherwise.  
  - `_CommandDescription` mirrors `_CommandString`.  
  - `ModuleIndex`, `SubCommand` properties.  
  - Constructor accepts `moduleIndex`.  
  - `GetParameters()` same as `TestTriggerCommandString`.

---

### 3. Invariants

- **ModuleIndex constraint**:  
  `ModuleIndex` must be `<10` (enforced in `TDASCommandPacketBase.ModuleIndex` setter). Setting it to `>=10` throws an exception.

- **RackCommand mutual exclusion**:  
  Setting `ModuleIndex` in `TDASCommandPacketBase` sets `RackCommand = false`. `RackCommand` is only `true` when `ModuleIndex` is unset (default `' '` space) and not explicitly set to a digit.

- **Default subcommand**:  
  All constructors initialize `_CommandString.SubCommand = "STATUS"`.

- **Response parsing invariant**:  
  `ProcessData()` in `TestTrigger` parses the response into tokens; status is assigned from `tokens[1]` if `tokens.Length >= 2`. If parsing fails, `_CommandString.Status` remains unchanged.

- **Response format assumption**:  
  TDAS responses are ASCII, newline-terminated (`\r\n`), and contain the command string followed by a space and status (e.g., `TESTTRIG ARMED\r\n`). Parsing assumes this format.

- **`RebuildBytes = true`**:  
  All `TestTrigger*` constructors set `RebuildBytes = true`, ensuring `CommandString.GetBytes()` regenerates the byte array on each `ToBytes()` call (critical for dynamic `SubCommand` changes).

---

### 4. Dependencies

#### Imports / References (from source):
- `DTS.Common.ICommunication` → `ICommunication` interface for socket communication.
- `DTS.DASLib.Command.TDAS` namespace:
  - `CommandBase` (base class for all commands, provides `ProcessData`, `ResponseData`, `SyncExecute`, throttling).
  - `TDASCommandPacketBase` (packet construction, verification, MDB mode support).
  - `CommandString` (abstract base for command strings).
- `System.Text.Encoding` (ASCII encoding/decoding).
- `System.Threading` (used in `CommandBase` for `SemaphoreSlim` throttling).

#### Inferred callers:
- Likely instantiated by higher-level test or configuration logic (e.g., test harnesses, calibration tools).
- Uses `CommandBase` infrastructure, so depends on:
  - `APILogger` (for logging errors and command/response).
  - Throttling via `CommandBase.InitializeSemaphore()` (default: 3 concurrent operations, 100ms delay).

#### Dependencies on other modules:
- `TDASCommandPacketBase` → depends on `MDB_BLOCK` (for data mode parsing), `CommandPacketBase` (base), and `CommandString`.
- `CommandBase` → depends on logging infrastructure (`TextLogger`, `APILogger`), threading (`SemaphoreSlim`), and `AbstractCommandBase`.

---

### 5. Gotchas

- **`ModuleIndex` parsing is fragile**:  
  `ModuleIndex` getter in `TDASCommandPacketBase` uses `int.Parse(new string(_moduleIndex, 1))`. If `_moduleIndex` is `' '` (space), this throws `FormatException`. This is avoided in `TestTrigger` constructors because `ModuleIndex` is never explicitly set, but if used directly, it may fail.

- **`TriggerStatus` may be stale or empty**:  
  `TriggerStatus` reads `_CommandString.Status`, which is only updated in `ProcessData()`. If `ResponseData` is accessed before `ProcessData()` runs (e.g., via `ResponseData` getter), `ProcessData()` executes—but if the response is malformed or missing, `_CommandString.Status` may remain `null` or unchanged, causing `Enum.Parse` to throw.

- **`ProcessData()` in `TestTrigger` is custom and narrow**:  
  Unlike `CommandBase.ProcessData()`, `TestTrigger.ProcessData()` manually parses the response using `GetCommandPortion()` and `ResponseData.Split`. It assumes the response contains the command string followed by a space and status. Deviations (e.g., extra whitespace, different order) may cause parsing failure.

- **No validation of `SubCommand` enum values in setter**:  
  `SubCommand` setter directly assigns `value.ToString()` to `_CommandString.SubCommand`. If an invalid enum value is passed (e.g., via reflection or cast), no validation occurs—though `Enum.Parse` in getter may throw.

- **`TestTriggerBroadcastCommandString.ModuleIndex` is not validated**:  
  The broadcast command accepts any `moduleIndex`, but the command string uses `*<N>TESTTRIG`. If `moduleIndex < 0`, it falls back to `*TESTTRIG` (broadcast to all modules). This may be unintended.

- **Throttling is global and static**:  
  `CommandBase` uses static `_pool` and `_semaphoreDelay`. If `InitializeSemaphore()` is not called, defaults (`spots=3`, `delay=100ms`) apply. This affects all `TestTrigger`/`TestTriggerBroadcast` instances.

- **`RebuildBytes` must be `true` for dynamic updates**:  
  If `RebuildBytes` is accidentally set to `false`, changing `SubCommand` will not affect the outgoing command bytes until `RebuildBytes = true` or `cs.RebuildBytes()` is called.

- **No error handling in `ProcessData()` for malformed responses**:  
  If `ResponseData` does not contain the expected format (e.g., missing `\r\n`, insufficient tokens), `ProcessData()` silently returns without updating `_CommandString.Status`. This may lead to stale status values.

- **`GetParameters()` returns a leading space**:  
  Both `TestTriggerCommandString` and `TestTriggerBroadcastCommandString` return `" <SubCommand>"` (note leading space). This matches TDAS protocol expectations but is non-obvious.

- **`ModuleIndex` setter in `TDASCommandPacketBase` throws on `>=10`**:  
  This is a hard constraint. If future hardware supports >10 modules, this will break.

- **`ExpectsData = true` by default in `CommandString`**:  
  `TestTrigger`/`TestTriggerBroadcast` do not override this, so `ExpectsData = true`. If the TDAS response for `TESTTRIG` is status-only (no data), `VerifyPacket()` may behave unexpectedly (see `TDASCommandPacketBase.VerifyPacket()` logic).

- **`ToCommandString()` strips control characters**:  
  `ToCommandString()` removes `\r\n` and `\0`, which may obscure debugging if raw bytes are needed.

- **`CommandBase.ProcessData()` may throw**:  
  If `ResponseData` contains `"ERR"`, `ProcessData()` throws `InvalidOperationException`. This is caught only if the caller handles it.

- **`TestTriggerBroadcast` does not expose `ModuleIndex`**:  
  The `moduleIndex` is stored in the internal `TestTriggerBroadcastCommandString`, but not exposed as a property. Callers must track it externally.

--- 

*End of documentation.*