---
source_files:
  - DataPRO/TDASCommands/TestTriggerCommands.cs
  - DataPRO/TDASCommands/CommandBase.cs
  - DataPRO/TDASCommands/TDASCommandPacketBase.cs
generated_at: "2026-04-17T15:49:45.052194+00:00"
model: "zai-org/GLM-5-FP8"
schema_version: 1
sha256: "b0635eb6f7e0c765"
---

# TDAS Command Module Documentation

## 1. Purpose

This module provides the command infrastructure for communicating with TDAS (Test Data Acquisition System) hardware. It implements a command/response protocol for sending control commands (such as test triggers) and receiving data, handling packet construction, response parsing, communication throttling, and diagnostic logging. The module supports both single-module and broadcast command modes for controlling test trigger states (ARM, STATUS, OFF) across TDAS recording devices.

---

## 2. Public Interface

### `TestTrigger` (class)
Executes test trigger commands against a specific TDAS module.

**Constructors:**
- `TestTrigger(DTS.Common.Interface.DASFactory.ICommunication sock)` — Creates command with default 30000ms timeout.
- `TestTrigger(DTS.Common.Interface.DASFactory.ICommunication sock, int msTimeout)` — Creates command with custom timeout.

**Properties:**
- `int ModuleIndex` — Gets or sets the target module index.
- `SubCommandValues SubCommand` — Gets or sets the subcommand (`ARM`, `STATUS`, `OFF`).
- `StatusValues TriggerStatus` — Gets the trigger status from the response (`ARMED`, `OFF`).

**Nested Enums:**
- `SubCommandValues { ARM, STATUS, OFF }`
- `StatusValues { ARMED, OFF }`

---

### `TestTriggerBroadcast` (class)
Executes broadcast test trigger commands to TDAS modules.

**Constructors:**
- `TestTriggerBroadcast(DTS.Common.Interface.DASFactory.ICommunication sock, int moduleIndex)`
- `TestTriggerBroadcast(DTS.Common.Interface.DASFactory.ICommunication sock, int moduleIndex, int msTimeout)`

**Properties:**
- `TestTrigger.SubCommandValues SubCommand` — Gets or sets the subcommand.

---

### `CommandBase` (class)
Base class for TDAS commands providing execution, response handling, and logging.

**Constructors:**
- `CommandBase(DTS.Common.Interface.DASFactory.ICommunication sock)`
- `CommandBase(DTS.Common.Interface.DASFactory.ICommunication sock, int timeoutMillisec)`

**Properties:**
- `string ResponseData` — Lazy-loaded response data; calls `ProcessData()` on first access.
- `bool SingleModuleCommand` — Gets or sets whether this is a single-module command.
- `string RackSerialNumber` — Gets or sets the rack serial number (default: `"NONE"`).

**Methods:**
- `bool IsErrored()` — Returns `true` if response starts with `"err"` (case-insensitive).
- `string GetErrorString()` — Extracts error message from response starting at `"ERR"` + 4 characters.
- `void SyncExecute()` — Executes command with semaphore-based throttling.
- `static void InitializeSemaphore(double delay, int spots)` — Initializes throttling parameters.
- `static void RollLog()` — Triggers log file rollover.

---

### `TDASCommandPacketBase` (class)
Builds and parses TDAS command packets.

**Constructors:**
- `TDASCommandPacketBase(CommandString cs)` — Creates packet from a command string.
- `TDASCommandPacketBase(byte[] buffer, CommandPacketBase command)` — Creates packet from response bytes.

**Properties:**
- `bool RackCommand` — Gets or sets whether this is a rack-level command.
- `bool SingleModuleCommand`
- `string RackSerialNumber`
- `int ModuleIndex` — Must be < 10; throws `Exception` otherwise. Setting this sets `RackCommand = false`.
- `bool AllModule`
- `bool RebuildBytes` — When `true`, forces byte rebuild on serialization.
- `bool ExpectsData`
- `bool ExpectsMultipleLines`
- `int LinesExpected`
- `bool UseMDBMode` — Enables MDB (Memory Data Block) parsing mode.
- `bool MonitorDataMode`
- `bool RealtimeCommand`
- `byte CharWait` — Character wait value (default: `0x01`).
- `int ReplyWait` — Reply wait value (default: `30`).

**Methods:**
- `byte[] ToBytes()` — Serializes packet to 536-byte CDB format.
- `string GetCommandString(int index)` — Gets command string at index.
- `CommandString GetCommandStringObject(int index)` — Gets `CommandString` object at index.
- `string ToCommandString()` — Returns ASCII command string from bytes.
- `int GetExpectedBytes()` — Returns expected data bytes in MDB mode.
- `short[] GetData()` — Extracts data from MDB blocks.
- `PacketState VerifyPacket(byte[] Bytes)` — Validates response packet completeness.
- `void GetNextSequenceNumber()` — Assigns next global sequence number (thread-safe).
- `void ComputeCRCs()` — No-op in this implementation.

---

### `CommandString` (abstract class)
Base class for defining command strings.

**Properties:**
- `virtual string RequiredResponseString` — Required response marker for packet completion validation.
- `bool ExpectsData` — Default: `true`.
- `bool ExpectsMultipleLines`
- `int LinesExpected`
- `bool RackCommand` — Default: `true`.
- `bool SingleModuleCommand`
- `string RackSerialNumber`
- `int Length` — Cached byte length of command.

**Methods:**
- `virtual byte[] GetParameters()` — Override to provide command parameters; default returns empty array.
- `string GetCommandPortion()` — Returns the command string.
- `string GetCommandDescription()` — Returns command description.
- `byte[] GetBytes()` — Serializes command with parameters and CRLF terminator.
- `void RebuildBytes()` — Clears cached bytes to force rebuild.

---

### `CommandPacketException` (class)
Exception for command packet errors.

**Constructor:**
- `CommandPacketException(ERROR_CODES errorCode, string description)`

**Properties:**
- `ERROR_CODES ErrorCode` — Returns `UNKNOWN` if not set.

**Enum:**
- `ERROR_CODES { TOO_MANY_COMMANDS = 0, TOO_MANY_BYTES = 1, UNKNOWN = 2 }`

---

## 3. Invariants

1. **Module Index Constraint:** `ModuleIndex` must be less than 10; otherwise `TDASCommandPacketBase` throws an `Exception`.
2. **Command Limits:** Maximum of 1 command per packet (`MAX_CMD = 1`) and maximum 512 bytes per command (`MAX_CMD_SIZE = 512`).
3. **Packet Size:** CDB packet size is fixed at 536 bytes (`CDB_SIZE = 536`).
4. **MDB Block Sizes:** `MDB_BLOCK_SIZE = 52`, `DMA_SIZE = 1024`, `DMA_BLOCK_SIZE = 1076`.
5. **Default Timeout:** Commands default to 30000ms timeout.
6. **Default Throttling:** Semaphore defaults to 3 concurrent spots with 100ms delay.
7. **Status Packet Structure:** TDAS status packet is 20 bytes, ending with 4 bytes of `0xFF` at positions 16-19.
8. **Sequence Numbers:**