DP44/enriched-partialglm/Common/DTS.Common.Serialization/DDAS (Chrysler)/FromChrysler.md

---
source_files:
  - Common/DTS.Common.Serialization/DDAS (Chrysler)/FromChrysler/ChannelDefinition.h
  - Common/DTS.Common.Serialization/DDAS (Chrysler)/FromChrysler/FilePath.h
  - Common/DTS.Common.Serialization/DDAS (Chrysler)/FromChrysler/DDASTestDefinition.h
  - Common/DTS.Common.Serialization/DDAS (Chrysler)/FromChrysler/DataFloat.h
generated_at: "2026-04-16T10:56:49.501225+00:00"
model: "zai-org/GLM-5-FP8"
schema_version: 1
sha256: "289fd9f58c0583bc"
---

# DDAS (Chrysler) Serialization Module Documentation

## 1. Purpose

This module provides data structures and utility classes for serializing and deserializing DDAS (Dynamic Data Acquisition System) test configuration and floating-point data files used in Chrysler/DaimlerChrysler automotive testing. It defines the binary file formats for test definitions (`.tdf` files), floating-point data files (`.fpd` files), and supporting structures for channel configuration, transducer definitions, and file path manipulation. The module serves as the bridge between legacy DDAS hardware configurations and the software systems that process crash test and sensor data.

---

## 2. Public Interface

### ChannelDefinition.h

#### Enumerations
- **`ChannelFlags`** — Contains `CHANFLAG_ACTIVE` for channel active state flagging.

#### Macros
- **`ISCHANACTIVE(pChan)`** — Returns 1 if channel active flag is set, 0 otherwise.
- **`SETCHANACTIVE(pChan)`** — Sets the channel active flag.
- **`CLRCHANACTIVE(pChan)`** — Clears the channel active flag.

#### Structures
- **`CHANNEL`** (typedef `tagCHANNEL`) — 128+ byte structure containing:
  - `short Size` — Size of this object
  - `short Flags` — Channel flags
  - `char Name[64]` — Channel name
  - `char Sign[8]` — Sign (+, -, or blank)
  - `char Axis[8]` — Axis identifier (X, Y, Z, FX, MX, AX, etc.)
  - `float FilterFreq` — Filter frequency in Hz
  - `float SetGain` — Gain setting (1 - n)
  - `float ActGain` — Actual/measured gain setting
  - `float Rcal` — Shunt calibration resistance
  - `float Excitation` — Excitation voltage (when programmable)
  - `byte byteSpares[4]` — Spare bytes (formerly `CalDate`)
  - `TRANSDUCER Transducer` — Snapshot of transducer values

#### Type Aliases
- **`PCHANNEL`** — Pointer to `CHANNEL`
- **`PCHAN`** — Alias for `PCHANNEL`

---

### FilePath.h

#### Constants
- **`PATHLENMAX`** — Maximum path length allowed (300 characters)

#### Enumerations
- **`FileSpecOK`** — Bitmask flags for file specification validation:
  - `FSPEC_EXTOK = 0x1` — File extension valid
  - `FSPEC_NAMEOK = 0x2` — File name valid
  - `FSPEC_PATHOK = 0x4` — File path valid
  - `FSPEC_ROOTOK = 0x8` — Drive or computer valid
  - `FSPEC_RELATIVEPATH = 0x10` — Path is relative

#### Class `CFilePath`
Public methods:
- **`CFilePath()`** — Default constructor
- **`virtual ~CFilePath()`** — Destructor
- **`void operator=(const CFilePath &src)`** — Assignment operator
- **`int SetFullFilePathAndName(char* szPathAndName)`** — Set complete file path
- **`int SetDriveOrResource(char *szNewDrive, int* nNext)`** — Set drive or network resource
- **`int SetDrive(int nDriveAis1)`** — Set drive number (A=1)
- **`int SetDir(char *szNewDir, int* nNext)`** — Set directory path
- **`int SetFile(char *szNewFile, int *nNext)`** — Set file name
- **`int SetExtension(char *szNewExt)`** — Set file extension
- **`int ParseFilePathAndName(char *szPathAndName)`** — Parse full path into components
- **`const char* GetFullFilePathAndName()`** — Retrieve complete path
- **`const char* GetFileName()`** — Retrieve file name
- **`const CString GetFileNameExt()`** — Retrieve file name with extension
- **`const char* GetFileExtension()`** — Retrieve extension
- **`BOOL FileExists()`** — Check if file exists
- **`bool IsPathComplete(int *pFlgValid)`** — Check if path is complete
- **`bool IsFileType(char *szFileTypeExt)`** — Check file type by extension
- **`bool IsFileValid(const char* szFileSpec, const char *szFileTypeExt, CString* pcsError)`** — Validate file specification
- **`bool IsAllValidChars(char* szInString, int* pnPosBad)`** — Validate characters in string
- **`void Clear()`** — Reset all path components

---

### DDASTestDefinition.h

#### Constants
- **`TESTDEFEXT`** — Test definition file extension (".tdf")
- **`DDASTYPENAME`** — "DDAS V5"
- **`DDASFILEVERS`** — "Ver 500"
- **`MAXTRIGCHANS`** — Maximum trigger channels (4)
- **`TRIGCHANDSBL`** — Trigger channel disable flag (0x80)

#### Enumerations
- **`FileTypeFlags`** — `FILETYPE_IMPORTED4X` for tests imported from 4.x format
- **`HardwareType`** — Hardware identifiers: `HWTYPE_UNKNOWN`, `HWTYPE_DDAS3`, `HWTYPE_KAYSERTHREDE`, `HWTYPE_COUNT`
- **`AnalogOptionFlags`** — `ANAOPT_CHANTRIGGERS` for analog unit channel triggers
- **`MemoryOptionFlags`** — `MEMOPT_TAPEMODE`, `MEMOPT_PREEVENT`, `MEMOPT_PREEVENTXXX`
- **`RecordModes`** — `RECORDMODE_EVENT`, `RECORDMODE_TAPE`

#### Structures
- **`FILEINFOBLOCK`** — File metadata (size, type name, version, flags, creator/updater names)
- **`DATASYSTEMBLOCK`** — System configuration (number of systems, channels per system, max sample rate, config block size)
- **`DDASCONFIGBLOCK`** — Per-system configuration (analog/memory unit numbers, options, memory size)
- **`ACQUISITIONBLOCK`** — Data acquisition parameters (record mode, sample rate, total samples, pre-event samples, tape mode channels, trigger block count)
- **`TRIGCHANDEF`** — Channel trigger definition (`ChanNo`, `LevelPct`)
- **`TRIGCHANBLOCK`** — Trigger channel block (size, count, array of `TRIGCHANDEF`)

---

### DataFloat.h

#### Constants
- **`TESTPATHSIZE`** — 128 (if not already defined)
- **`FILEERROR`** — -1
- **`FLOATDATANAME`** — "DDAS FlPt"
- **`FLOATDATARAW`** — "DDAS fpRAW"
- **`FLOATDATAVER`** — "Ver 500"
- **`RawExt`** — ".raw"
- **`FlPtExt`** — ".fpd"

#### Enumerations
- **`FileTypes`** — `UNKNOWN`, `FLOATPOINT`, `PROCESSED`
- **`PeakTypes`** — `PEAKS_MINMAX`, `PEAKS_3MSCONTIN`, `PEAKS_3MSCUMUL`
- **`FPDVerbosity`** — `FPD_SILENT`, `FPD_ERRORS`, `FPD_STATUS`, `FPD_RESULTS`, `FPD_VERBOSE`

#### Structures
- **`TESTINFO`** — Test metadata (device ID, channel number, sample rate, total samples, pre-event samples, channel number in system, calibration points, test creation path, time axis title, spare bytes)
- **`FILEHEADER`** — File header containing `FILEINFOBLOCK`, `TESTINFO`, `CHANNEL`, and 32 spare bytes
- **`DATAPEAK`** — Peak data (`Min`, `Xmin`, `Max`, `Xmax`)
- **`DATAHIST`** — Histogram data (`fVal`, `nOccurrences`)

#### Class `CDataFloat`
Public methods:
- **`CDataFloat()`** — Default constructor
- **`CDataFloat(unsigned int nSize)`** — Constructor with initial size
- **`virtual ~CDataFloat()`** — Destructor
- **`void operator=(const CDataFloat &src)`** — Assignment operator
- **`bool SetSize(long lNumberElements)`** — Resize data array
- **`long GetSize()`** — Get array size
- **`bool SetIndexToStart()`** — Reset buffer pointer to start
- **`bool StoreDataNext(float fData)`** — Store next data value
- **`bool GetDataNext(float* fData)`** — Retrieve next data value
- **`float* GetDataBuffer()`** — Get pointer to data buffer
- **`CArray<float, float&>* GetDataArray()`** — Get reference to data array
- **`int AppendArrayFloat(CArray<float, float&>* srcArray)`** — Append data from another array
- **`bool ReadFromFile(const char *lpFilename)`** — Read data from file
- **`bool WriteToFile(const char *lpFilename, bool bPrint)`** — Write data to file
- **`FILEHEADER* GetFileHeader()`** — Get file header structure
- **`FILEINFOBLOCK* GetFileInfo()`** — Get file info block
- **`TESTINFO* GetTestInfo()`** — Get test info structure
- **`CHANNEL* GetChannel()`** — Get channel definition
- **`int GetChannelNumber()`** — Get channel number
- **`int GetChannelNumberInBox()`** — Get channel number in box/system
- **`long GetSampleRate()`** — Get sample rate
- **`int GetEventOffset()`** — Get event offset
- **`float GetStartTime(bool bmSec)`** — Get start time (seconds or milliseconds)
- **`float GetStopTime(bool bmSec)`** — Get stop time
- **`float GetStartTimeData(bool bmSec)`** — Get data start time
- **`float GetStopTimeData(bool bmSec)`** — Get data stop time
- **`int ConvertTimeToIndex(float fTime)`** — Convert time to array index
- **`float ConvertIndexToTime(int nIndex)`** — Convert index to time
- **`int CalcSampIn3mSecInt()`** — Calculate samples in 3 milliseconds
- **`bool GetTimeAtValue(float fValue, float *pTvalue)`** — Find time at which a value occurs
- **`bool GetDataPeaks(...)`** — Multiple overloads for retrieving peak data
- **`void SetChannelName(char* szNewChannelName)`** — Set channel name
- **`void SetEngrgUnits(char *szNewEngrgUnits)`** — Set engineering units
- **`bool VerifyAndCoerceAxis(bool bNegativeSign, const char* szAxis, BOOL bVerbose)`** — Validate and correct axis designation
- **`int SetFilePathAndName(char* szNewFileSpec)`** — Set file path
- **`const char* GetFilePathAndName()`** — Get file path
- **`const char* GetFileTitle()`** — Get file title
- **`const char* GetFileExt()`** — Get file extension
- **`const CString GetFileName()`** — Get file name
- **`CString GetDataSetName(CString &csName)`** — Get data set name
- **`float GetFilterClass()`** — Get filter class
- **`int ClearAll(long NewNumberElements)`** — Clear and resize array

#### Inner Class `CDataFloat::CPeakList`
- **`void AddDataPoint(DATAHIST* pDHist)`** — Add data point to histogram
- **`void Get3msMin(int nPtPer3ms, DATAHIST* pDHist)`** — Get 3ms minimum
- **`void Get3msMax(int nPtPer3ms, DATAHIST* pDHist)`** — Get 3ms maximum
- **`void RemoveAll()`** — Clear all entries

---

## 3. Invariants

### Channel Definition
- `CHANNEL.Size` must reflect the actual size of the structure for versioning/serialization compatibility.
- `byteSpares[4]` in `CHANNEL` is fixed at 4 bytes; this was formerly `CalDate` (a `time_t`) and must not be repurposed without coordination with transducer date fields.

### File Path
- `PATHLENMAX` (300) is the maximum allowed path length.
- `CFilePath` maintains separate string pointers for root, directory, name, and extension components.

### Test Definition
- `FILEINFOBLOCK.FileTypeFlags` encodes hardware type in upper 16 bits and file type in lower 16 bits.
- `TRIGCHANDEF.ChanNo` and `LevelPct` must both be non-zero, and `TRIGCHANDSBL` must not be set in `LevelPct` for a trigger to be enabled.
- `TRIGCHANBLOCK.TrigChan` array is sized to `MAXTRIGCHANS` (4) but documented as variable-size in practice.
- `ACQUISITIONBLOCK.PreEventSamples` is only valid in `RECORDMODE_EVENT` mode.
- `ACQUISITIONBLOCK.TapeModeChannels` is only valid in `RECORDMODE_TAPE` mode.

### Data Float
- `FILEHEADER` has a fixed 32-byte spare section at the end.
- `TESTINFO` includes 2 spare bytes for 4-byte alignment.
- `FloatData` array and `pfBfr` pointer must remain synchronized; `SetIndexToStart()` resets `pfBfr` to the beginning of `FloatData`.

---

## 4. Dependencies

### This Module Depends On
- **`TransducerDefinition.h`** — Required by `ChannelDefinition.h` for `TRANSDUCER` type (not provided in source).
- **`<Afxtempl.h>`** — MFC template classes (`CArray`, `CList`) used in `DataFloat.h`.
- **MFC/ATL** — `CString` class used in `FilePath.h` and `DataFloat.h`.

### Consumers (Inferred)
- Any system reading or writing DDAS test definition files (`.tdf`).
- Any system reading or writing DDAS floating-point data files (`.fpd` or `.raw`).
- Crash test data analysis tools processing channel and transducer configurations.

---

## 5. Gotchas

### Historical Artifacts
1. **Removed `CalDate` field**: The `CHANNEL` structure formerly contained a `time_t CalDate` field. This was removed per revision on 11/08/04 and replaced with `byteSpares[4]`. The calibration date is now stored in the embedded `TRANSDUCER` structure. Code that assumes `CalDate` exists in `CHANNEL` will fail.

2. **Variable-size array pattern**: `TRIGCHANBLOCK.TrigChan` is declared with `MAXTRIGCHANS` elements but comments indicate it "will be a variable size array." This suggests the binary format may contain fewer than 4 entries in actual files, and `NumTrigs` should be used to determine actual count.

### Binary Format Considerations
3. **Alignment padding**: `TESTINFO` includes `SpareBytes[2]` explicitly for 4-byte alignment. Modifying this structure requires maintaining alignment for binary compatibility.

4. **File version strings**: Multiple version constants exist (`DDASFILEVERS`, `FLOATDATAVER` both equal "Ver 500"). These must match when reading/writing files.

5. **Hardware type encoding**: `FileTypeFlags` in `FILEINFOBLOCK` uses a split 16/16 bit encoding. Direct comparison of this field without masking will produce incorrect results.

### API Quirks
6. **Pointer-based buffer access**: `CDataFloat::GetDataBuffer()` returns a raw pointer to internal data. The state of this pointer after `SetSize()` or `ClearAll()` calls is unclear from the source—callers should re-fetch after modifications.

7. **Multiple channel number methods**: Both `GetChannelNumber()` and `GetChannelNumberInBox()` exist. The distinction between "channel number" and "channel number in system" is not fully explained in the source.

8. **Missing `TransducerDefinition.h`**: The `TRANSDUCER` type is used but not defined in the provided sources. The size