MSPeriodicActuals.bin
Binary telemetry log. Always present in .d/AcqData/. Records instrument diagnostic values (pressures, temperatures, voltages, charge states, etc.) at irregular intervals throughout the run. Field definitions are in the companion MSActualDefs.xml.
Status: Confirmed
File Layout
- Global header: 68 bytes.
- Record stride: 20 bytes (confirmed via file size arithmetic and sequential parsing on PXD004747 and PXD001310).
Record Layout (20 bytes, little-endian)
The layout has two variants depending on whether the instrument is a QQQ or Q-TOF. The ActualID and Time fields are always at the same offsets; the Value field position shifts.
QQQ variant (PXD004747, G6410A)
| Bytes | Field | Type |
|---|---|---|
| 0-3 | OccurrenceFlag | int32 (1 on first event for this ActualID in a block, else 0) |
| 4-7 | ActualID | int32 |
| 8-15 | Time | double (minutes) |
| 16-19 | Value | float32 or int32 (see DataType) |
Q-TOF variant (PXD001310, G6550A)
| Bytes | Field | Type |
|---|---|---|
| 0-3 | Value | float32 or int32 (see DataType) |
| 4-7 | ActualID | int32 |
| 8-15 | Time | double (minutes) |
| 16-19 | Padding | int32 (always 0, or int32 for DataType=3) |
DataType Mapping (from MSActualDefs.xml)
All DataType codes observed across QQQ (PXD004747) and Q-TOF (PXD001310) files:
| DataType | Value Type | Value Offset (QQQ) | Value Offset (Q-TOF) | Examples |
|---|---|---|---|---|
| 3 | int32 | offset 16 | offset 16 | Charge State (ActualID=57), Min Range (ActualID=361) |
| 5 | float32 | offset 16 | offset 0 | Capillary Current (QQQ, ID=10), Funnel DC (Q-TOF, ID=85) |
| 6 | float32 | N/A (not in QQQ) | offset 0 | Rough Vac (ID=29, ~0.52 Torr), Quad Vac (ID=30), Gas Temp (ID=27), Drying Gas (ID=34) |
- DataType=5 QQQ example: ActualID=10 (Capillary Current), value ~39 uA at offset 16.
- DataType=5 Q-TOF example: ActualID=85 (Funnel DC), value 4.76 V at offset 0.
- DataType=6 example: ActualID=29 (Rough Vac), value 0.52 Torr at offset 0. Physically plausible for a rough vacuum pump.
- DataType=3 example: ActualID=57 (Charge State), int values 0, 2, 3, 5, 7 at offset 16 (Q-TOF).
Unresolved
- Whether the QQQ/Q-TOF variant distinction is instrument-model-specific or encoded somewhere in the file header.
- DataType values beyond 3, 5, 6 are not observed in the two files checked. The full set of DataType codes in the Agilent schema is not known from the XML alone.