You are viewing an old version of this page. View the current version.

Compare with Current View Page History

« Previous Version 2 Current »

New Tasks per Requirement:

R-DM-001

  1. Create a master Data Dictionary spreadsheet or table (CSV + LaTeX version) with required columns:

    • Signal name

    • Source subsystem (sensor / MCU / OBC)

    • Units

    • Bit depth

    • Nominal rate (Hz)

    • Priority class (HIGH / MED / LOW / DEBUG)

    • Packet class

    • Storage file type

    • Notes (calibration, scaling, edge cases)

  2. Enumerate every signal mentioned in:

    • Section 6.1 (preliminary signals)

    • Fault and event logs

    • MCU diagnostics

    • Command acknowledgements

  3. Assign unique IDs for each signal (numeric or enum-based).

  4. Define scaling rules (e.g., raw ADC → physical units).

  5. Produce:

    • A LaTeX table for the Design Book (CoDR-ready)

    • A machine-readable version (CSV / JSON) for firmware use

  6. Add a versioning scheme and changelog.

R-DM-002: DM shall guarantee timestamp accuracy to within 10 ms of OBC master time

Owner: Time & Sync Engineer

  1. Define the time synchronization packet format sent from OBC → Payload MCU:

    • Absolute mission time

    • Time since boot

    • Drift correction field

  2. Write a timing budget showing:

    • Link latency

    • MCU processing delay

    • Worst-case error margin < 10 ms

  3. Specify how often sync packets are sent (e.g., every N seconds).

  4. Define MCU-side logic for:

    • Applying offset corrections

    • Rejecting outlier sync packets

    • Preserving monotonic timestamps

  5. Produce:

    • Timing block diagram

    • Error budget table

    • One-page explanation for CoDR reviewers

R-DM-003: DM shall store at least 48 hours of full-rate science and housekeeping data

Owner: Storage & Capacity Analyst

  1. Compute data generation rates for:

    • Science

    • Housekeeping

    • Faults/events

    • Debug (if enabled)

  2. Calculate 48-hour storage requirement with:

    • No compression

    • With compression (if applicable)

  3. Add margin for:

    • File system overhead

    • Worst-case fault logging bursts

  4. Produce a storage budget table:

    • Bytes/sec

    • Bytes/hour

    • Total bytes / 48 hr

  5. Validate storage feasibility against:

    • Selected memory hardware

    • Power constraints

  6. Flag any risks or trades for PDR.

R-DM-004: DM shall support data compression for science data files

Owner: Compression & Data Reduction Lead

  1. Identify candidate algorithms (e.g., LZ4, DEFLATE).

  2. Benchmark (or estimate):

    • Compression ratio

    • CPU cost

    • RAM usage

    • Power impact

  3. Define:

    • Which data types are compressible

    • When compression is applied (real-time vs batch)

  4. Specify file format metadata:

    • Compression flag

    • Algorithm ID

    • Original length

  5. Write a clear decision rationale for CoDR:

    • Why compression is needed

    • Why chosen approach is acceptable

R-DM-005: DM shall implement three priority classes: HIGH, MEDIUM, LOW

Owner: Data Flow & Scheduling Lead

  1. Map every packet type to a priority class.

  2. Define queue behavior for each priority:

    • Max depth

    • Drop policy

    • Preemption rules

  3. Specify behavior during:

    • Downlink windows

    • Storage pressure

    • Power-limited modes

  4. Produce:

    • Priority flow diagram

    • Queue state machine

    • One example scenario (e.g., fault during science)

R-DM-006: DM shall detect and log data corruption

Owner: Data Integrity Engineer

  1. Define CRC or hash algorithm used in packets.

  2. Specify:

    • Where CRC is computed

    • Where it is checked

    • What happens on failure

  3. Create a fault code list for corruption events.

  4. Define severity levels and escalation logic.

  5. Design example FaultLog entries:

    • CRC fail

    • Malformed packet

    • Sequence mismatch

  6. Add test cases to V&V plan.

R-DM-007: DM shall provide a complete command dictionary and routing logic

Owner: Command & Interfaces Lead

  1. Enumerate all payload-relevant commands.

  2. For each command, define:

    • Command ID

    • Arguments

    • Valid ranges

    • Acknowledgement behavior

  3. Define routing paths:

    • OBC → MCU

    • MCU → subsystems

  4. Specify:

    • Invalid command handling

    • Retry / timeout behavior

  5. Produce a Command Dictionary table aligned with ICDs.

R-DM-008: DM shall recover data continuity after a payload MCU reset

Owner: Fault Recovery Engineer

  1. Define reset detection logic.

  2. Specify how:

    • Sequence IDs resume

    • Timestamps remain monotonic

    • Files are closed and reopened

  3. Define event markers for resets.

  4. Write a reset recovery flow diagram.

  5. Identify worst-case data loss window and justify acceptability.

R-DM-009: DM shall define and enforce onboard storage retention policies

Owner: Storage Policy Owner

  1. Define retention rules per priority class.

  2. Specify deletion order under storage pressure.

  3. Define thresholds for:

    • Warnings

    • Forced purges

    • Safe-mode transitions

  4. Create a retention policy table.

  5. Write example scenarios:

    • Storage fills during comms outage

    • Debug logs enabled accidentally

R-DM-010: DM shall provide Communications with packet structures for downlink

Owner: Comms Interface Lead

  1. Finalize packet header and payload definitions.

  2. Ensure packet sizes are compatible with:

    • Link MTU

    • Comms framing

  3. Provide:

    • Packet class definitions

    • Priority mapping

    • Downlink ordering rules

  4. Produce a packet specification document shared with Comms.

  5. Walk Comms through one full downlink example.

  • No labels