Connectivity dependency map — farm systems (Demory farm site)¶
Purpose: Explicit dependency map : which farm systems must operate with no WAN , which degrade gracefully , and which must never be the only proof of animal / water welfare . Ties power (battery headroom ) to network (egress cost ).
Doctrine package: Off-grid systems doctrine package — Demory. WAN policy: Connectivity strategy — Claxton & Demory. SoR: Telemetry system of record — boundaries and authority.
Dependency table¶
| System / capability | No WAN | No LAN (isolated barn) | No field RF | Notes |
|---|---|---|---|---|
| Water pump interlock / dry-run protection | Must work | Must work if wired / local logic | N/A if not RF-dependent | Cloud must not gate safe state |
| Tank level — operator truth | Local indicator / sight / float required | Same | Mesh optional enhancement only | G8 / manual baseline |
| MQTT → cloud historian | Queues / drops (policy )** | Broker may be unreachable | Sensors may be dark | Not life-safety path |
| Starlink / LTE | Off is OK (sheddable )** | — | — | Wh budget item |
| farmOS cloud / hosted UI | Unavailable | Unavailable | — | Offline records discipline |
| Meshtastic / mesh text | Local mesh works | Partition possible | Degraded coverage | Not a substitute for rounds |
Mermaid — logical dependencies¶
```mermaid flowchart TB welfare["Welfare truth — local / physical first"] local_ctrl["Local control / interlocks"] field_rf["Field RF — mesh / LPWAN"] gw["Gateway / broker"] wan["WAN / Starlink"] cloud["Cloud / dashboards"]
welfare --> local_ctrl local_ctrl --> field_rf field_rf --> gw gw -. optional .-> wan wan -.-> cloud ```
Rule: Solid path from welfare to local_ctrl must never traverse wan .