[Tecnologic]

Phase W5 of docs/web_plan.md (old G5, docs/plan.md section on the scope).

How the shared trigger works

cymon-lib publishes cymon.TriggerEvent when a capture triggers. An armed node that subscribes to it triggers at its next sample. So ScopeClient.multi_capture:

1. sets up every node with its channels; the period, length and pre-trigger part are the same on all nodes;
2. arms the other nodes on a condition that never holds (rising above 3e38), so only the event can trigger them;
3. arms the trigger node on the user's condition;
4. waits for all captures, then reads them.

Each node's time axis is 0 at its own trigger sample.

The nodes need the trigger ports on one subject. UNIMOC disables uavcan.pub/sub.cymon_trigger.id by default:

• trigger_ports checks the ports;
• set_trigger_ports writes them (default subject 220, free on UNIMOC);
• the API and UI then store and restart the nodes, because ports take effect at start.

Changes

• core/scope.py: the capture is split into setup, arm, wait and read; added multi_capture, trigger_ports and set_trigger_ports.
• API:
  • GET /api/scope/trigger?nodes=10,11;
  • POST /api/scope/trigger: operator only, refused while a node is engaged; stores and restarts the nodes;
  • POST /api/scope/capture: several nodes. Captures taken during a run are stored in it, one CSV per node with the variable names.
• Scope view:
  • nodes with their variables, the trigger node and its condition;
  • a check of the shared trigger, with Set up the shared trigger;
  • all channels in one plot (uPlot.join across nodes), CSV export.
• Demo device: trigger ports, publishes its trigger event, triggers on the events of others.
• SimInstance.start() after a stop() now waits for the new pseudo terminals; it returned with the old ones.
• README (Scope), web_plan.md status.

Tests

• tests/unit/test_scope.py: two demo devices. Covers the refusal without a shared subject, then setup and restart, then a capture where the trigger node fires on its condition and the follower on the event.
• tests/unit/test_web.py: the trigger endpoints (403 for viewers) and a two-node capture stored in a run.
• tests/browser/test_scope_ui.py: the whole flow in Chromium.
• tests/sim/test_scope_sim.py: the W5 acceptance test.
  • Two native_sim drives (nodes 10 and 11) with the trigger ports stored in their flash, joined into one bus by an slcan bridge in the test.
  • A capture on both with node 10 triggering.
  • The delay of the second drive, measured from the two trigger events: 3 to 21 ms here. Most of that is the Python bridge; on a real bus the plan expects 1 to 2 ms.
• Locally: ruff, format and mypy clean; pytest 122 passed, 1 skipped, against the released v0.3.0 native_sim.

---

Generated by Claude Code