machineGroupControl/test/_output-manifest.md

machineGroupControl — Output Manifest

Per .claude/rules/output-coverage.md. Single source of truth for what MGC emits on Port 0/1/2, where the value comes from, and which test exercises it in populated AND degraded states.

Convention for missing values: keys are absent when the underlying source has not produced a value yet (pre-first-tick, no demand, no pressure). Once produced, a key may be explicitly null/undefined only in the documented degenerate cases below. The dashboard formatter must treat both absent and null/undefined as "no data" (display '—') — see the pct/num helpers in examples/02-Dashboard.json :: fn_status_split.

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Port 0 — process data

Built by src/io/output.js :: getOutput(mgc). Delta-compressed by outputUtils.formatMsg(..., 'process') — only changed keys appear in each emit.

Static fields (always emitted once MGC has been initialised)

Key	Source	Type / Range	Populated test	Degraded test
mode	mgc.mode (set via set.mode command; normalised by specificClass.setMode)	string ∈ {optimalControl, priorityControl, maintenance} (canonical camelCase)	commands.basic.test.js, ncog-distribution.integration.test.js	n/a — always set from constructor default
scaling	mgc.scaling	string ∈ {absolute, normalized} or undefined	commands.basic.test.js	dashboard-fanout (undefined → raw-rows shows '—')
absDistFromPeak	groupEfficiency.calcDistanceFromPeak (specificClass.js:132)	number ≥ 0 (η-points)	bep-distance-demand-sweep, group-bep-cascade, groupEfficiency.basic	groupEfficiency.basic test 7 (undefined when current = null)
relDistFromPeak	groupEfficiency.calcRelativeDistanceFromPeak	number ∈ [0,1] OR undefined for degenerate (homogeneous pumps)	bep-distance-demand-sweep, group-bep-cascade	groupEfficiency.basic tests 5/6/7 (undefined cases), dashboard-fanout test 11 (undefined → '—' display)
flowCapacityMax	mgc.dynamicTotals.flow.max (totalsCalculator)	number m³/s ≥ 0	totalsCalculator.basic, dashboard-fanout (post-setup)	absent until first equalize; dashboard-fanout (state A)
flowCapacityMin	mgc.dynamicTotals.flow.min	number m³/s ≥ 0	totalsCalculator.basic	same as above
machineCount	Object.keys(mgc.machines).length	integer ≥ 0	demand-cycle-walkthrough, ncog-distribution	n/a — always reflects current registration count
machineCountActive	filtered count excluding off/maintenance states	integer ≥ 0	demand-cycle-walkthrough, ncog-distribution	dashboard-fanout (state A: 0 active)

Conditional pressure-header fields (emitted only when equalize resolved a positive ΔP)

Key	Source	Type / Range	Populated test	Degraded test
headerDiffPa	mgc.operatingPoint.headerDiffPa (groupOperatingPoint.equalize)	number Pa > 0	groupOperatingPoint.basic, dashboard-fanout (state B/C)	dashboard-fanout (state A — absent)
headerDiffMbar	derived headerDiffPa / 100 when unitPolicy.output.pressure === 'mbar'	number mbar > 0	dashboard-fanout (state B/C)	absent when output pressure unit ≠ mbar — not explicitly tested

Dynamic measurement fields — pattern {position}_{variant}_{type}

Built by the loop at io/output.js:23-39. For each type×variant×position the container holds, one key is emitted only if the value is non-null.

Positions: downstream, upstream, atEquipment. Plus differential_<variant>_<type> when both downstream and upstream exist.

Predicted measurements MGC writes itself (via writeOwn):

Key	Source (write site)	Type / Range	Populated test	Degraded test
atEquipment_predicted_flow	handlePressureChange (specificClass:153), _optimalControl (specificClass:214), equalFlowControl (control/strategies:118), turnOffAllMachines (specificClass:297)	number, canonical m³/s converted to unitPolicy.output.flow	bep-distance-demand-sweep, dashboard-fanout (state B/C), ncog-distribution	dashboard-fanout (state A: absent), turnoff-deadlock (post-shutdown = 0)
downstream_predicted_flow	handlePressureChange (specificClass:156 — mirrors AT_EQUIPMENT for PS contract), turnOffAllMachines (specificClass:296)	same as above	implicit in bep-distance-demand-sweep getOutput	turnoff-deadlock (post-shutdown = 0)
atEquipment_predicted_power	same call sites as flow (specificClass:157, 213; strategies:117; specificClass:298)	number, canonical W converted to unitPolicy.output.power	bep-distance-demand-sweep, dashboard-fanout, distribution-power-table	turnoff-deadlock (= 0)
atEquipment_predicted_efficiency	_optimalControl (specificClass:221), equalFlowControl (strategies:122) — only when dP > 0 && bestPower > 0	number ∈ [0, 1] hydraulic η = (Q·ΔP)/P	bep-distance-demand-sweep, dashboard-fanout (state C)	absent when dP ≤ 0 or bestPower ≤ 0 — guarded but not explicitly tested
atEquipment_predicted_Ncog	_optimalControl (specificClass:224), equalFlowControl (strategies:125)	number, range 0..N where N = active pumps (SUM of per-pump NCog from bepGravitation.js:162 totalCog) — NOT 0..1; see project-mgc-bep-metrics-semantics	ncog-distribution (9 tests), bep-distance-demand-sweep, dashboard-fanout (state C)	dashboard-fanout normalizes by machineCountActive for display — tests 6/7/8/9/10

Measured pressures forwarded from children: MGC subscribes to each registered measurement child (specificClass.js:91-104) and re-emits the child's reading on its own MeasurementContainer. If a pressure measurement child registers at position downstream, MGC will emit downstream_measured_pressure on Port 0 the next time getOutput runs.

Key pattern	Source	Tests
<position>_measured_<type>	child measurement node forwarded via MeasurementContainer.emitter (specificClass:91-105)	indirect — group-bep-cascade.integration drives pressure events through registered children; not asserted as a named output key
differential_measured_pressure	computed when both downstream_measured_pressure and upstream_measured_pressure exist (output.js:33-37)	indirect via dashboard-fanout (used by fn_qh_point for header ΔP fallback)

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Port 1 — InfluxDB telemetry

Built by outputUtils.formatMsg(..., 'influxdb') — same getOutput source, different formatter. Emits the same key set as Port 0 with InfluxDB line-protocol tag/field discipline (cardinality rules per .claude/rules/telemetry.md).

Concern	Status
Keys	Identical to Port 0; the influxdb formatter (generalFunctions/src/helper/formatters/influxdbFormatter.js) decides which become tags vs fields.
Test coverage	None. No test file imports/asserts the influxdb formatter for MGC. Regression vector if a key is added/renamed without checking cardinality. Tracked.

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Port 2 — registration / control plumbing

Emitted on startup by BaseNodeAdapter (one message per node).

Topic	Payload shape	Source	Tests
registerChild	{ id: node.id, positionVsParent: <string> }	BaseNodeAdapter init — sends to upstream parent so it can subscribe to this node's measurements	structure-examples.integration, commands.basic.test.js test 5 (child.register) — receiver side

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Events emitted on mgc.source.measurements.emitter

These are NOT Port 0/1/2 emissions — they're in-process events that downstream EVOLV nodes (e.g., pumpingStation) subscribe to via the parent-child handshake. Listed here for completeness; covered by .claude/rules/telemetry.md rather than this manifest.

• flow.predicted.atequipment — fired on every writeOwn to flow/predicted/AT_EQUIPMENT
• flow.predicted.downstream — fired on every writeOwn to flow/predicted/DOWNSTREAM (the live aggregate the PS subscribes to)
• power.predicted.atequipment
• efficiency.predicted.atequipment
• Ncog.predicted.atequipment
• <type>.measured.<position> — re-emit of any registered measurement child

Documented in CONTRACT.md; tested indirectly via group-bep-cascade.integration.test.js and ncog-distribution.integration.test.js.

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Coverage gaps (open items)

These are known holes flagged during the 2026-05-14 governance review; not yet fixed but documented so they don't regress silently.

1. Port 1 (InfluxDB) has no dedicated tests. Any rename of a Port 0 key should add an explicit Port 1 assertion to prevent silent cardinality regressions.
2. headerDiffMbar only emitted when unitPolicy.output.pressure === 'mbar'. The fallback (non-mbar configurations) isn't explicitly tested.
3. atEquipment_predicted_efficiency absent-state isn't asserted. The dP > 0 && bestPower > 0 guard exists but no test pins the absence.
4. Forwarded measured measurements (<position>_measured_<type>) aren't asserted as named output keys — only their underlying behaviour is exercised.
5. scaling undefined behaviour — schema removed scaling.current for several modes; what MGC emits for those is implicit, not tested.

When any of these is closed, move the row up into the appropriate table and delete the entry here.