Design: Dimensions and Units Model (Groups 13/14 + AC/IC + DIAM*)

Task: T-042 (architecture/design)

Goal

Define Siemens-compatible architecture for:

• Group 14 modal absolute/incremental state (G90/G91)
• Group 13 unit state (G70/G71/G700/G710)
• per-value absolute/incremental overrides (AC/IC)
• rotary absolute targeting (DC/ACP/ACN)
• turning diameter/radius programming family (DIAM*, DAC/DIC/RAC/RIC)

This design maps PRD Section 5.8.

Scope

• state ownership and propagation through parse -> AIL -> runtime
• precedence rules for modal state vs per-value overrides
• model boundaries for units impacting geometry-only vs geometry+technology
• axis/channel policy hooks for turning diameter/radius semantics
• integration touchpoints with feed and plane/compensation states

Out of scope:

• full machine-data database implementation
• controller-specific cycle internals and kinematic solvers

Pipeline Boundaries

flowchart LR
  A[G90/G91/G70/G71/G700/G710/AC/IC/DC/ACP/ACN/DIAM*] --> B[Parser + Semantic]
  B --> C[Modal Engine]
  C --> D[AIL Lowering]
  D --> E[AilExecutor]

  P[MachineProfile + DimensionPolicy] --> C
  P --> E

• Parser/semantic:
  • parses modal words, overrides, and axis-value forms
  • validates grammar shape and impossible combinations in one block
• Modal engine:
  • holds Group 14 and Group 13 persistent state
  • resolves effective interpretation mode per value (modal + local override)
• AIL/executor:
  • carries normalized interpretation metadata for motion/assignment consumers

State Model

Group 14 (modal distance interpretation):

• g90: absolute
• g91: incremental

Group 13 (modal units):

• g70 / g71: geometry-only unit switch
• g700 / g710: geometry + technological-length unit switch

Per-value overrides (non-modal value decorators):

• AC(...): force absolute for the decorated value
• IC(...): force incremental for the decorated value

Rotary absolute targeting (non-modal):

• DC(...): shortest-path absolute rotary target
• ACP(...): positive-direction absolute rotary target
• ACN(...): negative-direction absolute rotary target

Turning diameter/radius family:

• channel/axis mode words (DIAMON, DIAMOF, DIAM90, DIAMCYCOF)
• axis-value forms (DAC(...), DIC(...), RAC(...), RIC(...))

Precedence Rules

1. Effective value interpretation starts from modal Group 14.
2. If a value has AC/IC, that local override wins for that value only.
3. DC/ACP/ACN apply only to rotary-target forms and do not modify Group 14.
4. Diameter/radius forms apply only on profile-eligible axes.
5. Unit interpretation applies before runtime feed/planner consumption, with Group 13 scope deciding which quantities are unit-switched.

Unit Scope Model

• G70/G71:
  • affects geometry quantities (positions, arc data, pitch, programmable zero offset geometry terms, polar radius)
  • does not directly switch technological feed-length interpretation
• G700/G710:
  • affects geometry quantities plus technological-length quantities
  • must couple with feed model consumers

flowchart TD
  U[Group 13 state] --> S{Geometry only?}
  S -- yes --> G[apply to geometric fields]
  S -- no --> G2[apply to geometric + technological length fields]

Axis/Channel Policy Hooks

Machine/profile configuration should provide:

• axis eligibility for diameter/radius semantics
• channel turning-mode defaults
• rotary-axis targeting constraints for DC/ACP/ACN
• conflict behavior policy for mixed incompatible decorators in one block

Invalid policy cases (examples):

• DAC(...) on non-turning axis -> diagnostic and ignore value
• incompatible rotary decorators in same value -> diagnostic

Integration Points

• Feed model (T-041):
  • Group 13 broad-unit mode (G700/G710) influences feed-length semantics
• Working plane (T-040) and tool compensation (T-039):
  • axis/plane interpretation of center and compensated paths consumes effective dimension interpretation metadata
• Work offsets (T-043):
  • coordinate-frame selection/suppression occurs independently from absolute/incremental and units interpretation, then composes in runtime

Output Schema Expectations

AIL modal-state concept:

{
  "kind": "dimension_state",
  "group14_mode": "g90",
  "group13_mode": "g710",
  "source": {"line": 80}
}

Value-level effective interpretation concept:

{
  "axis": "X",
  "effective_distance_mode": "incremental",
  "mode_source": "local_ic",
  "effective_unit_scope": "geometry_and_technology"
}

Rotary targeting concept:

{
  "axis": "C",
  "target_mode": "absolute_positive_direction",
  "source_decorator": "ACP"
}

Policy Interface Sketch

struct DimensionPolicy {
  virtual EffectiveDimension resolve(const ModalState& modal,
                                     const ValueContext& value,
                                     const RuntimeContext& ctx,
                                     const MachineProfile& profile) const = 0;
};

Implementation Slices (follow-up)

1. Modal-state completion

• finalize Group 13/14 representation and transition handling

2. Value-override lowering

• normalize AC/IC and rotary decorators into explicit value metadata

3. Diameter/radius policy wiring

• enforce axis eligibility and emit deterministic diagnostics

4. Feed/plane coupling

• integrate unit-scope effects with feed and plane consumers

Test Matrix (implementation PRs)

• parser tests:
  • valid/invalid Group 13/14 transitions and decorator syntax
• modal-engine tests:
  • Group 14 persistence + per-value override precedence
  • Group 13 scope behavior contracts
• AIL/executor tests:
  • stable effective metadata for distance/unit/rotary modes
  • diameter/radius policy diagnostics by axis eligibility
• docs/spec sync:
  • update SPEC sections for dimensions/units/turning semantics per slice

Traceability

• PRD: Section 5.8 (dimensions, units, rotary targeting, DIAM*)
• Backlog: T-042
• Coupled tasks: T-041 (feed), T-039 (comp), T-040 (plane), T-043 (offsets)