The biggest single gap I called out in the GEM300 audit — closed.
E84 is the digital handshake between AMHS (Automated Material
Handling System) and the equipment for carrier load/unload. Unlike
the rest of GEM300, this isn't SECS messaging; it's a fixed set of
ten parallel boolean wires that follow a strict sequencing protocol
(E84-0710 §6.3).
Adds:
E84Signal enum CS_0/CS_1/VALID/TR_REQ/BUSY/COMPT/L_REQ/U_REQ/
READY/ES
E84SignalSet 10-bit bitmap with bool get/set
E84State Idle / CarrierPresent / ValidAsserted /
LoadReady / UnloadReady / Transferring /
Complete / EmergencyStop
E84StateMachine re-evaluates state on every signal change,
observable via set_state_change_handler
Joins EquipmentDataModel as `e84` (top-level — there's one per tool,
not per port). ES (emergency stop) dominates regardless of other
signals; COMPT and BUSY override the VALID-handshake states. Same
FSM drives real opto-isolated I/O lines (when wired through an
asio digital input adapter) and the back-to-back test simulation.
Six test cases cover the full load handshake trace (six transitions,
including the transient LoadReady-after-BUSY-drops state), the
unload variant via U_REQ, ES dominance + recovery, reset(), and
no-op suppression for idempotent signal writes.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
