SEMI E39 — Object Services
SEMI E39 supplies shared object concepts and services used by GEM300 models. It provides a consistent way to identify objects, expose attributes, and perform common object operations through the equipment interface.
Area
GEM300
Profile coverage
300 mm Tool Standards · 300 mm Overhead Automation
Purpose
E39 prevents every automation standard from inventing incompatible object-management behavior. Standards such as process, carrier, substrate, and control-job management can build on common object identity and service conventions.
Where it applies
E39 becomes relevant when the selected GEM300 capabilities depend on its object model. It is part of the practical core profile shown here, but the exact services and subordinate mappings must follow the applicable standards and customer specification.
Who implements it
The equipment is typically the authoritative server for interface objects and their lifecycle. The host creates, queries, changes, and removes objects only through allowed services and must handle asynchronous state changes reported by the equipment.
Relationships and dependencies
- Builds on E30 GEM and E5 SECS-II.
- Provides common object behavior used by E40, E87, E90, and E94.
- Works with each domain standard rather than replacing its state models and rules.
Practical implementation guidance
- Use stable object identifiers and define ownership, lifecycle, persistence, and restart behavior explicitly.
- Keep object attributes synchronized with the equipment state that events and service responses expose.
- Test invalid transitions, duplicate identifiers, missing objects, and host recovery after reconnect.
Common mistakes
- Implementing generic CRUD while ignoring domain-specific state restrictions.
- Allowing host-visible objects to diverge from internal scheduler or material state.
- Deleting objects before required completion events and history have been reported.