Semi E87.1

SEMI E87.1 defines the SECS-II message set that carries SEMI E87's Carrier Management System (CMS) data between equipment and host — E87 defines the carrier-tracking data model (carrier ID, location, slot-map status, access state), while E87.1 defines the actual wire-level messages a tool and host exchange to move that data automatically. Without E87.1, E87's CMS model would describe what a carrier-tracking system needs to know in the abstract, but a host would have no standardized way to actually request carrier ID and slot-map data from a tool or receive carrier-event notifications as they happen — E87.1 is the protocol binding that turns the CMS data model into real SECS-II messages, the same role E58.1 plays for E58's ARAMS model.

The reason carrier management needed its own SECS-II protocol spec rather than reusing a generic event message is that carrier tracking depends on precise, consistently-coded data — carrier ID format, slot occupancy encoding, access-state values — and if two tool vendors encode that data differently, a host's carrier-tracking logic either breaks or needs custom per-vendor parsing. A fab tracking lot genealogy and carrier location across a mixed-vendor tool fleet needs every tool's carrier-arrival and slot-map reports to arrive in the same message structure with the same field encodings, which is exactly the integration cost E87.1 eliminates — standardizing the SECS-II layer underneath E87's data model, not just the category definitions the data model itself describes.

E87.1 is the piece that makes carrier and lot-genealogy tracking automatic across a mixed-vendor fleet rather than a per-tool integration project — the same relationship E58.1 has to E58, applied to carrier data instead of reliability data.