Readers.
RFID readers generate high-volume observation data at fixed and handheld read points. EPCIS 2.0 is the layer above the reads: the standardized event, not the raw stream. The gateway accepts the events, stamps the warrantor, grades the asserted observer, and appends.
POST /capturePOST /translate
A tunnel's shift, as events.
read point: tunnel-2 · 06:00–14:00 · 4,180 tag reads
→ ObjectEvent observing ×4 (one per batch, not one per read)
"readPoint": { "id": "https://id.gs1.org/414/0950600013460/254/T2" },
"who": "did:thing:tunnel-2", // asserted, graded
"spine:capturedBy": "acct:plant-il-3" // stampedIllustrative: a fixed reader run at line speed. The observer is the tunnel itself — an embodied agent, asserted and graded like any other observer; the plant's account is the stamped warrantor.
For the engineer between the reader and the record.
The raw read stream is not the record; the standardized event is. Batching reads into events is your call at the edge — what the door guarantees is that every event that clears it validated against the official schema and carries both grains, whichever hardware produced the reads.
Proof, not adjectives. The gateway's conformance tests pass against GS1's normative artifacts. See How for the dimension, and What ships today for the dated ledger.