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parking_solution/wiki/concepts/entry-exit-readers.md
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julian bf37106c5c wiki: ingest GEE-QR-ER80 QR access reader datasheet
The reader on hand is a GEE-QR-ER80 QR/DataMatrix/1D barcode access reader
(not an EM4100 prox-card reader as first guessed). Interfaces: Wiegand 26/34,
RS-232, RS-485, USB, TCP/IP; 4-15 VDC; Linux-supported. Variant on hand: -Q-W
(QR scanner, Wiegand/RS-232/485).

This is the QR-ticket scanner the design already needed: a host-side reader
whose scans become read-bus events consumed by the (already-built) exit flow
and QR-permit path. Prefer RS-232/485 over Wiegand (Wiegand can't carry a
variable-length QR string; autonomy is moot with the no-ACL Dingtian).

New source + entity pages; updated ticket-encoding, entry-exit-readers, index.
Open (blocks the adapter): the RS-232/485 frame + baud (ASCII CR/LF expected).
2026-06-16 08:22:23 +02:00

2.3 KiB

type, tags, sources, updated
type tags sources updated
concept
parking
architecture
readers
parking-system-architecture
2026-06-14

Entry / Exit Readers

There are two populations of users, and they map to two integration paths. (See parking-system-architecture §8.)

  • Permit holders / subscribers — want hands-free/quick entry. Best served by reads reaching the controller directly (wiegand) so it can decide autonomously (works if host is down).
  • Casual / transient — printed ticket, pay-on-exit, or plate recognition. Inherently host-side identity sources (lpr-camera, QR/ticket scanner).

How reads reach the system

Reader type Who sees the read Decision by Offline autonomy
wiegand reader → UHPPOTE port The controller Controller (onboard card list) Yes — works if host down
Pure TCP/IP reader Host only Host, then UDP open to relay No — host on critical path
[[lpr-camera LPR]] / QR scanner Host only Host
gee-qr-er80 QR reader (serial) Host only Host (reads serial → read bus) No

Concrete host-side reader on hand: the gee-qr-er80 (QR over RS-232/RS-485). Note autonomy is moot here anyway — the current relay (dingtian-relay) has no onboard card list, so even a Wiegand reader would be host-decided. So we take the serial/QR path straight to the host's read bus.

Key points

  • Pure network readers are invisible to the uhppote-controller — it only generates events for its own terminals. For a pure-TCP reader, only the host can listen/decide/command; the controller is demoted to a commanded relay (onboard card DB + offline autonomy bypassed).
  • Check for a Wiegand output first — many "network" readers have both; wiring Wiegand in keeps autonomy + native event log.
  • Both models can share one relay (valid Wiegand read or host open in "controlled" mode), so one lane serves permit + casual.
  • Host-in-the-loop is good for fraud detection — two independent records (host's signed append-only-event-chain entry + the UHPPOTE remote-open event) should reconcile 1:1; any mismatch is an anomaly.

Autonomy caveat: with remote-host control enabled, the controller expects host comms every ~30 s or reverts to local control (Wiegand-on-board lanes only).