---
type: entity
tags: [parking, hardware, readers]
sources: [parking-system-architecture]
updated: 2026-06-14
---

# Wiegand

The reader-wiring standard (Wiegand 26/34) used to feed reads **directly into the
[[uhppote-controller]]'s reader port**. This is the preferred path for **permit
holders/subscribers**, because it lets the controller **decide autonomously** from its onboard
card list — it keeps working even if the host is down. (See [[parking-system-architecture]] §8.)

- A door relay opens on **either** a valid Wiegand read on its reader port **or** a host `open`
  command — so one lane can serve permit holders (Wiegand, autonomous) and casual/[[lpr-camera|LPR]]
  (host command) on the same relay.
- **Tip: check for a Wiegand output first.** Many "network" readers (e.g. Nedap/UHF) have *both*
  a network interface and a Wiegand output. Wire the Wiegand output into the controller and you
  keep autonomous decisioning + the native event log, sidestepping host dependency.
- Autonomy caveat: if remote-host control is enabled, the controller expects host comms at least
  every ~30 s or it reverts to local (onboard-card) control.

Contrast with host-side identity sources in [[entry-exit-readers]].