---
type: entity
tags: [parking, hardware, access-control, relay]
sources: []
updated: 2026-06-15
---

# Dingtian Relay Controller

A network **relay + input** board (the unit on hand is the **4-channel** variant: 4 relays + 4
inputs). Chosen to drive the entry/exit lane because — unlike the [[uhppote-controller]] — its
**inputs are independent of its relays**, which solves the [[access-controller-button-flow]]
blocker (a button on an input does not auto-open a relay; the host decides).

SDK: `dingtian/4ch/sdk_v2_0_0/` (programming manual, examples). MIT-compatible use; no vendor
runtime needed.

## ⚠️ The one gotcha: `input_link_relay`

By **default the device links each input to auto-fire its matching relay** (`input_link_relay: 1`,
`on_action_on: [[0],[1],…]` in the config) — i.e. the *same* auto-open problem as the UHPPOTE.
The difference: **it is configurable.** Set `input_link_relay: 0` (or clear the action mappings)
so an input only *reports* and the host commands the relay. **This config step is mandatory** for
the ticket-first entry flow. See [[autonomous-direction]].

## Protocol (Dingtian string — what we use)

Transport options: UDP/TCP string, UDP binary, HTTP CGI, Modbus, MQTT. We use **HTTP + UDP** —
see [[dingtian-vs-mqtt]].

- **Relay control — UDP ASCII, port 60001:** `1`+ch = ON, `2`+ch = OFF, `T`+ch = toggle.
  Pulse/jog `11*` (default 500 ms), delay `11:30` (30 s then off), flash `11F5`. `X` = all relays.
  Intent-only pulse for a barrier = `pulseOpen` ([[barrier-not-a-door]]).
- **Status / inputs — send `00`** → `「relays」:「inputs」:「count」`, e.g. **`0000:1111:4`** (4ch:
  relays off, inputs high). `0` = OFF/Low, `1` = ON/High. Poll-based.
- **Input push — `input_link_url`:** device **HTTP POSTs to a host URL on input change** — the
  push path for button events without a broker.
- **Discovery:** UDP multicast `224.0.2.11:60000`, send `\x05\xAA` (devices reply). Defaults:
  IP `192.168.1.100`, UDP `60000` (binary) / `60001` (string).
- Binary protocol (port 60000) adds optional **password** + multicast; bitmask relay/input maps.

## Status

Protocol understood from the SDK; **driver + on-hardware test not built yet**. Next: a `dingtian`
relay driver in [[device-registry]] (UDP control + status parse) and the input-push endpoint,
with `input_link_relay` disabled on the device. Needs the device IP + LAN to test.