System devices are your business-wide gear — the hardware that runs your location rather than a single room. Lobby lighting, the open/closed sign out front, waiting-area music, schedule-driven equipment: these all live at System → Devices, where ARC describes them as “Shared endpoints and signals used across your business.” They’re available to your business-wide automations and scenes, and they stay available no matter which rooms are running.
Looking for the props inside a single game?
Those are game devices — the maglock on a final door, a reed switch on a drawer, the puzzle hardware that belongs to one room. This page is about location-wide gear that isn’t tied to any one game. Both kinds ride on the same connections; only the scope differs.
What belongs in System
Use a System device for anything that serves your building as a whole:
- Lobby and waiting-area lighting you want on a schedule or under one switch.
- Signage — an open/closed sign, a “session in progress” light, a queue display.
- Background music for shared spaces.
- Schedule-driven gear — anything that turns on at opening and off at closing.
- Location-wide sensors — a front-door contact, an occupancy sensor for the lobby.
If the device is part of one room’s puzzle flow, it’s a game device instead. A clean split keeps each game’s editor focused on that room and keeps your shared infrastructure in one place.
Connections come first
Every device — System or game — rides on top of a connection, the protocol bridge that lets ARC speak to it. You add the connection once at System → Connections, then add devices to it. If the bridge for a protocol isn’t in place, ARC has nothing to attach the device to, so set up the connection first.
Device kinds
When you add a device, ARC asks what kind it is. The kind tells ARC how the device behaves on its connection. These are the kinds you pick from the Add device list.
| In the Add device list | Built on | What you configure |
|---|---|---|
| MQTT Device | An MQTT connection | A topic for the device. Basic mode is read-only; Advanced mode adds properties and commands so ARC can also control it. |
| PLC Device | A PLC (Modbus) connection | One Modbus address mapped to this device — read or write a coil or register. |
| DMX Device | A DMX connection | Map named channels to DMX addresses. |
| Z-Wave Device | A Z-Wave connection | Pick the node and the value to use — contact sensor, motion, switch, dimmer, button, temperature, or humidity. |
| Zigbee Device | A Zigbee connection | Pick the paired device and a capability — button, power, brightness, color, contact, motion, temperature, and more. |
| Hue Device | A Hue connection | Choose a light, scene, or group from the connected Hue bridge. |
| OSC Endpoint | An OSC connection | Listen for or send OSC messages at an address. |
The list depends on your connections
The picker splits the types into Ready to add and Needs a connection. A type you have no connection for stays in the second group with a note like “Add a Z-Wave connection first.” and a Set up connection shortcut. If you have no connections at all, the page says Add a connection first and offers a Go to Connections button.
Kinds that find themselves
Some devices never appear in the Add device list — ARC discovers them and you approve them instead. They show up in the list as Pending; click one to review it and add it.
- Bluetooth — a Bluetooth sensor or button (such as a Shelly BLU) seen by a Bluetooth Gateway.
- Kasa — a TP-Link Kasa smart plug found on your network.
Two more kinds are created for you and can’t be added by hand: Room mic (a microphone streamed in by a Raspberry Pi or an ESP32) and Display bridge (a screen driven by a Raspberry Pi or Windows Bridge — see Raspberry Pi and Windows Bridge).
GPIO pins are game-scoped
The Raspberry Pi (GPIO) device kind — bundling a Pi’s physical pins into a device — is only available inside a game’s Editor → Devices, because GPIO props belong to a specific room. The Pi’s Display and Bluetooth roles can still serve location-wide gear.
Add a System device
Here’s the general flow. The details differ by kind — an MQTT device asks for a topic, a Z-Wave device asks you to pick a node — but the shape is the same.
- Go to System → Devices.
- Click to add a device, then choose the device kind that matches your hardware.
- Select the connection this device talks through.
- Fill in the kind-specific details — for example a topic, a node and value, or a Modbus address.
- Give the device a clear name your staff will recognize, like "Lobby Sign" or "Waiting-Room Music."
- Save. The device appears in the list with a status badge and, where supported, live telemetry.
Device status badges
Each device shows a status badge so staff and builders can see its state at a glance.
| Badge | Meaning |
|---|---|
| Active | The device is connected and reporting normally. |
| Idle | Connected but quiet — no recent activity. |
| Pending | ARC is waiting on the device — being set up or not reporting yet. |
| Ignored | Intentionally set aside so it doesn’t affect status. |
| Error | Something is wrong — the device or its connection isn’t responding as expected. |
| Inactive | Turned off or not currently in use. |
Watch for Error and Pending
An Error or stuck Pending badge usually means a connection problem — a broker that’s down, a controller that’s unplugged, or a device that’s lost power. Resolve these so your lobby gear and signage behave as expected, especially around opening time.
Live telemetry
Where a device supports it, ARC shows live telemetry next to its status so you can spot trouble early:
- Online / Offline — whether ARC can currently reach the device.
- Last seen — the timestamp of the most recent signal, useful for catching a device that quietly dropped off.
- Battery % — remaining charge on battery-powered devices, so you can swap batteries before a sensor dies.
- Signal (dBm) — wireless signal strength, which helps you find devices that are too far from their gateway or controller.
Not every device reports every field — telemetry depends on the device kind and what the hardware sends.
Where to go next
- Connections — add the protocol bridge a device rides on.
- System automations and scenes — put your location-wide devices on schedules and reactions.
- Game devices — the props and hardware inside a single room.