Smart PIERRE - IO Sync (Overview)

What can be synced

IO Sync synchronizes user-controlled settings (“control fields”):

• mode (e.g., on/off, heat/cool)
• target (e.g., temperature / setpoint)
• intensity (e.g., brightness / dim level)
• color
• colorTemp (color temperature)

If a device doesn’t support one of these fields, IO Sync will skip that field for that device.

What cannot be synced (by design)

System state fields are not synced

Some fields represent read-only system state, not user control. For example, active is not syncable.

Window coverings are not supported

Window coverings (blinds/shades) often have complex motion states (opening/closing/stopped/calibrating), which can produce unreliable sync behavior. They are not allowed in sync groups.

Sync is local-only

Sync works only between local devices on the same controller instance. Remote/network devices are not eligible.

Why: distributed propagation can create feedback loops and timing races that are hard to prevent reliably across network boundaries.

Automations do not trigger sync

IO Sync responds only to direct user commands, not automation-triggered changes. If an IO in a sync group has an automation (e.g., a schedule or sensor trigger) that changes its state, only that IO will change—the other IOs in the group will not sync.

Example: A sync group of 5 lights where one light has a motion-sensor automation:

• When motion is detected, only that one light turns on
• The other 4 lights remain off
• The sync group is now "out of sync"

This behavior may be used intentionally (e.g., to create exceptions within a group), but requires careful planning.

How syncing behaves

• Bidirectional: changes can originate from any device in the group
• Multi-device: groups can contain more than two devices
• Fast: local propagation is designed to be near-instant
• Deterministic conflicts: if two changes happen at nearly the same time, the system converges using last-write-wins
• Loop-safe: the system avoids endless back-and-forth updates

Setup model (simple rules)

Each device can belong to one sync group (multi-sync is not supported). A sync configuration defines:

1. the other devices in the group
2. the fields to keep synchronized

If one device is unavailable, the system continues syncing the remaining available devices.

Mermaid Diagrams

Supported I/O Types

• Lights
• Dimmable Lights
• Fans
• Electric Outlets
• RGBCW Lights
• RGB Lights
• RGBW Lights
• Valves
• Water Heater

Blinds, curtains and shaders are not offered in the Sync tab.

Supported Synchronisation Fields

All five fields — Mode, Intensity, Target, Colour Temperature and Colour — are always offered. Select only the fields that the devices in the group support; a field that a device does not have is simply ignored for that device. One or more fields can be selected, depending on the behaviour required.

System Requirements

IO Sync only works between I/Os connected to the same bridge. Supported bridges:

• PIERRE Controller
• PIERRE Display
• PIERRE Gateway

I/Os connected to different bridges cannot be synchronised with IO Sync, even when they are in the same room.

Configuration

The Sync tab is available to Partner accounts only. End users do not see it.

1. Sign in to the Smart PIERRE application with a Partner account.
2. Press and hold the card of one of the I/Os to open its settings.
3. Open the Sync tab.
4. Under I/Os to sync, choose the other I/Os.
5. Under Fields to sync, tick the fields that must stay equal.
6. Save. The other I/Os are linked back automatically, so the group is complete without opening each one.

To change a group, open the Sync tab of any member, adjust the I/Os or fields and save again. To dissolve a group, open the Sync tab of any member and press Delete. This clears the sync setting on every member.

Operation and Timing

• The synchronisation runs inside the bridge, so it keeps working without an internet connection. Creating, changing or deleting a group needs the cloud.
• Rapid repeated changes are grouped together. The first change is applied immediately; further changes within about a second are collected and applied once, so the group can lag the last command by up to a second.

Rules

• The group does not align the devices when it is created. They become equal at the first change after saving.
• If a member is unreachable when a change happens, the other members still follow. The member that was unreachable is not brought up to date afterwards.

Technical Notes

• Check the bridge assignment before promising synchronised behaviour. Two lights in the same room may sit on different bridges, and no configuration will link them. Re-pair the device to the right bridge first.
• For on/off switches tick Mode only. For dimmers tick Mode and Intensity.

Step-by-Step Example: Three Hallway Lights

A hallway has three Wave light switches, Hallway 1, Hallway 2 and Hallway 3, all paired to the same PIERRE Display. The customer wants any switch to control all three lights.

1. Check the bridge. In the PIERRE Partner application open the display and confirm that all three switches are listed under it. If one is paired to a different display or gateway, re-pair it first; otherwise it cannot join the group.
2. In the Smart PIERRE application, signed in as Partner, press and hold the Hallway 1 card.
3. Open the Sync tab.
4. Tap I/Os to sync and tick Hallway 2 and Hallway 3. Confirm.
5. Under Fields to sync tick Mode only. Leave Intensity, Target, Colour Temperature and Colour unticked, because these are on/off switches.
6. Save.
7. Test. Press the wall switch of Hallway 2. Hallway 1 and Hallway 3 switch on within about a second, and the three cards in the app show the same state. Switch Hallway 3 off from the app. All three go off.
8. Open Hallway 2 or Hallway 3 and check the Sync tab. Each already lists the other two, which confirms the group.

Variant: Two Dimmable Lights

Two dimmable lights must always show the same brightness. Follow the same steps, but tick both Mode and Intensity. Setting one light to 50 % then sets the other to 50 % as well. If the customer wants to dim one light on its own occasionally, tick Mode only.

Removing the Group

Open the Sync tab of any of the three lights and press Delete. All three lights return to independent operation.

1) High-level: one device change propagates to the group

2) Example: 5 hallway lights synced on mode

3) Example: switch + lamp (different device types)

4) Example: thermostats synced on target

5) Local-only rule (what’s allowed vs not allowed)

6) Loop-safe behavior (conceptual)

This shows why sync doesn’t “bounce” forever: once everyone already has the value, propagation stops.

Availability

IO Sync is currently available only to partners due to the behavioral limitations described above (particularly around automations). This ensures proper setup and user expectations.