Backup power (UPS)
Why we recommend powering boneIO Black from a 24 V UPS or buffered power supply.
Backup power (UPS) — recommended
Power boneIO Black from a 24 V DC supply with battery backup — a UPS or a buffered (DC-UPS) power supply. boneIO Black should see uninterrupted 24 V, even when the mains drops for a moment.
boneIO Black is a small Linux computer. It writes its configuration, logs and — during an update — system packages to its memory card or eMMC, and it has no battery-backed clock. Most of its unexpected restarts are caused by short brownouts on the mains. A few minutes on a battery covers them.
What a UPS gives you:
- No restart on a mains blip. Outputs, inputs and automations keep working through short cuts and voltage dips.
- The right time. After a power cut the controller does not know the time until its network is up and a time server answers. Until then schedules, sun events and time windows in conditions wait.
- Safe updates. A system update can take up to an hour on a controller that has not been updated for a long time. The display and the panel say Do not power off — a power cut in the middle of it is the one case that may need hands on the device to repair.
The choice of the unit is yours or your installer's. Two common setups:
- a DIN-rail 24 V DC-UPS module (or a power supply with a buffer and battery) in the cabinet, between the power supply and boneIO Black,
- a 230 V UPS feeding the 24 V power supply.
Either way the wiring to boneIO Black is the one in the picture above: +24V to + and GND to GND on the POWER terminal, coming from the UPS side.
Size it for everything on the same 24 V line, not just boneIO Black — relay coils, sensors and other devices powered from it count too.
boneIO Black copes better with a power cut since 1.6: it checks and repairs its file system at start, a damaged boot partition no longer stops it, and an interrupted package install is finished on the next boot. A UPS is still the recommendation — the controller does not shut itself down when the battery runs out, so the UPS is what keeps it running.