The most important point to consider for your home automation is availability.

You can't do anything if your system is not available, then all your comfort is gone, your investment becomes worthless and your frustration will be high.

And Murphy will make sure that any breakdown will come at the worst possible moment.

Therefore it is so important to choose for a reliable and resilient system without SPOFs (Single Point of Failure), and a distributed system provides just that. Expressed in terms of availability, you should aim at 5 nines, or 99,999% uptime, which means less than 6 minutes of downtime per year. This is better than what the electricity companies can provide on the grid.

And the other aspect ”maintenance” has also a big impact on availability, therefore it is important that maintenance activities can be performed on a live, working system. Live replacement of components when needed should not impact the rest of the working configuration. Well, with Velbus and our redundant power supply, we make this happen.

Of course, the whole home is dependent on mains supply, usually from the grid, and it is not common practice to have a no-break system in a non-critical environment such as the classical home. However, even when the grid fails to provide mains supply, it is still interesting to keep status of the home automation components until mains supply recovers. This will automatically bring back all appliances in their status of just before the outage. Our module provides the option to connect a battery to make this happen. Normally speaking we're dealing with short outages, the duration that the battery can keep the Velbus system statuses depends on its capacity (standard we foresee about 1 or 2 hours, but with a larger battery one can last longer).

Power supply redundancy is important for home automation systems because it ensures that the system continues to function even if one of the power sources fails. This is achieved by using multiple power sources, such as a backup power supply that automatically kicks in if the primary power source fails (with the important environmental and energetic aspect that the backup power supply is not consuming energy nor creating heath or wear out as long as it is in its standby status), it remains unpowered if not in use. This is important because home automation systems controls your critical systems such as security, lighting, and heating, and a power failure could result in these systems not functioning properly, which could be a safety or security concern as well as an important discomfort. Additionally, power redundancy can also improve the reliability and uptime of the home automation system, which is important for the overall performance and user experience.

On top of the provision for high availability, the SOLIVI module monitors the mains voltage and triggers the RCD (residual-current device) if it should exceed the acceptable level. This feature protects not only the Velbus system, but also all circuits which are downstream of the RCD, hence the advantage to put the Velbus system mains access just after the very first / main RCD because then the whole building is protected.

As we speak about high availability, it is important to understand that the Velbus system is based on a distributed topology.

Let's explain more in detail Centralized / Distributed / Hybrid:

A distributed topology for a Velbus system refers to a CANbus based architecture in which devices are connected to the bus in a decentralized manner, with no single point of control or failure. This allows for greater availability, flexibility and scalability, as new devices can be added or removed from the network without disrupting the entire system.

A centralized topology, on the other hand, refers to a network architecture in which all devices are controlled by a central hub, server or CPU. This approach can simplify the overall system design and management, as all devices can be controlled and monitored from a single location, but it has a major drawback on the system availability because it is a single point of failure.

Benefits of a distributed topology:

• Resilience: In a distributed topology, if a device fails, the other devices can continue to work.
• Scalability: A distributed system allows for more flexibility in adding new devices and expanding the system as needed.
• Lower Latency: In a distributed topology, devices can communicate with each other directly, rather than having to go through a central hub. This can lead to lower latency and faster response times.
• Final result = high availability, and in our particular situation it can reach five 9s or 99,999% or less than 6 minutes of downtime per year (look into the CANbus text as well)