Domoticz

I have been experimenting with a couple of Dombus modules which are based on the existing RS485 2 wire system as used by the industrial Modbus protocol. I am attracted to the reliable non-RF aspects as my home has thick walls and although I now have stable zigbee and zwave networks I like the idea of a wired bus system. I am interested in opinions and comparisons of the 2 systems before I start major home alterations (wall channelling and conduit installation) to allow for wired communication.

I really like the Dombus stuff and it seems well supported and also economic. However it's quite niche and I wonder if it could be limiting in the future. It would be nice to hear the pros and cons of the 2 systems before I dive in.

To summurize:

• every DomBus can be reprogrammed, free-of-charge, in the future, by the manufacturer in Italy, to use Modbus RTU or DomBus protocol, so you can migrate from one protocol to the other

• Modbus is standard, well supported by many systems, and it's a master/slave protocol (a master device have to poll all slave devices in the bus to read their inputs/sensors, so it's good to control outputs and sensors that have to be read every minute or seconds)

• DomBus protocol is a proprietary multi-master protocol: when an input changes in the DomBus module, it immediately sends notification to the Domoticz controller. The same for temperature, counters, meters: when data is available, it's sent to the controller. In this way it's possible to use DomBus modules also with large alarm systems with hundreds of sensors.

• DomBus protocol also permits to define one or more actions to take when an event occurs, similarly to KNX: for example, it's possible to configure a button connected to a DomBus module input so:
  • pushed less than 1 second => sends command to another DomBus module to toggle a relay output (to turn on/off a light.
  • If the button is pushed for about 1 second, sends command to some DomBus modules to turn OFF all lights.
  • If it's pushed for 2 seconds, send command to Domoticz to activate a scene (for example to activate the alarm in AWAY mode).
  These are just some examples of DCMD commands.