Frequently asked questions
What the price includes, what it doesn't, and how the configurator works it out.
Most smart home calculators give you a range and ask for your email. This one gives you part numbers. The module prices are read from our shop as you configure, so the figure matches what the cart will charge — not an estimate that a salesperson revises later.
It also works out the panel. You get the DIN rail layout, the enclosure size in millimetres, the number of RS-485 segments and how many controllers they need, the 24 V power budget, and the count of breakers and terminals. Nobody else calculates the enclosure.
Every configuration has its own link, so you can send your exact result to an installer and they open the same thing with current prices. And because the modules run ESPHome, the configurator also writes the Modbus timing values you will need — the ones that, left at their defaults, quietly stop a long bus from polling every device.
Every switched circuit needs an output. A ceiling light, a pump, a towel rail — each takes one relay channel. A DIO-430-R1 gives you three, so twelve light groups need four modules. Dimmable circuits are different hardware: phase-cut dimming needs a DIM-420-R1, two channels per module, and most LED drivers require trailing edge rather than leading. Roller shutters are the item people underestimate — a shutter motor needs two interlocked relays, so one module drives one shutter. Underfloor heating works the other way round: thermal actuators run from MOSFET outputs, and one STR-3221-R1 handles up to 32 loops.
Modules talk over RS-485 Modbus RTU to a controller — a MicroPLC or a MiniPLC. Which one you need is a question of channels, not size: the MiniPLC has six relays, four analogue inputs and two RTD inputs of its own, so it sometimes replaces a whole module. Since ESPHome 2026.7.0 the default Modbus timings can leave a long chain of modules silently unpolled, so the configurator splits the bus into segments and writes the required timing values into the ESPHome configuration it generates.
Modules are not the largest thing in the enclosure — terminals are. Every field wire lands on a terminal before it reaches a module, and a house with thirty circuits easily runs to two hundred. Add one protective device per switched circuit, neutral and earth busbars, a 24 V supply for module logic and a separate one for every module driving LED strip. What the configurator does not price is the 230 V side: breaker ratings depend on the load and local regulations, cable sizes on run length. It counts the quantities and reserves the space, but leaves the ratings for the electrical design. Installation labour is not included.