# Hub Module Wiring
Work inside the distribution panel must be carried out by a qualified electrician in accordance with local regulations. De-energize the panel before connecting conductors.
This guide covers Voldeno Hub (HUB-A-D-1) wiring: the bus connector, the Ethernet link, the termination switch and the checks to run once the panel is powered. Electrical ratings and mechanical data are on the HUB product page.
# Module overview
The Hub is the module every installation starts with. It stores the project configuration and automation logic, and it is the network interface Voldeno Studio talks to.
| Area | Detail |
|---|---|
| Field inputs and outputs | None. Field circuits connect to I/O, RELAY and sensor modules |
| Bus | 1 × Voldeno Bus: 24 V DC supply, GND, CAN-FD (BUS+, BUS−) |
| Network | 1 × Ethernet, to the LAN segment used by Studio |
| Mounting | 4 DIN units on a 35 mm rail |
Because the Hub has no field terminals, its wiring is limited to the bus connector and the Ethernet cable. Everything a load is connected to is described in I/O module wiring and RELAY module wiring.
# Terminal map
The Hub uses the same four-pair bus connector as every other DIN-mounted module. Each pair carries two wires: an Input (left) and an Output (right) position, electrically shorted inside the module, so a pair works as a pass-through point in the daisy chain.
| Terminal pair | Function | Input (left) | Output (right) |
|---|---|---|---|
| 24V | 24 V DC supply | From the power feed | On to the next module |
| GND | Ground | From the power feed | On to the next module |
| BUS+ | CAN High | From the previous module | On to the next module |
| BUS− | CAN Low | From the previous module | On to the next module |
The connector is a WAGO 235-454/331-000 push-in terminal. Use 0.2 … 0.75 mm² (24 … 18 AWG) single-wire conductors stripped to 9 … 10 mm; 0.5 mm² (20 AWG) is the recommended size for both the CAN pair and the 24 V distribution.
# Powering the Hub
The Hub draws its 24 V DC from the bus connector, exactly like an extension module. It has no separate supply terminals.
Feed the Hub from the dedicated 24 V feed of the cabinet row it sits in rather than from a chain that crosses the whole panel. Power supply sizing and distribution covers how to split the feeds and how to check the voltage that actually arrives at the terminals.
# Bus termination
The Hub is a 4-DIN module, so its termination switch is on the bottom of the enclosure. Left is ON, right is OFF.
Set it to ON only if the Hub is physically the first or the last module on the bus. A bus needs exactly two terminations, one at each end. If the Hub sits in the middle of the chain, leave the switch OFF. The full rule, including what happens when you get it wrong, is in Bus topology and wiring.
# Ethernet
Connect the Ethernet port to the LAN segment that Voldeno Studio runs on. The link is used for configuration, firmware updates and, if you enable it, remote access through Voldeno Cloud.
Automation logic runs on the modules themselves, so the installation keeps working when the network or the internet connection is down. The Ethernet interface also carries TCP, UDP and HTTP(S) integrations without an additional gateway module.
# Where configuration and data live
Project configuration, logic blocks and automation rules are stored in the Hub's onboard flash memory. Historical and operational data is written to the SD card, which is what makes diagnostics possible without an external server.
# Commissioning check
- Power on the 24 V supply and allow 2-5 seconds for the modules to boot.
- Open Voldeno Studio and confirm the Hub and every extension module appear in the connected devices list.
- Read the module terminal voltages in Studio and confirm they are within tolerance at the far end of each row.
- Toggle one relay output to confirm bidirectional communication.
If a module is missing from the list or drops out intermittently, work through Bus communication troubleshooting.