Gateway uplinks & network configuration

A gateway reaches Synacl over an uplink: wifi, ethernet, or cellular. Gateways with a W5500 Ethernet module can run Wi-Fi and Ethernet at the same time — the Network button on the gateway's card in Gateways (shown only when the gateway reports Ethernet support) controls how the second interface is used. Partners find the same control in the Diagnostics console.

Ethernet modes

• Auto (default) — probes the Ethernet port on boot; if a cable with a DHCP lease is present, Ethernet becomes the uplink, otherwise the gateway falls back to Wi-Fi.
• Uplink — forces Ethernet as the internet path (Wi-Fi is not used for internet, even if it's configured).
• LAN — the PLC scenario: Wi-Fi stays the uplink, and Ethernet becomes a local-only interface for reaching devices on an isolated segment (e.g. a PLC or industrial network with no internet route). Add a Modbus TCP device targeting the PLC's private IP once this is set.
• Off — never probes the Ethernet port.

Static vs. DHCP

• DHCP (default) — the Ethernet interface gets its address from whatever DHCP server is on that segment.
• Static — set manually: IP address and subnet mask are required; gateway and DNS are optional (leave them blank on an isolated PLC segment with no router of its own). Use static addressing when the segment has no DHCP server, or your PLC/devices are configured to reach the gateway at a fixed address.

The Ethernet subnet must differ from the Wi-Fi LAN's subnet. If both interfaces sit on the same range (e.g. both 192.168.1.x), routing between them is ambiguous and the gateway may send traffic out the wrong interface. Give the PLC segment its own range (e.g. 192.168.10.x) that doesn't overlap your office/home Wi-Fi.

Changing the network configuration reboots the gateway — it re-initializes the Ethernet interface with the new settings. Applying it while the gateway is mid-update is blocked; wait for that to finish, or use the "apply anyway" override if you're sure.

Parent/child uplinks

For larger sites, a gateway can have a parent gateway — it forwards through the parent rather than connecting on its own. The top gateway (with no parent) holds the internet uplink; children rely on it.

Use this when only one node has connectivity (e.g. a cellular uplink) but you need several collection points across a site.