A SwitchDin Droplet communicates with on-site devices — most commonly inverters, batteries, meters, and controllable loads — to collect telemetry data and send control commands.
For this to work, the Droplet needs two things: a supported communication protocol and a driver for the specific device. The way the Droplet connects to a device depends on what is available at the site.
Connection methods
1. Direct wired connection (recommended for Droplet PLUS)
The most reliable way to connect devices to a Droplet PLUS is through a direct wired connection. This avoids any dependency on the local site network. Depending on the device brand and model, two options are available:
- Ethernet (TCP) — connect the device to one of the Droplet's Ethernet ports using a CAT6 cable. This is the preferred method for devices that support Modbus TCP or other TCP-based protocols.
- RS485 (Serial) — connect the device to one of the Droplet's USB ports using an RS485-to-USB adapter. This is common for devices that use Modbus RTU. The Droplet PLUS supports multiple RS485 connections.
2. Network connection (LAN)
If a device is already connected to the local site network, the Droplet can communicate with it over the LAN — provided both the device and the Droplet are on the same subnet.
- Droplet PLUS: connects to the LAN via Ethernet.
- Droplet ONE: can connect to the LAN via Ethernet or WiFi.
Some secured networks may require firewall rules to allow traffic between the Droplet and the device. See What ports and addresses must pass firewall for our Droplet on a secured network for details.
3. API connection
For some specific devices, such as Tesla batteries, the Droplet can retrieve data through a cloud API connection rather than a local wired or network link.
Connecting an inverter directly to the Droplet PLUS (without a LAN)
In cases where connecting both the Droplet PLUS and the inverter to the same local network is not feasible, the Droplet's Ethernet port can be reconfigured so that the inverter plugs directly into the Droplet via an Ethernet cable.
The Droplet PLUS has two Ethernet ports, making it well suited for this configuration — one port serves the inverter while the other maintains the internet connection.
Once configured, the Droplet acts as a small DHCP server on that port, allowing the inverter to obtain an IP address and communicate directly with the Droplet. The inverter should then be discovered in Stormcloud.
This reconfiguration is performed by SwitchDin. To request this, please submit a support request with the following information:
- Droplet ID
- Which Ethernet port you would like reconfigured (e.g. ETH0 or ETH1)
- The inverter brand and model that will be connected
- The communication protocol the inverter uses (e.g. Modbus TCP)
Our team will configure the Droplet remotely and confirm once it is ready.