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Node-RED

How to enable Node-RED on Cerbo GX

From changing the GX software to Venus OS Large to opening the editor for the first time — and what is worth setting up immediately: password, flow backups and spare space. According to Victron’s “Venus OS Large image: Signal K and Node-RED” manual.

What you need

  • GX device with Venus OS Large — Cerbo GX, Cerbo-S GX, Ekrano GX, Venus GX, Octo GX, MultiPlus-II GX or EasySolar-II GX. Color Control GX and CanVU GX do not support Venus OS Large. Speed comparison: requirements on the section homepage.
  • Internet on the GX — to download Venus OS Large from the update menu and to install additional nodes.
  • Computer on the same network — the Node-RED editor opens in a browser.

Preparation: Cerbo GX, MultiPlus-II GX and EasySolar-II GX do not require any. On Venus GX you must first install and run version v2.73 or later, and only then Venus OS Large — this is about the flash memory partitioning required by Venus OS Large.

Installing Venus OS Large

  1. Update. Update the GX to the latest version: Settings → General → Firmware → Online updates (in earlier versions Settings → Firmware → Online updates).
  2. “Large” image type. In the same menu, set Image type to “Large”, go back one level, check for a new version and install it. Download time depends on the connection, then the GX restarts, and the installation itself usually takes about 2 minutes.
  3. Check. After the restart, Venus OS Large settings should be visible in the Settings menu, under integrations — that means the image installed correctly.
  4. Enable Node-RED. Enable Node-RED in the integration settings. Installer access level is needed to enable and disable Node-RED and Signal K.

Updates continue to work the same — online or offline. The Image type setting determines which image is updated.

First opening of the editor

  • Address: https://venus.local:1881. If it does not work, replace venus.local with the GX device IP address on the local network, for example https://192.168.178.224:1881. How to find the IP address is described in the Remote Console on the LAN section in the GX device manual.
  • Browser warning — Node-RED on the GX uses an encrypted connection with a self-signed certificate, so the browser will report “your connection is not private”. Click “Advanced” or “Details” and continue. Benefit: the login and password do not travel across the network in plain text.
  • Old http address and port 1880 — after switching to https, the address must start with https and the port is 1881. Trying to connect the old way ends with ERR_EMPTY_RESPONSE. Additional listening on port 1880 (for nodes that connect only over http) is enabled in the user settings file — see dashboard and best practices.
  • Via VRM — the editor is also available remotely, in the Venus OS Large menu in the VRM portal. Depending on connection quality, it may be slow.

Editor password

Venus OS versionWhat protects Node-RED
v3.50 and laterThe security profile password (Settings → General → Security Profile) — the same one set for the “weak” or “secured” profile. Username: admin.
earlier than v3.50The Remote Console password, if set. Username: admin.

Safe mode and restart

In the GX menu you can enable Node-RED in safe mode: Node-RED starts, but does not run flows. You can then open the editor and fix the flow before anything starts running — flows only start after you deploy the changes. This is an emergency option when a flow is causing heavy GX CPU load or other problems.

Restarting Node-RED is done by turning it off and on again in the Venus OS Large Features → Node-RED menu.

Flow backups

  • Export: editor menu → Export → “all flows” saves the flows.json file on your computer. The manual recommends doing this regularly, and making an extra copy always before a GX software update.
  • Restore: on a new installation — Import that same file. If a flow uses nodes that are not in the palette, the editor will report it; you need to install them first.
  • What export does not include: the Node-RED configuration itself — that is in the .config.*.json files in the /data/home/nodered/.node-red/ directory.
  • Full data partition backup and reset: the file venus-data-00-backup-data-partition.tgz on the USB drive copies the entire /data partition to the USB drive, and venus-data-20-node-red-reset.tgz deletes the files from /data/home/nodered/ and lets you start Node-RED from scratch. Insert the USB drive into the GX and restart the device; completion is signalled by three beeps (on the MultiPlus-II GX, a message on the display).

Space on the data partition

Additional nodes are installed on the GX data partition, so they remain after a Venus OS update. At least 30 MB of free space must always remain on this partition. When free space drops below 5%, the GX shows warning #46 Data partition full; the exact value is shown in Settings → General → Modifications. If the partition is full, Node-RED may not start at all, and Venus OS stops working correctly.

The Victron node palette is part of Venus OS Large and updates only together with it. If a newer palette is already available online, but not yet in Venus OS Large, the instructions recommend waiting — a new Venus OS Large usually appears shortly after the palette update. What the palette includes: Victron nodes. First working flow: relay based on battery state.

No Victron support

Victron does not provide support for installations that use Node-RED for advanced solutions. Help: Victron Community, the “Modifications” area, Node-RED tag.

Devices this applies to

Sources

Content checked against Victron Energy documentation (datasheets and manuals) — as of 22 September 2026. Report a content error · Revision log