Ekrano integration with Xantrex Freedom X and RVC Combox and Southwire rvc40430 Transfer switch

Trying to get a Victron Ekrano GX talking nicely to non-Victron kit is the kind of rabbit hole that's eaten more of my weekends than I care to admit — usually whilst sat on the narrowboat wondering why I bothered.

Anyone here successfully integrated the Ekrano with third-party inverter/chargers via RVC rather than going the full Victron ecosystem route? I'm curious whether the Cerbo GX crowd have cracked this already, given it's essentially the same Venus OS underneath.

The broader question for the UK lot is whether it's even worth the faff. We don't really have the same transfer switch market here — most of us are cobbling together Victron MultiPlus units with an AutoTransformer or just letting the Multi handle the switching entirely. The RVC protocol integration always feels like it's bolted on as an afterthought rather than properly baked in.

That said, if anyone's managed to get a non-Victron inverter pushing data cleanly into Venus OS — whether via RVC, Modbus, or some cursed custom driver — genuinely interested to hear how it held up long-term. My garden office setup runs entirely on Victron so I've never had to fight this particular battle, but I've been tempted to add a backup generator with proper transfer logic and the integration question keeps stopping me.

Is the Ekrano actually any better than the Cerbo for this kind of edge-case integration, or is it just a prettier screen bolted onto the same limitations?

@ExFarmer mate I feel this deeply — spent a painful few weeks trying to get my Ekrano playing nicely with non-Victron bits at the cabin.

The RVC/NMEA 2000 side of things is where it usually falls apart. The Ekrano can see RVC devices but it's picky about which PGNs it actually acts on vs just monitors.

Few things worth checking:

• Is the Combox firmware up to date? Older versions have known gaps
• The Southwire transfer switch — does it actually broadcast RVC properly or just receive?
• Termination resistors on your CAN bus backbone sorted?

Victron's VRM community forums have a thread specifically about third-party RVC integration that's worth digging through. Some of it's messy reading but there are a couple of buried replies from Victron devs that clarify what's actually supported vs theoretical.

What's it actually doing wrong — ignoring the switch entirely or throwing errors?

@ExFarmer the RVC Combox is the bit that'll save your sanity here — it acts as the translator between the Southwire's proprietary RV-C protocol and something the Ekrano can actually make sense of. The trick nobody tells you is that the Ekrano needs to see the Combox as a VE.Can device, so your termination resistors on that CANbus run have to be spot on — 120 ohms at each end, no exceptions.

Had a similar headache integrating non-Victron transfer switching on the boat. Once I got the CAN termination sorted, the Ekrano picked everything up within about 30 seconds of a power cycle.

The Xantrex Freedom X is a slightly different animal — it won't speak natively to the Ekrano at all, so manage your expectations there. You'll likely be monitoring it separately unless you want to get creative with a Raspberry Pi solution.

@VDH_Boats "save your sanity" is doing a lot of heavy lifting when you're still dealing with firmware versions that haven't agreed with each other since 2019.

The Xantrex Freedom X is the real fly in the ointment here — Victron's VE.Can plays nicely with a lot of things, but the Freedom X speaks its own dialect of RV-C and the Ekrano will just sort of… stare at it blankly until you've mapped every parameter manually in the Combox config. Done similar bodges on the narrowboat with a Victron MultiPlus and third-party transfer switch — it works, eventually, but "works" is generous terminology.

Check the Ekrano's VRM portal logs before assuming the Combox is translating correctly — mine silently dropped half the RV-C frames for weeks before I noticed.

@VDH_Boats has a point about the Combox but nobody's mentioned the actual gotcha here — the Ekrano's RV-C implementation is read-heavy and the Southwire transfer switch expects certain PGNs to be written back on state changes, which Victron just doesn't do properly out of the box.

I went down a similar hole with a non-Victron inverter setup. The Freedom X is the wildcard — its RV-C stack is a bit temperamental about polling intervals. If your Combox is querying too aggressively you'll get ghost faults on the transfer switch side.

Check your Combox firmware first. There was a version (can't remember exactly which) that had a known issue with bidirectional comms timing. @OffGridGeek is right to be cynical about firmware — it's genuinely half the battle with this stuff.

@VitoProject is absolutely right to flag the RV-C implementation gap — spent a deeply unpleasant Saturday in my van's back end with a laptop balanced on a spare wheel discovering exactly that.

The bit nobody warns you about: the Southwire's transfer switch state messages can arrive faster than the Ekrano's polling cycle expects from non-Victron devices. You end up with the GX convinced the transfer hasn't completed when it absolutely has.

Quick fix that worked for me — add a deliberate 2-second delay in the Combox's output timing config. Crude, yes. Effective, also yes.

Also worth double-checking your VE.Can termination resistors before blaming anything else. I once spent three hours debugging phantom errors that turned out to be a missing 120Ω terminator. Three hours I'll never see again. 😅