rs485 Image


trouble with ET340 connection by new Zigbee 485(DRF2659c), USB (DRF2658c) module

Hi there,

please, let me ask for help if possible with the new zigbee RS485 (DRF2659C) and USB(DRF2658C) module that I would like to use for wireless connection of ET340 to Venus OS.

I have trouble with them to be recognized be Venus OS (2.73 and 2.80). I find out that zigbee modules come with quite new firmware v8.5 and it has ID_MODEL=USB_Serial, that I have adjusted in "serial-starter.rules", in "" and I have played around also with serial-starter.conf. Without success till now.

When I do wired connection all works well and ET340 is recognized as device ID:345 with 2571291A number and is visible by Venus OS . See screenshot 1.

When I set it with zigbee, there is no info about find cgwacs device. See screenshot 2.

Any suggestion what I could try is welcome? Thank you.

Best Regards,


1. Wired connection


2. Zigbee connection


3. USB-zigbee module


hsaman asked
dimiwa commented ·

3 Answers

VenusOS, Modbus and compatible devices (Heatpump Ecodesign ED 180RF)

Hello everyone,

I am an enthusiastic VenusOS user managing 2x systems based on it. Currently the systems are fairly straightforward with solar panels, Lifepo4 batteries, MPPTs, and inverters.

Now I find myself in the need to add a heat pump (Ecodesign ED 180 RF) for hot water production and I was wondering about compatibility/interfaceability.

The manufacturer tells me it has Modbus interface and that it is compatible with all systems supporting this bus. In this case, the interface would allow to readout values and set thresholds.

My question is whether anyone knows if this is supported by VenusOS (via RS485-USB converter). Or actually whether in general hot water generating systems are supported and can be monitored within VenusOS. Off course, if this would be even accessible within Node-RED this would be the cherry on top ;-)

Thank you in advance for your inputs!


dgnoise asked
dgnoise answered ·

2 Answers

connection between Si-RS485 and CCGX


Trying to connect a Ingenieur buro Si-RS485 to VRM. Setting:

Si-RS485 ---- > 12V from 24 to 12V transformer and RS485 to USB cable 5m (VE bus Multiplus V 430) -------> USB 12m self regenerating -------> CCGX (V 2.91) -------> Modemrouter -----> 3 and 4G ----> Internet ----> VRM


No answer from VRM,

Impossible to use Modbus setting from a PC attached on same network


Not a specialist, just a self trained Victron's user


Any tip???

Lionel SEYDOUX asked

0 Answers

EM24 Rs485 vs. Ethernet

I‘ve heard that an ESS system with an EM24 RS485 is much slower in comparison with an EM24 Ethernet. I‘ve been told that the RS485 variant needs up to ten times longer for measuring and therefore the complete regulation of the system is quite slow. Is that right?

Henning Schewe asked
hardy-tuner answered ·

1 Answer

Availability of Isolated USB - RS485 transceiver


Due to the global issue of chip stocks, the Victron recommended "Hjelmslund Electronics USB to RS485 Iso converter" hasn't been available for a while.

Can anyone recommend another Isolated RS485 transceiver for a Multiplus II 48V/10000, is anyone using a RS485 repeater ?

My ET112 modbus meter will be 50 metres away at the supply and baud rate will be 9600.

Best regards


simat asked
simat answered ·

6 Answers

ET 112 not showing up on Cerbo - 15m away


After hrs of going round in circles, using the RS-485 to Cat6 Extention to the USB - RS485 adapter still nothing... Any help would be appreciated.

sales-1 asked

0 Answers

Energy Meter ET112 communication link

Like many before I have been challenged by installing an ET112 "grid meter" at mains AC entry point when my whole solar setup is in an outbuilding around 40m away. Hard wired communication back to a Multiplus 2 GX is just way too complicated, and would require laying underground conduit to hide cable runs across a large parking area. I did consider the Zigbee option, however, from my experience of trying to get a decent extended WiFi signal to my outbuilding I am not even sure the Zigbee would guarantee a solid connection (it is effectively a wireless mesh system operating on the same 2.4GHz as WiFi. At that frequency passing through 3x 25cm solid walls over the distance required is probably on the edge of operation?).

My thoughts turned to a RS485 radio link. At this stage I know I am subject to scrutiny and I make no guarantees that this would suit everybody's situation. If I could I would go for a hard-wired link... but I can't. I absolve myself from all liability if anyone decides to copy my project.

I have done some projects with LoRa in the UK so the available 868MHz band is well known to me. I stumbled across a RS485 transceiver board on ebay (....don't you just love it?), made by our friends in a different time zone. So, I purchased 2 of these boards to play around with. They use FSK modulation and make the board in 433/868 MHz versions (check your country rules!!). Ideally they run on 5v and the manufacturers claim a free air (line of sight) range of 500m. They appear to do what they claim.

The next part of the puzzle is the link to the GX device. Victron "recommend" FTDI UART chip based serial communication by implication (....that is what their standard connection cables seem to be based on?). There are 2 other UART chip devices in general circulation the CH340 and the CP2102(SiliconLabs). From what I have found the Victron equipment does not natively communicate with CH340 devices (you need the drivers installed). The CP2102 chip works with a Venus GX I have on a raspberry pi system and also with Multi 2 GX (which effectively has a Venus inside). I have not tested with Cerbo GX but there is no reason to assume it will be different since the software is all Linux based?

The USB to RS485 device I bought was the DSD Tech SH-U10. Which is a dongle that plugs into my raspberry pi. Be aware that this will not fit within the Multiplus 2 removeable protection panel over cable entry. You could just get a USB extender cable so that the dongle is outside or, as I am going to do, buy the DSD Tech SH-U10L which comes as a connection dongle on the end of a USB cable... much neater solution.

The transceiver uses less than 30mA at 5V so at the Victron end mine is powered off the DSD SH-U10. However, I have built small mains powered 5V DC power supplies into my devices so that I can run the radio link off a fused spur at my consumer unit end. In fact I used the opportunity at the grid entry point to install a Mains isolator between electricity board meter and house consumer unit in a small secondary consumer unit (designed for garages/outhouses etc). That also neatly houses the ET112 meter, since there was no space left in the main consumer unit.

So, that's it. I 3D printed some ABS boxes for neatness and to keep it housed safely. Although I only "need" the power supply at one end I have just printed the same box at both ends. I have played around with different cable options and have decided that standard internal BT telephone cable is a good option, it is just 2x twisted-pairs within the same cable. Of course this has not been tested to extreme but it has been soak tested for a week or so and appears to connect flawlessly?



gazza asked
gazza edited ·

0 Answers

Carlo Gavazzi EM111 feed-in feedback loop


I recently installed an EM111 Carlo Gavazzi meter to monitor my grid connection point to limit my grid feed-in.

To make the meter work, I had to change the meter parameter "Measure" to "b", such that reverse power flow would read as -ve and forward as +ve. When set up like this, the Victron system works perfectly.

However, after a couple days, I am finding this "Measure" parameter changes itself back to mode "a". When it does this, all power, even feeding-in to the grid, is labelled as a +ve power flow. The Victron sees energy being consumed, and then raises it's feedback to combat it. The system is actually feeding in this power, so this results in a positive feedback loop until the Victron maxes out.

Would Victron be resetting this parameter via the modbus RTU? I have seen no indication in the EM111's manuals that they would self-reset, so I am at a loss. Any help would be greatly appreciated!

My system is as follows:


Quattro 10KVa

EM111 connected to RS485-USB adaptor in CCGX

2x 150/45 BlueSolar MPPTs

400Ah 48v Lithium CANBus Battery Set.

andyandy26 asked

0 Answers

Double ET112 sur convertisseur ZIGBEE-RS485


j'utilise pour le moment un ET112 via 2 convertisseurs ZIGBEE-RS485 DRF2659C (dont 1 avec un convertisseur RS485-USB coté RPI+VenusOS) pour le comptage ENEDIS.

L'un d'entre vous a t'il déjà testé 2 ET112 en // sur un seul convertisseur ZIGBEE, en changeant les @ des ET112 comme avec un convertisseur RS485-USB ?

Ou faut il impérativement 1 convertisseur ZIGBEE par ET112 ?

krystof69 asked
Thierry Cortassa (Victron Energy Staff) answered ·

6 Answers

Very long RS485 cable for ET112


I have a question about my methodology for running a long RS485 cable, beyond 30 meters, especially in regards to the USB-RS485 adapter and the wiring for the 120 Ohm termination resistors either end.

I have read through the available documentation from Victron and FTDI and I have arrived at what I *believe* is the correct method I should be using.

Can someone please confirm that my understanding of this is correct based on my attached picture.


In case any questions come up in regards to moving the Multiplus/MPPT/Cerbo/Batteries closer, please note I do not have the space to do this. I can only feasibly extend the AC-in side to my main consumer unit and extend the RS485 connected ET112 data back to the DC installation 35 meters away.


jc2010 asked
matt1309 commented ·

11 Answers

USB to RS485 interface extension cable

Since the usb to rs485 intereface comes in either 1.8m or 5m what is the recommended way of extending this to another 20m? Would a cat 6 cable be suitable for instance?

Cliff Raccani asked
mk1 commented ·

2 Answers

Intergration Of Victron Cerbo and Solaredge Meter

Intergration Of Victron Cerbo and Solaredge Meter

SE meter operates on RS485

Ebrahim Railoun asked

0 Answers

How to connect ET340 to Venus via ETHERNET ?

I am stuck with my ET340 setup .
ET340 is sitting in the power distribution cabinet (solid steel case - forget WIFI ).
The pipes, laid in concrete, I had forseeen for additional wires, have been wrecked by the builders - squeezed...
So I end up having no option to -route an additional wire to my Venus/ Multigrid, two rooms away.

I do have Ethernet LAN in the cabinet and I am aware of RS485 <-> Ethernet adapters, but will the Venus / Multigrid be able to communicate ?

vicky asked
turbyho answered ·

9 Answers

Venus GX not detecting ET112 via RS485 but can see it on laptop


I have a Venus GX and trying to use a ET112 via a RS485 cable when I plug it into a laptop that RS485 cable lights up and I can see the ET112, but when I plug the USB into the Venus GX I get nothing on the meters section and the RS 485 cable does not light up.

Should the RS485 cable light up when plugged into Venus GX device ?

Do I have to switch the RX\TX cables around between using it on a laptop to the Venus GX ?

Any help would be great.


techguru asked
daba answered ·

2 Answers

ET112 to Cerbo 50 rs485

Hi. Is it possible to connect ET112 to Cerbo with 50 metre rs485 to usb cable

darrencham asked
sanchuka commented ·

5 Answers


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