Hi, new to home assistant, but lucky enouth that almos all my smart existance devices were easily integrated (despite not being a criteria when aquired);
Irony is that now, I am about to comit a cardinal sin and buy an equipment that has no integration: a ventilation unit from Meltem;
They can be cotrol by remote and recently have an app that is connected with the machine throw a gateway device that connects to my network so I see some perspective for future integration; Quick and dirty soution whould be to monitor the power and mapped the remote control;
Besides the mentioned gateway they also offer a model that can comunicate via MODBUS to a wired control unit (that I don't have) or via another cable option to a property wired small keybord; the question is can this wired connections could some how be intercepted and used for a future integration with home assistant or there is no point in getting them?
Thank you!
I started with Home Assistant about one year ago, not to integrate anything smart for the house, but really to be able to connect to my Solar PV inverter and battery.
I have a Solis Hybrid inverter, and Pylontech batteries. Both very good and popular, but both are considerably challenging to connect to. There are several âintegrationsâ of various means that can be added to HA, but all suffer in one way or another as the manufactures do not provide much in the way of open access.
To reliably get to my inverter I have gone down the Modbus route. The cloud website / API calls / data logging stick approaches do work, and there are several integrations, but nothing that is rock solid reliable and/or does quite what I want.
Modbus is an industry standard, and should be very easy to use, however it can be quite tricky. Success requires both hardware and software, and a lot of configuration, and as we say in the UK, you need to get all your ducks lined up.
Your ducks are likely to be:
The device connectivity - accessing the Modbus interface board
The device registers
The device RS485 (Modbus RTU) settings
Getting an adaptor to connect to HA
Getting HA to run Modbus connection correctly.
In my situation, I use Node-RED (HA addon) to do all the Modbus connectivity using Modbus TCP. I find this reliable, easy to prototype / debug.
I use a (semi) industrial Ethernet to RS485 adaptor (which is Modbus aware) at the inverter end, with ethernet from the house network to the adaptor
I have a short cable from the adaptor to the inverter RS485 Modbus comms port.
I have looked quickly online for âMeltemâ and found a manual, which is quite specific about the Modbus interface board, the registers, and settings required. For myself I would feel confident enough to try connecting to the device and âhaving a goâ.
The kind of things to keep in mind (and this is not an exhaustive list) are:
You can only have one master on a Modbus bus. If you already have anything else (interface, hub, controller) that is physically connected to the unit and is driving the Modbus, then adding another to/from HA will (almost certainly) be problematic, particularly for register writes. This almost certainly rules out having both HA access and one of the manufacturers controllers or bus converters (as they appear to connect via Modbus). I would first want to know if I bought another controller, does it use the Modbus board?
You will need an adaptor somewhere to connect from the serial (RS485) to HA. This can be a cheap USB interface, or it can be serial to ethernet. Not all adaptors work, and there are issues with conversion. Whilst an adaptor can, for example, converter TPC ethernet to RS485 serial, Modbus TCP needs to be modified to Modbus RTU by making changes to the data packets, and some adaptors are only âModbus ableâ and not fully âModbus awareâ.
So, to try and answer your specific question.
From what I have read in the manual, with the Modbus board available (and nothing else using it) in the ventilator unit, you should be able to connect to the unit from HA using Modbus.
The âMeltemâ ventilator register map shows quite a number of interesting sensor values, and a few control registers too.
Please note, I say âshouldâ.
there are a few things to consider when talking about modbus.
- There is Modbus RTU and Modbus TCP
Modbus RTU is usually a connection that requires additional Hardware, for example an RS485 to USB converter (can be plugged in directly to your HomeAssistant, if possible) - or a ModbusRTU to ModbusTCP converter, which can then be connected directly into your Network.
There are probably other solutions, such as the mentioed âESP32â InterfaceâŚ
In both cases - Modbus RTU and Modbus TCP you need to have a documentation about the Addresses and parameters used.
Also, it needs to be considered, that in most cases - modbus does only allow a single connection being active.
This means, if you connect your HomeAssistant to the Modbus Device, you probably canât connect another device to it - at least, not at the same time.
But for the last, there are also Solutions available such as Modbus Proxy⌠they do allow to connect different devices to the same Modbus Interface.
Wow, thank you for such a detailed answer; You were correct to assume that the bord might be used for multiple purposes, I just receive the information that the modbus option would exclude any other form of control except some on unit buttons; So I will have to weight pro / cons for each option
Thaks for the info
They do offer a RS485 to USB converter made by the same producer
Just wanted to add that I achieved the WRG II integration via modbus using the Meltem Gateway. Details can be found here: Meltem WRG II integration via Meltem Gateway and Modbus