Domoticz and the Vents VUT R 600 VE EC A21 recuperator: communication via Modbus and Raspberry Pi

Question

Hello I have a Vents VUT R 600 VE EC A21 recuperator Domoticz set up on a Raspberry. I would like to communicate the domoticz with the recuperator. For this I bought: I connected in parallel to the A+ B- and GND to the keypad. How do I now handle this programmatically so that domoticz can see...

zuhjk · Accepted Answer

I want to read the temperature and humidity sensors integrated into the rs 485 using domoticz. I buy these sensors on Ali.... To start with, I have mastered the readings with a PC+ USB/RS485 converter. You have to learn the specifics of the RS485 standard. It is not like the RS232. The frame has a proper structure
and contains in it a read or write command. This can be done using a PC. The
PC is the master and the rest are slaves. The slaves have their addresses in the frame, theoretically there can be 254 (I omit the FF address) but so up to 32 without any problem. The manufacturer has probably limited them to 16 devices which seems reasonable. Knowing the default address, you can read data from the device. You are unlikely to write to rs. Integration with domoticz is another matter. You can use USB and you can also use
the RS485/ETHERNET converter.
First of all, it is necessary to run the readings via a PC,

starob · Accepted Answer

The BMS functions cat is Modbus TCP, so you probably don't even need a converter. You need to get the modbus protocol specification (register addresses). You can also tentatively try to read with some tool directly over the network from Windows on port 502. e.g. ...edit from the search on the official manufacturer's website. There is a base from which you can start the tests.

starob · Accepted Answer

Basically it's about nothing in the document linked earlier is everything. 1. If you already have any control device connected after RS485, you are only left with WiFi or Eth. 2. To start - as @zuhjk wrote - fire it up on your PC, Download the subliked MasterSimulator. and configure in it the ModusTCP connection Ip:recuperator port:502 3. Now you can try to read the InputRegister from address 0. If you manage to read something meaningful and compatible with this table - you can try to integrate it with Domoticz.

zuhjk · Accepted Answer

These plugins are working and not working. I tested one of them but it didn't work. Then someone wrote that there was a bug and the author fixed it. Generally
to make domoticz read you need to know the principle of how it reads them. Node red is a flow-based programming language. It concatenates data from rs485 with commands understood by domoticz. It also generates queries over rs485 according to rtu standards.
Then you can also collect data from any devices. I have, for example: in domoticz, the signal strength from the mikrotik router, the temperature from the thermocouple after rs 485, and you can measure the temperature of the flue gas from the boiler. Another thing with MQTT. The gateway I have allows rs485 rtu to be converted to mqtt. If I can manage in json to add commands to domoticz on it, then all I need is it and the mqtt broker to make domoticz suck data. But that's in the queue waiting to be investigated.

xury · Answer

There is no word in the DTRka or other files about the modbus protocol. If you find it somewhere, let us know.

Daro1003 · Answer

In the product card file there is some information that only this air handling unit has Modbus communication. When I bought the AHU about 1,5 years ago the Vents technical department assured me that Modbus communication is in this AHU.

What information exactly do you need ? I will send an e-mail to the technical department of Vents and maybe they will say something more, just what to ask ?

Product card:

Daro1003 · Answer

If the recuperator is connected via Wi-Fi to the home network, I can already read something on the PC ? Is it to be connected differently or do I connect to A and B of the recuperator and to the LAN via some converter ?

starob · Answer

It seems that this magic A21 module is such a window to the world and it is the one that has the modbus built in. I don't know enough about the Vents philosophy to answer anything specific (I don't know at all) Enclose some papers for the devices you have then maybe something will become clear.

Daro1003 · Answer

Ok I am attaching everything I have. But please write colleagues what to ask at vents for what data exactly. I will send them an email on this to the technical department. It seems to me that this A21 only embedded on the motherboard and other controllers plugged into the board work on this. Can you drop a link to such a sensor ?

Daro1003 · Answer

Yes I have connected such a keypad with data as shown on the screen: So if there is one keypad then nothing else will work ?? How to connect to a computer via e.g. Wi-Fi remotely via LAN through an IP address ? Here is the problem because I do not know the IP address of the recuperator connected via Wi-Fi gets some from the pool, I can not find it anywhere, neither on the router nor with a network scanner I can not find out which IP address it is, but this is rather a bad solution because after restarting the power supply it already gets a different address and it will not work. On the other hand, when connecting via ETH I can set a fixed IP address in the options, so I have to start with a cable connection and setting a fixed IP further on: Thanks colleagues for your help until then I will work.

starob · Answer

Try to It must be saved somewhere in the router! In addition there will be somewhere an option p.t. about Mac filter, which allows by mac address to assign a fixed IP. If there is not then it is time to change the router Beyond that probably here changes the address type StaticDHCP .

Daro1003 · Answer

It is at this point that a fixed IP is set, but a wired connection I tried this and after saving the settings returns itself to DHCP if I do not have a LAN connected but Wi-Fi but LAN is not a problem. Is this how a configured connection should look like: Something should show up in the table ? Any data ? It looks like something is flying: .

Daro1003 · Answer

And if colleagues manage to come up with something

starob · Answer

What more does the colleague expect? ...From the test it appears that you can connect and read the registers correctly. Now do the same in domoticz via modbus (as its documentation says). [

Daro1003 · Answer

I just don't know how to set this up in domoticz and whether I have the right plugins. When I try to add and change the settings, domoticz crashes for a few minutes and I also can not remove the added plugins: I don't know if both READ and WRITE are to be added or just one of them and option settings:

starob · Answer

You have to decide what you are trasmitting over (what converter you are using).

Till now it was mentioned about the LAN converter, so you set as in the program RTU over TCP. Then you don't define serial - because it is defined in the converter.

If you use USB then you set only RTU and omit TCP settings.
If you only read then READ, if read write then READ and WRITE.

These are universal rules, I don't remember the details of domoticz itself.

Daro1003 · Answer

Yes after the LAN.
Reading as much as possible mainly the temperature of the air vents, because what else can be read unless the options are also available.
Recording also fits as if from Domoticz e.g. would like to change something in the air vents.

I wonder if this is possible at all.

starob · Answer

It can be done... because from your picture (from radio) you can see the input registers read some temperatures at the level of 19.9C.
First of all focus on getting the readings in domoticz from one register.

Comunication mode: RTU over TCP
Modbus Function: Read Input register

This must be the same parameters as in the radio program.... remember that other programs communicating via modbus should be switched off while domoticz is running

.edit ..just what protocol did you get these readings in radio?!
Because the documentation says it should be Modbus TCP and your pictures suggest Modbos RTU over TCP.

zuhjk · Answer

A colleague got confused between rs485 transmission over lan and modbas rtu. This is due to lack of knowledge about this protocol. But he is on the right track.

zuhjk · Answer

And how are your readings in domoticz?

Daro1003 · Answer

The topic lies lack of knowledge. I don't know if I have the right plugins for this and if they are set up properly.

zuhjk · Answer

I guess you have to hire a more savvy one then the subject will move on.

Daro1003 · Answer

What do you mean ? I can figure it out myself but I can't do without the help of other domoticz users because with every domoticz update there are some circuses and something doesn't work. If someone does it for me it will probably work until.

Daro1003 · Answer

Hey mate @zuhjk are you able to help configure this connection ?

zuhjk · Answer

No looks like maybe I can. There are several methods. Swap rtu and publish MQTT to any broker. I domoticz on a dell terminal, debian, I have a broker there too. I hired a specialist what in node red glued the frames together and integrated with domoticz. Generally there are specialists everywhere but no one will help. I am now testing wireless temperature and humidity sensors ela bluetooh. Such a thing only I still have humidity. I have the readings in domoticz. I collect data using teltonik's rutx10.

Daro1003 · Answer

So it won't be that simple if NodeRed comes into play, which I've read something about but have no idea what or how.

Daro1003 · Answer

That is, what is necessary to delve into NodeRed I see.
Are there any instructions on how to get started ? How to install get up and running ? You have to start somewhere.

I currently have a Sofar photovoltaic inverter which also has RS485 communication for the computer and this could be used cool I see, for this recuperator and also Vailant EcoTEC also probably has RS485.

How do you suggest how to get started?

zuhjk · Answer

Collect some money and ask a person who knows these topics. I have advertised on smart home and here and it sucks. All the smart people and the topic
lies and withers. Maybe soon I will be able to sell this gateway with node red embedded. To write in node red, it is best to know java script.
Now the topic is being embraced.

From blutocz to MQTT and to domoticz

.

Daro1003 · Answer

Can you recommend someone who could take care of this for me?

The only downside to outsourcing everything is that I want to add something and then have to outsource again.

Are you already working with this yourself or are you outsourcing ? All in all, I would have a recuperator, and a sofar inverter, maybe a Vailant if possible, and that's it.

Domoticz and the Vents VUT R 600 VE EC A21 recuperator: communication via Modbus and Raspberry Pi

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