Modbus TCP for CTA Heatpump

Configuration
1

I tried different ways but the result was not satisfactory. This is probably because I am a complete beginner when it has to do with Modbus. I hope you can help me in a fairly simple way.
I have received a table with all the important data from the manufacturer CTA. For example, the following settings should be used for the outside temperature:

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My configuration in HA:

modbus:
  - name: CTA
    type: tcp
    host: 192.168.178.23
    port: 502
    sensors:
      - name: CTA_Aussentemperatur
        address: 2000
        swap: byte
        data_type: int32
        slave: 1
        input_type: input

I do receive some data but the values are by fare not correct. The outside temperature is 8°C and the received values are 10747712, 7667520, 1075183424,…

2

I think I figured it out. It was just the “swap: word” instead of “swap: byte”

modbus:
  - name: CTA
    type: tcp
    host: 192.168.178.23
    port: 502
    sensors:
      - name: CTA_Aussentemperatur
        address: 2000
        data_type: float32
        swap: word
        slave: 1
        input_type: input
3

Hello,

I also own a CTA heat pump, Aeroheat 18A with Wandregler 2.0. Where did you get the datasheet for the TCP Modbus data?

Thanks!

4

Hello Tudor T,

I’ve got the datasheet directly from the technical customer service by CTA. They’re very friendly and you just have to commit that you don’t publish it.

5

What hardware do you need to connect the HA to the CTA via modbus?
I currently have HA on a RPi and am now investigating how I can integrate my CTA heatpump. As I also am registered on the heatpump24 portal, this might be another option, but I guess modbus would be easier…

6

On the heatpump side: Did you need to set additional parameters? I can reach my CTA heatpump via the browser accessing the inbuilt web server. But I do not receive an answer via modbus so far.

7

I do not think any additional hardware is necessary: Your HA will communicate via TCP with the heatpump. Did you try to reach it via the web browser? You can just type in the IP address and it should open a login dialog. The default passcode is 999999.

8

I had already connected the heatpump with my router (normal LAN-Cable). In your router configuration you will find the correct IP-Adress. It should work with the modbus integration and the above mentioned configuration.

1 Like
9

Asked CTA to provide me the table for my heatpump model and will then test.

10

it asks for user and password (advanced settings installer or advanced settings admin (oem), what do you enter as user if password is 99…9?

11

Merci, thanks for supplying you config, it works for me. As I have a CTA with TWW, I would like to add the address(es) for ‘used energy TWW’, do you know which address that is hidden? (an d can post it to here or to me)?.
I had two calls with support and marketing CTA and they do not give me the modbus interface definition. This is ‘company owner decision not to give that out’. I buy a expensive device and do not get the info to use it 100%, what a shame. Shame on them.

12

Yes, I know. That makes it very difficult for us. Here are the the TWW addresses:
Input Register:
2010: TWW Temperatur in °C
2012: TWW Ladefßhler °C
2022: TWW Temperatur unten in °C