TM172 Open API to PLC Communication

[MSPARK]

Hello,

I have a question regarding the TM172 and API integration.
I would like to retrieve data from an open API
(https://api.open-meteo.com/v1/forecast?latitude=37.57&longitude=126.98&current_weather=true)
and bring it into a PLC.

I have used Python to read the data and convert it to Modbus, and I have confirmed that the data is valid
(please refer to the attached image).

Currently, I am testing using the TM172SIP/G, but I am experiencing some difficulties, so I would like to ask for your assistance. 

[ismailozinan]

Hello,

Since TM172 operates as a Modbus slave device, it is technically possible to write values obtained from an external API directly to the TM172 PLC using Modbus communication. For applications where secure data exchange is required, the use of TM172SIx is recommended. That said, this operation can also be implemented without TM172SIx, using TM172 alone.

From a technical perspective, your question does not appear to be directly related to the TM172 hardware itself, but rather to the Python application used to retrieve data from an external API. The code snippet you shared resembles a Modbus communication routine, not an API-specific implementation.

To retrieve data from an API, you must first have an active API subscription and valid access credentials. Once the data is received in your Python application, it can be converted to a decimal integer format and written to the TM172 PLC using Modbus, as shown in the example code we shared.

For security reasons, our own API key has been removed from the example. You should insert your own API credentials into the provided code in order to transmit the data to the TM172 PLC.

Best regards,

[FedericoM]

Hello,

if I well understood, you are trying to read this data using SIG.

Have a look to the attached ppt and sample projects.

[Bastian_Schmitz · Accepted solution]

If you want to do it directly with TM17SI, you have to wait till HTTP Get is included. The feature is on the roadmap. I Wait also for this function for exactly the same usecase like you. The get weather data to adjust as example outlet temperatures predictive. In the past i try something with a Nodered on a IPC in betweend which read the data, and push the data to TM172 via Modbus TCP.

[MSPARK]

Thank you for your reply.
Do you happen to know if there is an estimated release date for this feature?

[MSPARK]

It seems my explanation was not detailed enough.
Thank you very much for your kind response.

[MSPARK]

Thank you for your kind response and the sample materials.
I will refer to them for our future projects.

[FedericoM]

Hello,

HTTP Get is expected with ESME HVAC 1.10 in the first half of 2026