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Connecting to MQTT event hubs with a ZLAN8309 Gateway RS485

ChrisScanlon 0 Reputation points
2025-04-28T02:03:56.94+00:00

Hi, wondering if anyone has had experience with connecting a ZLAN8309 gateway that polls RS485 to event hubs MQTT. The device can connect to unsecure and secure ports locally but appears to have a problem with certificates and connection directly into MQTT on AZURE. The ZLAN8309 works with other cloud services but has not been tested on AZURE due to restrictions in China to AZURE. It does work with AWS and Chinese cloud services. Any ideas, thoughts or guidance appreciated. I have an events hub instance and MQTT. https://www.zlmcu.com/products_ZLAN8309.htm gives product details. Alternatively can anyone recommend a 4G LTE Gateway with RS485 and ethernet port for TCP polling for a relatively low price that connects to AZURE. Thanks in advance. Being relatively new to AZURE, should I be pushing all traffic through IOT Hub first as opposed to event hubs MQTT directly? Certificates are loaded into both the MQTT certificate section and the gateway. I have spent many days full time on this to date and struggling to get a solution working. Yep, a little desperate and tired of the difficulties connecting and understandably looking forward to getting a connection through to AZURE and all the good things once data is in. Thanks :-)

Azure Event Hubs
Azure Event Hubs
An Azure real-time data ingestion service.
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  1. Alex Burlachenko 4,550 Reputation points
    2025-04-28T06:55:31.1766667+00:00

    Dear Chris,

    Connecting the ZLAN8309 to Azure Event Hubs MQTT can be challenging due to certificate and regional restrictions. Here are some official Microsoft resources that may help:

    IoT Hub vs. Event Hubs (Recommended for device connectivity)

    If the ZLAN8309 still doesn’t work, consider an Azure-certified gateway like Siemens IOT2050 or Moxa UC-3100. Let me know if you need further assistance!

    Best regards,

    Alex

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  2. Sander van de Velde | MVP 36,146 Reputation points MVP
    2025-04-28T15:53:55.1466667+00:00

    Hello @ChrisScanlon ,

    welcome to this moderated Azure community forum.

    I'm not familiar with this specific device and the product information and product specification does not mention Azure integration.

    I recommend contacting the manufacturer for detailed information and guidance on how to set up a MQTT broker connection with TLS and x509 certificates as authentication method.

    Notice that the Azure IoT Hub does not provide generic access over MQTT, you need to follow strict guidelines when connecting over MQTT only. See this post about how to set up an MQTT connection to the IoT Hub.

    If your device does not provide an interface to set up the Azure IoT Hub connection, this service is probably out of reach for your device.

    Microsoft Azure offers a 'vanilla' MQTT broker too, part of the Azure Event Grid Namespace MQTT support.

    Check out this post for several ways to connect to that MQTT broker.

    Notice that you need to provide to provide certificates for both TLS and x509 authentication.

    Please try this out first with a demo application so you understand the settings needed to have a MQTT client connected, first.

    If the response helped, do "Accept Answer". If it doesn't work, please let us know the progress. All community members with similar issues will benefit by doing so. Your contribution is highly appreciated.

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