PR55-21 MQTT does not receive sensor signals

We have just purchased the below listed units:

  • PR55-21 MQTT
  • PR55-20 A

Trying to setup the stuff as it is suggested in the documentations without success after many trials. Web interface does not show any received data. Alpha station says “Unable to communicate with the modem”.
There might be hardware or firmware issue with the unit(s). Please advice.

Go through these troubleshooting steps:

  1. Ensure antennas are connected to both the MQTT Gateway and the sensor.

  2. Connect a 12VDC power supply source to the MQTT Gateway(Assuming you have already configured for connection to your MQTT Broker).

  3. Open the lid of the sensor and flip the power switch inside towards the wall of the enclosure to turn it on.

  4. Check to see if any data was received on the MQTT Broker after 10 seconds or so.

If this does not work please provide the following:

  1. Top down photo of the MQTT Gateway with the lid removed and powered on.
  2. Top down photo of the sensor with the lid removed with the power switch in the On position.
  3. Screen shot of settings stored into the MQTT Gateway.

Thank you,
Travis Elliott

Dear Travis,

I went through the suggested steps, but no success. We have another gateway, a PR55-21 AWS, that receives the sensor data and displays properly on the web inteface.

I am sending the requested photos:



So to troubleshoot receiving of data from the sensors are you subscribing to a topic on the MQTT Broker? Does the MQTT Gateway LED turn green indicating it has a valid connection to the MQTT Broker?

No, the MQTT gateway LED does not turn green. Should it receive sensor data without an active MQTT connection? It’d seem logical. The AWS Gateway displays each received message in real-time.

The attached video shows that the LED is blinking blue.

Enter your MQTT Client credentials and WiFi Network credentials and save them to the Gateway. Allow it to connect to the MQTT Broker(Green LED), then subscribe to the MQTT Broker Topic ‘#’ with your MQTT Client software, then power up the sensor. Let me know if anything comes through.