FMC920 + OpenRemote MQTT Integration — Certificate Chain, FMC003 Default Config & Model Mapping Questions

Application best practices
1

Hi everyone,

I’ve just integrated my Teltonika FMC920 device with an OpenRemote server over MQTT. I followed the official tutorial:

I have a few questions that I hope someone can clarify:

1. Certificate chain (fullchain.pem)
The certificate located at /deployment/letsencrypt/live/{OR_HOSTNAME}/fullchain.pem contains only two certificates:

-----BEGIN CERTIFICATE-----
CERT 1
-----END CERTIFICATE-----
-----BEGIN CERTIFICATE-----
CERT 2
-----END CERTIFICATE-----

According to the tutorial, there should be three certificates, but I haven’t modified their order or contents — I uploaded it exactly as generated.

Communication with OpenRemote works correctly.
Is this something to worry about, or is it safe to leave it as it is?

2. Default FMC003 configuration
After installing OpenRemote, there is a default configuration available for the FMC003 device.

I remember that when I removed it, it caused significant issues in the system.
Why does deleting this default configuration lead to problems?

3. Using a different device (FMC920)
What is the correct approach when using a device other than FMC003?

  • Should I create a new Teltonika Model Configuration Asset for FMC920?
  • What should I do if my FMC920 appears in the system as an FMC003 device (the Model Number field in the Car Asset shows FMC003 for IMEI xxxxxxxxxxxxxx)?

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What with Deafult model number here?

4. Admin password management
Is it possible to change the Admin user password at any time?

I see that it is initially set via an environment variable in the .env file.
Should I change it there, or is it safe (and recommended) to change it directly from the OpenRemote UI/panel?

2

Good morning @Maciek ,

  1. When there are two certificates, it’s fine if you don’t reverse the chain.

  2. The default configuration for the FMC003 is there so that there is a starting point for users to add their own devices. Currently, if there is no configuration available, the Teltonika integration cannot retrieve critical information about itself, so it starts misbehaving. I recommend creating a new Teltonika Model Configuration asset first, configuring it, and then deleting the default one.

  3. The idea is that you create a different model configuration asset as described above, and then set the default model number to “FMC920”, so that OpenRemote knows that when devices connect, it should use the FMC920 asset to decode the incoming values.

  4. The ideal way is to change the environment variable itself and restart the instance. This will change the password wherever it is needed.

There is also a new version of the fleet management integration that is being worked on that should reduce a lot of these painpoints. I am looking forward to releasing that soon.

Hope this helps!