Adding RFX usb controller

I want to link my “RFXcom USB 433mhz Controller RFXtrx433XL Transceiver” to Home assistant.
I connected this to my serial usb port of my synology 918+.
In terminal /dev/ttyUSB0/ is visible.

In ha configuration->integrations I select RFXCOM RFXtrx
connection type: Serial
Select device gives: /dev/ttyS0 -ttyS0, s/n: n/a
Result in log:
Connection timeout: failed to receive response from RFXtrx device
11:20:31 – (ERROR) RFXCOM RFXtrx

If I enter /dev/ttyUSB0: Failed to connect/

In configuration I have added the following;

RFXtrx: debug

Click on Click off

  device: /dev/ttyUSB0
  debug: true


Am I missing something?
Thanks Peter

Has this ever been solved? I do have RFXcom transceiver connected to my PI on port /ttyUSB0. So far it finds all kind of devices from the neighbors, and only one of mine. I can’t get it to connect to CoCo (KaKu) devices or my fan.