1. General

1.1. Which languages does Alexa-KNX support?

Alexa-KNX supports German and English. The English language version has been designed for and tested extensively with English-GB Alexa environments. For the smart home skill, however, French is in planning. Also see 3.2.

1.2. Is there a limit to the number of devices or KNX group addresses that I can use with Alexa-KNX?

There is no principal limit in Alexa-KNX. Due to the maximum size of the JSON-configuration file of currently 50kB, though, the maximum number of devices/KNX group addresses is estimated to be approximately 550.
Note that Amazon artificially limits the Smart Home Skill to 300 devices.

1.3. Can I transfer the license if I need to swap my Gira HomeServer?

Yes, your license can be transfered to your new server.

1.4. Is the license time-limited?

No, the license is perpetual.

1.5. Will Alexa-KNX also work with future firmware versions of the Gira HomeServer?

We cannot guarantee that or when there will be an updated version for future firmware versions. Please check that your Gira HomeServer runs one of the supported firmware versions before purchasing a license.
Please note that no refund will be given in case of incompatibility with future firmware versions.

1.6. What happens if Alexa-KNX ceases to be usable, for example if Amazon should discontinue the Alexa service or the Smart Home Skill API V2?

The license is guaranteed to run for 12 months from date of purchase. Should the license become unusable during this period you are entitled to a time-proportial refund (so a twelveth of the license fee for each non-performance month during the first year).

1.7. If I use a communication object to switch off the main logic module using the "E1 Start/Stop“ input Alexa becomes unable to send any commands but, after switchig it on again, previously given commands will be executed. Can this behaviour be avoided?

No. Switching the Alexa-KNX connection on or off is not immediate/synchrnous with the command for technical reasons. Voice commands that are given up to approximately 20 seconds after switching off and up to one minute before switching on may be executed, regardless.

2. Smart Home Skill

2.1. How can I reset my device list?

The Alexa device list can only be reset in the Alexa browser interface and not in the Alexa app (iOS/Android). You can find this function on your regional Alexa website, so for the UK on https://alexa.amazon.co.uk, using "Smart Home¹ -> Devices² -> Button Forget All³" (scroll to the very bottom).

3. Custom Skill

3.1. Why does the Custom Skill try to understand and execute a voice command, even if the voice command is obviously non-sensical?

The Custom Skill has no ability to differentiate between sensical and non-sensical voice commands. Alexa's voice recognition will attempt to map any spoken phrase to a command. This means that even voice commands like "Alexa, tell My Home blah blah blah" may result in a Gira HomeServer command being executed.

3.2. Could it be that Alexa better understands my commands when using the Smart Home Skills versus the Custom Skill?

Unfortunately, the so-called interaction model of the Custom Skill cannot be generated dynamically. Therefore, the Custom Skill will always use the static lists of device and room names defined in the Custom Skill (by the Alexa-KNX developers). If you use device or room names that are not on these lists your commands may not be understood as reliably or not at all We try to enhance these lists with every release, including based on feedback from users. Also see 1.1.

4. Technology

4.1. Where is the connecting interface hosted?

The connecing interface is hosted on AWS (Amazon Web Services).

4.2. How does the connextion to AWS work?

The main logic module runs on your Gira HomeServer and initiates an encrypted connection (up to firmware version 4.5 using SSL/TLS 1.0; higher versions using SSL/TLS1.2) to an AWS server. As this connection is initiated from within the LAN of the user (and not from the outside) it is not necessary to set up a port forwarding in your internet router.
Should this connection get interrupted for any reason the logic module will continously attempt to re-initiate the connection to the AWS server (in increasing intervals of 20, 40, 80, ..., 1800 seconds).

4.3 Alexa-KNX can not connect anymore

The log will show the red bordered message in the log:
Please check if "date/time" is correct on the HomeServer, because these are necessary for a successful connection of Alexa-KNX.
To maintain the correct "date/time" it is strongly recommended to use the "NTP/Time calibration" feature of the HomeServer under "Project Settings => Network => NTP/Time calibration".
You can either use the option "Synchronise with NTP server" or, if you are using an accurate timer on the KNX side, also use the Date/Time received from EIB option.