What does it mean when "Lost Frames" occur in the EtherCAT bus?
There is little we can do. A "Lost Frame" is a HW problem and it happens when the PHY has no link. We can only recommend cable and/or device replacement. See here:
https://www.ethercat.org/download/documents/EtherCAT_Diagnosis_For_Users_DE.pdf
Is it possible to change the Device ID by an EtherCAT controller?
Yes you can do this with by the Station Alias Configuration via the EtherCAT Master. You can find the documentation in the ETG 1020 chapter 18 - Explicit Devie Identification:
Sie können das mit dem Station Alias Konfiguration über den EtherCAT Master machen. Sie finden die Dokumentation im ETG 1020 Kapitel 18 - Explicit Device Identification. Here it says:
The Device Identification value can be set
by an ID-Selector, locally on the slave This can be a Switch (e.g. Rotary- or DIP-switch) or set via a display control stored non-volatile. The ID-Selector should have a length of 16 Bit.
For example Modbus Registers, etc.
by a configuration tool in the SII Configured Station Alias The value of the SII is automatically loaded during boot-up of the ESC to the Configured Station Alias Register (0x0012).
By using the EtherCAT Controller