A system (100) comprises a device (200) commissioned into the system comprising a light sensor (220) for receiving a first optical data signal from a new device (400) located within an optical range of the device (200), and a commissioning device (300) for communicatively coupling to the device (200). The first optical data signal comprises a unique identifier associated with the new device. The commissioning device (300) comprises a first credential memory (350) for storing system credentials, a commissioning wireless communication unit (320) for receiving from the device (200) the unique identifier, being configured, after receiving the unique identifier, for transmitting the stored system credentials for enabling reception of the system credentials by the new device (400), and for establishing a wireless communication link with the new device based on the unique identifier and the transmitted system credentials for commissioning the new device (400) into the system (100).