The Siemens 3RK1002-0BB00-0AA0 is a PROFIBUS-DP interface module for 3WN1 and 3WS1 circuit breakers, letting you pull breaker status and trip data onto a PROFIBUS-DP network. It ships with a 3-meter plug-in cable, a 3.5" disk containing the device data file (GSD) and type files for COM ET200 / COM PROFIBUS, plus a German-language documentation file in WinWord 6 format.
The 3.5" disk holds the GSD file needed to configure the interface into a PROFIBUS-DP master, plus type files for Siemens' COM ET200 and COM PROFIBUS configuration tools. The WinWord 6 documentation file is in German — factor that in if your panel documentation standard is English. The 3-meter plug-in cable reaches from the breaker compartment to a nearby DP drop; for longer runs you'll need a repeater or a longer cable assembly.