The Siemens 6ES7195-0BE21-0XA0 is a SIMATIC DP ASIC DPC31 Step B for PROFIBUS DP slave applications. It integrates an 80C32 processor core and the PROFIBUS protocol in one 100-pin PQFP package, drawing 50 mA from a 3.3 V rail. Transmission rate goes to 12 Mbit/s with automatic baud detection, and it carries 6 kbyte of telegram memory for the data exchange.
Where it lands in the design
This is the core for an intelligent PROFIBUS DP slave node — the ASIC handles bus access in hardware, so you don't need a separate microcontroller for the protocol stack. It suits light-to-medium slave designs needing up to 24 KB of firmware footprint (the scope of firmware is 4 to 24 KB). The housing footprint is 4 cm², manageable for a compact PCB.