CPU 315F — safety-rated S7-300 with 128 KB
The Siemens 6ES7315-6FF00-0AB0 is a SIMATIC S7-300 CPU 315F central unit for S7-300F fail-safe applications. It packs 128 KB working memory, two interfaces (one MPI/DP and one DP), and an integrated 24 V DC power supply. A micro memory card is required to operate. This CPU handles 248 digital inputs and 124 digital outputs, with a maximum of 2048 bytes of address space and up to 4 racks of 8 modules each. Bit operations execute in 0.1 µs typical, and the interrupt response time is 400 µs.
PROFIBUS DP and MPI connectivity
Both PROFIBUS DP master and slave modes are supported on the DP interface, with a maximum transmission rate of 12 Mbit/s and up to 32 DP slaves or 32 nodes total. The MPI interface is also present for programming and HMI communication. The CPU mounts on a standard S7-300 DIN rail profile. Dimensions are 120 mm wide, 125 mm tall, and 130 mm deep — it occupies three module slots in the rack.
End-of-life status and sourcing
For a replacement, consult the Siemens S7-1200 or S7-1500 family for equivalent fail-safe functionality, or source this exact unit through the surplus market.