Safety CPU with integrated PROFIsafe
The 6ES7515-2FM00-0AB0 is a failsafe CPU that can execute safety-related logic directly without a separate safety module. It supports FBD and LAD programming with failsafe extensions, and communicates safety data over PROFINET via PROFIsafe. The 32 kbyte process image for both inputs and outputs is the working memory for I/O data — enough for a mid-sized safety application with several hundred digital and analog channels. All inputs and outputs are in the process image, so no partial-image mapping is needed.
Deterministic networking and redundancy
IRT (Isochronous Real-Time) support means this CPU can synchronize drives and I/O to within microsecond jitter — required for high-speed motion control over PROFINET. MRP (Media Redundancy Protocol) is supported as both manager and client, with up to 50 devices in a ring, so a single cable break does not drop the network. The CPU also runs standard IT protocols: TCP/IP, UDP, HTTP/HTTPS for web server pages, SNMP for network management, and MODBUS TCP for legacy device integration. DHCP is not supported — addresses must be set manually or via DCP.
Programming and memory
Programming languages include LAD, FBD, STL, SCL, and GRAPH — the full IEC 61131-3 set plus GRAPH for sequential control. The maximum user program size is 16 kbyte, which constrains the application to compact logic; for larger programs, step up to the 1516 or 1518 CPUs. The hardware clock maintains time for 6 weeks at 40°C ambient without power. The backup time is sufficient for weekend shutdowns but not extended storage — plan for battery replacement if the CPU sits unpowered for months. PID controllers for temperature and valve positioning are integrated, with automatic optimization routines — no external loop controller needed for simple process loops.
Physical fit and expansion
Dimensions are 70 mm wide, 129 mm deep, 147 mm high. The CPU snaps onto the standard DIN rail and connects to the backplane bus via the integrated connector. Up to 8 communication modules (CMs or CPs) for PROFIBUS, additional PROFINET, or Ethernet can be inserted to the right of the CPU. The integrated PROFINET interface runs at 100 Mbps. Status LEDs for ERROR and MAINT are present on the front panel, giving immediate visual indication of hardware faults and maintenance requests without needing the TIA Portal.