Integrated PROFINET CPU with FM capability
The Siemens 6ES7315-2EH13-0AB0 is an S7-300 CPU with an integrated PROFINET interface supporting UDP and TCP communication via loadable function blocks. It ships with FM 8 configuration — meaning this CPU can accommodate up to eight function modules in its rack. The I/O process image sits at 244 bytes each for inputs and outputs, enough for medium-sized plants without needing an external IM. Programming is handled through STEP 7 V5.4 SP2 or higher, with support for CFC, FBD, LAD, SCL, STL, GRAPH, and HiGraph — covering nearly all project styles from legacy ladder to structured text. The CPU functions as both a PROFINET client and server, and it can route communication between subnets via the backplane. No separate MPI port is fitted; the PROFINET interface serves as the primary programming and network gateway.
I/O and configuration details
This CPU supports forcing of inputs and outputs, and it holds retentive data across power cycles — though a restart is required to re-establish retentive values. The variable set includes inputs, outputs, memory bits, data blocks, timers, and counters. It does not support PROFIsafe, nor is it adjustable or expandable beyond its fixed configuration. For additional communication, up to 4 CPs for LAN, 10 CPs for Ethernet, and 8 CPs for PtP can be installed.