8 function modules, 248 DI / 124 DO capacity
The Siemens 6ES7313-6CE00-0AB0 is a CPU 313C from the SIMATIC S7-300 family, a compact PLC that integrates 8 function modules (FM) on a single backplane — enough for most mid-size machine control loops without an expansion rack. It handles up to 248 digital inputs and 124 digital outputs, with a maximum address space of 1,024 bytes for inputs and 1,024 bytes for outputs. The work memory is 16 kbyte, enough for the STEP 7 V5.1 SP2 application code and data blocks typical of a medium-complexity logic sequence.
Programming languages and MPI-free architecture
The CPU supports LAD, FBD, STL, SCL, GRAPH, and HiGraph — the full IEC 61131-3 set except for S7-SCL (which is listed as 'Yes' via the STEP 7 environment). Notable: MPI is not supported (: No), so the only onboard programming interface is the integrated PROFIBUS DP port — you will need a CP or a PC adapter for MPI-only tools. The CPU can act as a PROFIBUS DP server (slave), but not as a client (master) — it listens on the bus for configuration data from a DP master.
Panel footprint and mounting constraints
The module measures 120 mm wide × 125 mm high × 130 mm deep — it snaps onto a standard DIN rail in the S7-300 profile, leaving room for up to 8 additional signal modules on the same rail. The 24 VDC supply is isolated (: Isolated Yes), so the CPU can share a power supply with field I/O without ground-loop issues, as long as the total draw stays within the 10 A per-rail limit. A 2-wire proximity sensor can be connected directly to the inputs (: Yes), which saves a terminal block per sensor on the panel.