CPU memory and I/O count — the fit decision
The Siemens 6ES7314-6BF00-0AB0 CPU 314C-2 PtP carries 48 kbyte of integrated work memory for program and data — no memory card required for basic operation, though a Micro Memory Card can be used for firmware updates or transport. Onboard I/O handles 248 digital inputs and 124 digital outputs, enough for a medium-sized machine cell without an expansion rack.
Programming and communication profile
This CPU supports LAD, STL, SCL, FBD, and GRAPH — the full IEC 61131-3 language set for the S7-300 family, plus CFC for continuous-function chart engineering. The integrated PtP interface runs RS 485 (RS 422/485 X.27) with protocols including 3964(R), RK 512, and ASCII — direct connection to drives, barcode readers, or serial printers without a separate CP.
Panel fit and expansion
Dimensions are 120 mm wide × 125 mm high × 130 mm deep — occupies three standard S7-300 slot widths on the DIN rail. Supports up to 8 function modules (FM) and up to 4 PtP CPs or 2 LAN CPs via the backplane bus, though the compact CPU itself is not expandable with additional I/O racks.