6ES7313-6CG04-0AB Siemens SIMATIC   compact PLC controller
Core Architecture & Capabilities

• Integrated Functions for Motion: It features 3 high-speed counters (30 kHz). These are critical in servo assays for direct tracking of 24 V incremental encoder feedback loops to monitor precise motor shaft positioning. 
• Pulse Outputs: It has 3 integrated pulse outputs (2.5 kHz). These can be used for basic pulse/direction (PTO) control of low-end stepper or servo drives, though more sophisticated drives will use the bus system. 
• Working Memory: Equipped with 128 KB of integrated work memory, structured for rapid preprocessing and execution of positioning blocks. It requires an external Micro Memory Card (MMC) for program storage. 

Communication Matrix (Interfacing with Servo Drives)To command a servo drive (such as a Siemens SINAMICS V90, S120, or a third-party alternative), this CPU relies on two primary physical ports:

1. PROFIBUS DP Interface (Up to 12 Mbit/s): This is the primary method for servo integration. The CPU acts as a PROFIBUS DP Master. It transmits runtime control words (speed, position targets, enable signals) and reads status words (actual speed, position, fault flags) from the drive using standard drive profiles (like PROFIdrive). 
2. MPI (Multi-Point Interface): Typically reserved for programming via STEP 7 or connecting local HMI panels for manual servo testing and monitoring 

I/O & Hardware Integration

• Onboard I/O: The module includes 16 digital inputs and 16 digital outputs (24V DC). In a servo setup, these are directly wired to hardware limit switches (Over-travel), home/reference sensors, drive ready signals, and emergency stop circuits to trigger rapid interrupts. 
• Form Factor: It requires a 40-pole front connector for I/O wiring and operates on a standard 24V DC power supply.