The CPU 312C is equipped with the following:

• Microprocessor;
  the processor achieves a processing time of 100 ns per binary instruction.
• Extensive memory;
  64 KB high-speed work memory (equals approx. 21 K instructions) for program components relevant to execution offers sufficient space for user programs;
  SIMATIC Micro Memory Cards (max. 8 MB) as load memory for the program also allow the project to be stored in the CPU (complete with symbols and comments).
• Flexible expansion capability
  max. 8 modules, (1-tier installation)
• MPI multi-point interface
  The integrated MPI interface can establish as many as 6 connections simultaneously to S7-300/400 or to programming device, PC, OP. Among these connections, one is always reserved for programming devices and another for OPs. The MPI makes it possible to set up a simple network with a maximum of 16 CPUs via “global data communication”.
• Integrated inputs/outputs
  10 digital inputs (all for alarm processing) and 6 digital outputs are available to connect the process signals to the CPU 312C.

• Password protection;
  a password concept protects the user program from unauthorized access.
• Block encryption;
  the functions (FCs) and function blocks (FBs) can be stored in the CPU in encrypted form by means of S7-Block Privacy to protect the know-how of the application.
• Diagnostics buffer;
  the last 500 error and interrupt events are stored in a buffer for diagnostic purposes, of which 100 are stored retentively.
• Maintenance-free data backup;
  retentive data is automatically backed up by the CPU if the voltage is interrupted and is available unchanged after the voltage has been reconnected.

Parameterizable properties

The S7 configuration as well as the properties and response of the CPUs can be parameterized using STEP 7:

• General;
  definition of the name, system ID and location ID
• Startup;
  definition of the startup characteristics of the CPU and the monitoring time
• Cycle/clock memory;
  specifying the maximum cycle time and loading, setting the clock memory address.
• Retentivity;
  setting retentive areas
• Time-of-day interrupts;
  setting of start date, start time and periodicity
• Cyclic interrupts;
  setting of periodicity
• System diagnostics;
  determining handling and scope of the diagnostic messages
• Clock;
  setting the type of synchronization in the AS or on the MPI
• Protection level;
  specifying the access rights to program and data
• Communication;
  reservation of connection resources
• MPI multi-point interface;
  determining station addresses
• Digital inputs/outputs;
  setting of addresses, input delay and process interrupt
• Integrated function “counting”;
  setting the addresses, parameter assignment of the modes “continuous counting”, “single counting”, “periodic counting”, “frequency measurement” and “pulse width modulation”

CPU 312C Technical specifications