The CPU 313C is the compact CPU for systems with demanding requirements regarding processing performance and speed of response. Integrated digital and analog inputs/outputs permit direct connection to the process.

Other possible uses result from the integrated technological functions:

• Counting
• Frequency measurement
• Period measurement
• Pulse-width modulation
• PID control

• 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;
  the CPU automatically saves all data (up to 64 KB) in case of a power failure so that the data are available again unchanged when the power returns.

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;
  specification of the maximum cycle time and load. Setting of the clock memory address.
• Retentivity;
  definition of the number of retentive bit memories, counters, timers and data blocks
• 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
• Analog inputs/outputs;
  setting of addresses, in the case of inputs: the temperature unit, the measurement type, the measuring range, and the interference frequency, in the case of outputs: the output type and output range
• Integrated function “counting”;
  setting the addresses, parameter assignment of the modes “continuous counting”, “single counting”, “periodic counting”, “frequency measurement” and “pulse width modulation”
• Integrated “Rules” function