SIMATIC S7-1500 compact CPU CPU 1511C-1 PN, central processing unit with 300 KB work memory for program and 1.5 MB for data, 16 digital inputs, 16 digital outputs, 5 analog inputs, 2 analog outputs, 6 high-speed counters, 4 high-speed outputs for PTO/PWM/frequency output 1st interface: PROFINET IRT with 2-port switch, 6 ns bit performance, including front connector push-in, SIMATIC Memory Card required