Active S7-200 CPU 224 — 14 inputs, 10 relay outputs, 24 VDC
The Siemens 6ES7214-1BD23-0XB0 is an S7-200 CPU 224 compact PLC with 14 digital inputs and 10 relay outputs, powered by 24 VDC (20.4 V to 28.8 V permissible range). Programming is supported in FBD, LAD, and STL — the full IEC 61131-3 set for this platform — with a command set covering bit logic, integer and floating-point math, timer/counter, and communications instructions. The 32-byte accumulator size handles the typical S7-200 scan cycle.
Communication and I/O — MPI, PPI, and high-speed counters
The integrated RS 485 interface supports both MPI (up to 187.5 kbit/s, as slave to S7-300/S7-400 CPUs, OPs, and TDs) and PPI (9.6/19.2/187.5 kbit/s for programming, HMI, and CPU-to-CPU communication). Shielded cable runs up to 500 m; unshielded up to 150 m. Six high-speed counters (30 kHz each, 32-bit including sign) handle up/down counting and dual incremental encoder inputs with 90° offset (A/B counters, max 20 kHz). The parameterizable enable/reset and interrupt-on-setpoint allow direct subroutine calls without polling the scan.
Memory retention and backup — EEPROM and capacitor
The entire program is stored maintenance-free on integral EEPROM; DB 1 current values are held in RAM with retentive bits, timers, and counters backed by a high-performance capacitor. Typical backup time is 100 h (min. 70 h at 40 °C), extendable to 200 days with the optional battery module.