Memory and I/O — what the 1 KB buys you
The Siemens 6ES7212-1BA00-0XB0 CPU 212 carries 1 Kbyte of program memory and supports 500 AW (statement list) instructions — enough for a small machine cell or a standalone conveyor station where the sequence fits in a few dozen rungs. The relay output variant (Rel-Vers) means each output switches via a mechanical relay contact, rated for the typical 24 VDC or 230 VAC pilot loads found in panel wiring — no need for external interposing relays on solenoid valves or contactor coils within the contact rating.
