The Siemens 6AG1211-0BA23-2XB0 is an S7-200 CPU unit rated for 24 V DC supply with a permissible range of 20.4 V to 28.8 V DC. Typical power loss is 6 W. It supports FBD, LAD, and STL programming languages, making it compatible with existing S7-200 codebases. Four high-speed counters (30 kHz each) are available for incremental encoder inputs or up/down counting, each 32-bit with sign. Parameterizable enable and reset inputs allow interrupt-driven subroutine calls on reaching setpoints. Retentive memory is maintained by a high-performance capacitor: minimum 8 hours at 40 °C, up to 50 hours. An optional battery module extends retention to 200 days typical. The program and DB1 data reside on integral EEPROM — no battery needed for program storage. The integrated RS 485 interface supports MPI (up to 187.5 kbit/s) and PPI protocols for HMI (TD 200, OP) and CPU-to-CPU communication. Unshielded cable runs up to 150 m, shielded up to 500 m.
Timers and program execution
Timer range spans three groups: four timers with 1 ms to 30 s resolution, sixteen timers from 10 ms to 5 min, and 236 timers from 100 ms to 54 min. Program processing can be free-cycle (OB 1), interrupt-driven, or time-controlled (1 to 255 ms). Digital input thresholds: 0 to 5 V for signal 0, minimum 15 V for signal 1. Two-wire sensors are supported. Inputs can be configured as source or sink per group.