Siemens 6ES7 235-0KD00-0XA0 Analog Input Output Expansion

Siemens EM235, 6ES7 235-0KD00-0XA0, is an analog input/output expansion module for the SIMATIC S7-200 family that adds three analog input channels and one analog output channel to a compatible CPU via the built‑in expansion port. This 3 AI/1 AO module delivers compact, mixed‑signal I/O with 12‑bit data resolution, enabling precise sensing and control of analog signals in small automation applications. The AI channels support common industrial signal ranges used for temperature, pressure, and process variables, while the AO channel provides a corresponding analog control output. Data words from the AI inputs and the AO output are mapped into the PLC I/O image for straightforward integration. Typical uses include temperature monitoring with remote sensors, level or flow measurement, and simple analog control loops in compact panels where space is at a premium. The EM235 family is designed to slot into the S7‑200 expansion bus and be configured in Step 7 Micro/WIN or related Siemens software, with channel data words allocated as part of the CPU’s I/O image. The 6ES7 235-0KD00-0XA0 variant specifically identifies the 3‑analog‑input plus 1‑analog‑output configuration, distinguishing it from other EM235 variants that offer different channel counts.