This is the 6AG1215-1AG31-4XB0, a SIPLUS S7-1200 CPU from Siemens built for environments where standard controllers can't hack it — the -40 to 70 °C range means it'll sit in a hot panel next to a pump or out in the cold without complaint. It runs on 24 V DC, talks PROFINET natively, and also handles UDP, MODBUS TCP/IP, PROFIBUS, and AS-Interface out of the box. The 4 MB integrated memory gives you room for larger code and tag databases, and the 8 kbyte bit memory keeps your logic tight. Program it in LAD, FBD, or SCL — whatever your team is comfortable with. Forcing and online diagnostics are present, so troubleshooting on the route is straightforward.
How it compares to the 6AG1215-1AG40-4XB0
The sibling 6AG1215-1AG40-4XB0 is a later hardware revision — the 1AG31 here is the previous step. Both are SIPLUS variants with the same -40 to 70 °C rating, same memory, same PROFINET, same physical footprint (130x100x75 mm), so it'll drop into the same panel cutout and DIN rail without rewiring. Functional specs are identical across all listed languages and protocols; the 1AG31 carries an earlier firmware revision than the 1AG40.
Dimensions: 130 mm wide, 100 mm high, 75 mm deep — fits any standard S7-1200 panel cutout. DIN-rail mount, spring-cage terminals on the removable connector. Analogue inputs on the CPU accept 0 to +10 V or 0 to 20 mA, adjustable per channel. Good for reading pressure transmitters or level sensors directly, no separate input module needed.