Siemens 6ES7231-5PB50-0XB0 SIMATIC S7-1200 SB 1231 RTD AI 2x RTD Signal Board

The Siemens 6ES7231-5PB50-0XB0 is a SIMATIC S7-1200 SB 1231 RTD signal board with 2 analog inputs for Pt100, Pt1000, Ni100, Ni1000, and other resistance-thermometer types, offering 15-bit plus sign resolution and +/-0.1% accuracy at 25 C. It supports cable runs up to 100 m shielded, provides 707 V DC isolation, carries an IP20 rating, and weighs only 29 g, mounting directly on the CPU's signal-board slot.

Technical Specifications

Certifications & Standards

• CE mark
• UL approval
• cULus
• RCM
• KC approval

Selection Notes

The board reads 15 resistance-transmitter types (Pt, Ni, Cu, and raw resistance ranges) under a single ordering number, so the same board covers Pt100 and Pt1000 sensors without a separate SKU per sensor type - the type is selected in the hardware configuration, not at purchase. At 15 x 62 x 63 mm it mounts directly on the CPU's signal-board slot, adding RTD inputs without consuming a base-unit expansion slot or DIN-rail space. +/-0.1% accuracy at 25 C fits process-temperature monitoring rather than laboratory-grade calibration work.

Applications

Used for direct RTD temperature sensing - motor winding temperature, bearing temperature, process fluid temperature - on compact S7-1200 CPUs where a full I/O module isn't justified for two channels.