Siemens 6ES7231-5PF32-0XB0 SIMATIC S7-1200 SM 1231 8xAI RTD 16-Bit Analog Input Module

The Siemens 6ES7231-5PF32-0XB0 SIMATIC S7-1200 SM 1231 RTD module provides 8 resistance-thermometer inputs supporting Pt100, Pt1000, Ni100, Ni1000, and Cu10 sensor types at up to 15-bit resolution plus sign. It runs on 24 V DC, draws 40 mA typical, and adds 80 mA on the backplane bus, dissipating 1.5 W.

Technical Specifications

Certifications & Standards

• CE
• CSA
• UL
• cULus
• FM
• RCM
• KC
• Marine

Selection Notes

This SM 1231 module reads resistance-based sensors only, across Pt100, Pt1000, Ni100, Ni1000, and Cu10 RTD types plus 150/300/600 Ohm resistance ranges; a thermocouple version of the SM 1231 family exists separately for mV-level inputs and is not interchangeable with this RTD variant. All 8 channels need a front connector ordered separately, and the 70 x 100 x 75 mm housing is a full S7-1200 expansion module rather than a CPU-mounted signal board, so it takes an expansion slot. The temperature error of plus/minus 0.1% at 25 C, widening to plus/minus 0.2% at 55 C, is worth checking against the accuracy target before specifying it on a calibration-critical loop.

Applications

Fits process temperature monitoring on S7-1200 systems: motor winding RTDs, bearing temperature, and HVAC or oven zone control where several Pt100 or Ni1000 sensors feed into one module.