| Article number | 6ES7231-5PD32-0XB0 | 6ES7231-5PF32-0XB0 | 
|  | S7-1200, analog Input SM 1231 RTD, 4 AI | S7-1200, analog Input SM 1231 RTD, 8 AI | 
| General information |  |  | 
| Product type designation | SM 1231, AI 4×16 bit RTD | SM 1231, AI 8×16 bit RTD | 
| Supply voltage |  |  | 
| Rated value (DC) | 24 V | 24 V | 
| Input current |  |  | 
| Current consumption, typ. | 40 mA | 40 mA | 
| from backplane bus 5 V DC, typ. | 80 mA | 80 mA | 
| Power loss |  |  | 
| Power loss, typ. | 1.5 W | 1.5 W | 
| Analog inputs |  |  | 
| Number of analog inputs | 4; Resistance thermometer | 8; Resistance thermometer | 
| permissible input voltage for voltage input (destruction limit), max. | ±35 V | ±35 V | 
| Technical unit for temperature measurement adjustable | Degrees Celsius/degrees Fahrenheit | Degrees Celsius/degrees Fahrenheit | 
| Input ranges |  |  | 
| ● Voltage | No | No | 
| ● Current | No | No | 
| ● Thermocouple | No | No | 
| ● Resistance thermometer | Yes; Resistance-type transmitter: Pt10, Pt50, Pt100, Pt200, Pt500, Pt1000, Ni100, Ni120, Ni200, Ni500, Ni1000, Cu10, Cu50, Cu100, LG-Ni1000 | Yes; Resistance-type transmitter: Pt10, Pt50, Pt100, Pt200, Pt500, Pt1000, Ni100, Ni120, Ni200, Ni500, Ni1000, Cu10, Cu50, Cu100, LG-Ni1000 | 
| ● Resistance | Yes; 150 Ω, 300 Ω, 600 Ω | Yes; 150 Ω, 300 Ω, 600 Ω | 
| Input ranges (rated values), resistance thermometer |  |  | 
| ● Cu 10 | Yes | Yes | 
| — Input resistance (Cu 10) | 10 Ω | 10 Ω | 
| ● Ni 100 | Yes | Yes | 
| — Input resistance (Ni 100) | 100 Ω | 100 Ω | 
| ● Ni 1000 | Yes | Yes | 
| — Input resistance (Ni 1000) | 1 000 Ω | 1 000 Ω | 
| ● LG-Ni 1000 | Yes | Yes | 
| — Input resistance (LG-Ni 1000) | 1 000 Ω | 1 000 Ω | 
| ● Ni 120 | Yes | Yes | 
| — Input resistance (Ni 120) | 120 Ω | 120 Ω | 
| ● Ni 200 | Yes | Yes | 
| — Input resistance (Ni 200) | 200 Ω | 200 Ω | 
| ● Ni 500 | Yes | Yes | 
| — Input resistance (Ni 500) | 500 Ω | 500 Ω | 
| ● Pt 100 | Yes | Yes | 
| — Input resistance (Pt 100) | 100 Ω | 100 Ω | 
| ● Pt 1000 | Yes | Yes | 
| — Input resistance (Pt 1000) | 1 000 Ω | 1 000 Ω | 
| ● Pt 200 | Yes | Yes | 
| — Input resistance (Pt 200) | 200 Ω | 200 Ω | 
| ● Pt 500 | Yes | Yes | 
| — Input resistance (Pt 500) | 500 Ω | 500 Ω | 
| Input ranges (rated values), resistors |  |  | 
| ● 0 to 150 ohms | Yes | Yes | 
| ● 0 to 300 ohms | Yes | Yes | 
| ● 0 to 600 ohms | Yes | Yes | 
| Thermocouple (TC) |  |  | 
| Temperature compensation |  |  | 
| — parameterizable | No | No | 
| Analog value generation for the inputs |  |  | 
| Measurement principle | integrating | integrating | 
| Integration and conversion time/resolution per channel |  |  | 
| ● Resolution with overrange (bit including sign), max. | 15 bit; + sign | 15 bit; + sign | 
| ● Integration time, parameterizable | No | No | 
| ● Interference voltage suppression for interference frequency f1 in Hz | 85 dB at 50 / 60 / 400 Hz | 85 dB at 50 / 60 / 400 Hz | 
| Errors/accuracies |  |  | 
| Temperature error (relative to input range), (+/-) | 25 °C ±0.1%, to 55 °C ±0.2% total measurement range | 25 °C ±0.1%, to 55 °C ±0.2% total measurement range | 
| Repeat accuracy in steady state at 25 °C (relative to output range), (+/-) | 0.05 % | 0.05 % | 
| Interference voltage suppression for f = n x (f1 +/- 1 %), f1 = interference frequency |  |  | 
| ● Common mode interference, min. | 120 dB | 120 dB | 
| Interrupts/diagnostics/status information |  |  | 
| Alarms | Yes | Yes | 
| Diagnostics function | Yes; Can be read out | Yes; Can be read out | 
| Alarms |  |  | 
| ● Diagnostic alarm | Yes | Yes | 
| Diagnoses |  |  | 
| ● Monitoring the supply voltage | Yes | Yes | 
| ● Wire-break | Yes | Yes | 
| Diagnostics indication LED |  |  | 
| ● for status of the inputs | Yes | Yes | 
| ● for maintenance | Yes | Yes | 
| Degree and class of protection |  |  | 
| IP degree of protection | IP20 | IP20 | 
| Standards, approvals, certificates |  |  | 
| CE mark | Yes | Yes | 
| CSA approval | Yes | Yes | 
| UL approval | Yes | Yes | 
| cULus | Yes | Yes | 
| FM approval | Yes | Yes | 
| RCM (formerly C-TICK) | Yes | Yes | 
| KC approval | Yes | Yes | 
| Marine approval | Yes | Yes | 
| Ambient conditions |  |  | 
| Free fall |  |  | 
| ● Fall height, max. | 0.3 m; five times, in product package | 0.3 m; five times, in product package | 
| Ambient temperature during operation |  |  | 
| ● min. | -20 °C | -20 °C | 
| ● max. | 60 °C | 60 °C | 
| ● horizontal installation, min. | -20 °C | -20 °C | 
| ● horizontal installation, max. | 60 °C | 60 °C | 
| ● vertical installation, min. | -20 °C | -20 °C | 
| ● vertical installation, max. | 50 °C | 50 °C | 
| Ambient temperature during storage/transportation |  |  | 
| ● min. | -40 °C | -40 °C | 
| ● max. | 70 °C | 70 °C | 
| Air pressure acc. to IEC 60068-2-13 |  |  | 
| ● Operation, min. | 795 hPa | 795 hPa | 
| ● Operation, max. | 1 080 hPa | 1 080 hPa | 
| ● Storage/transport, min. | 660 hPa | 660 hPa | 
| ● Storage/transport, max. | 1 080 hPa | 1 080 hPa | 
| Relative humidity |  |  | 
| ● Operation at 25 ℃ without condensation, max. | 95 % | 95 % | 
| Pollutant concentrations |  |  | 
| ● SO2 at RH < 60% without condensation | S02: < 0.5 ppm; H2S: < 0.1 ppm; RH < 60% condensation-free | S02: < 0.5 ppm; H2S: < 0.1 ppm; RH < 60% condensation-free | 
| connection method / header |  |  | 
| required front connector | Yes | Yes | 
| Mechanics/material |  |  | 
| Enclosure material (front) |  |  | 
| ● Plastic | Yes | Yes | 
| Dimensions |  |  | 
| Width | 45 mm | 70 mm | 
| Height | 100 mm | 100 mm | 
| Depth | 75 mm | 75 mm | 
| Weights |  |  | 
| Weight, approx. | 220 g | 220 g |