Programmable Logic Controller Guide: Selection, Application, and Maintenance for Engineers
PLC selection guide for engineers covering IEC 61131 compliance, Siemens, Rockwell, Schneider, ABB comparison, scan time sizing, and wiring. Shop at Stoklink.
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.
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.
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.
| Product type designation | SM 1231, AI 8x16 bit RTD |
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| Rated value (DC) | 24 V |
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| Current consumption, typ. | 40 mA |
|---|---|
| from backplane bus 5 V DC, typ. | 80 mA |
| Part number | 6ES7231-5PF32-0XB0 |
|---|---|
| Type designation | SM 1231, AI 8x16 bit RTD |
| Brand | Siemens |
| Condition | New, factory sealed |
| Source | Siemens and its authorised distributors |
| Warranty | Manufacturer warranty |
| Lifecycle status | Active, in production |
| EAN | 6940408101883 |
| ETIM class | EC001420 |
| eCl@ss | 27242201 |
| Power loss, typ. | 1.5 W |
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| Number of analog inputs | 8; Resistance thermometer |
|---|---|
| permissible input voltage for voltage input (destruction limit), max. | ±35 V |
| Technical unit for temperature measurement adjustable | Degrees Celsius/degrees Fahrenheit |
| Input ranges: Voltage | No |
| Input ranges: Current | No |
| Input ranges: Thermocouple | No |
| Input ranges: Resistance thermometer | Yes; Resistance-type transmitter: Pt10, Pt50, Pt100, Pt200, Pt500, Pt1000, Ni100, Ni120, Ni200, Ni500, Ni1000, Cu10, Cu50, Cu100, LG-Ni1000 |
| Input ranges: Resistance | Yes; 150 Ω, 300 Ω, 600 Ω |
| Input ranges (rated values), resistance thermometer: Cu 10 | Yes |
| Input ranges (rated values), resistance thermometer: Input resistance (Cu 10) | 10 Ω |
| Input ranges (rated values), resistance thermometer: Ni 100 | Yes |
| Input ranges (rated values), resistance thermometer: Ni 1000 | Yes |
| Input ranges (rated values), resistance thermometer: LG-Ni 1000 | Yes |
| Input ranges (rated values), resistance thermometer: Ni 120 | Yes |
| Input ranges (rated values), resistance thermometer: Ni 200 | Yes |
| Input ranges (rated values), resistance thermometer: Ni 500 | Yes |
| Input ranges (rated values), resistance thermometer: Pt 100 | Yes |
| Input ranges (rated values), resistance thermometer: Pt 1000 | Yes |
| Input ranges (rated values), resistance thermometer: Pt 200 | Yes |
| Input ranges (rated values), resistance thermometer: Pt 500 | Yes |
| Input ranges (rated values), resistors: 0 to 150 ohms | Yes |
| Input ranges (rated values), resistors: 0 to 300 ohms | Yes |
| Input ranges (rated values), resistors: 0 to 600 ohms | Yes |
| Thermocouple (TC) Temperature compensation: Parameterizable | No |
| Measurement principle | integrating |
|---|---|
| Integration and conversion time/resolution per channel: Resolution with overrange (bit including sign), max. | 15 bit; + sign |
| Integration and conversion time/resolution per channel: Integration time, parameterizable | No |
| Integration and conversion time/resolution per channel: Interference voltage suppression for interference frequency f1 in Hz | 85 dB at 50 / 60 / 400 Hz |
| Temperature error (relative to input 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 % |
| Interference voltage suppression for f = n x (f1 +/- 1 %), f1 = interference frequency: Common mode interference, min. | 120 dB |
| Alarms | Yes |
|---|---|
| Diagnostics function | Yes; Can be read out |
| Alarms: Diagnostic alarm | Yes |
| Diagnoses: Monitoring the supply voltage | Yes |
| Diagnoses: Wire break | Yes |
| Diagnostics indication LED: for status of the inputs | Yes |
| Diagnostics indication LED: for maintenance | Yes |
| IP degree of protection | IP20 |
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| CE mark | Yes |
|---|---|
| CSA approval | Yes |
| UL approval | Yes |
| cULus | Yes |
| FM approval | Yes |
| RCM (formerly C-TICK) | Yes |
| KC approval | Yes |
| Marine approval | Yes |
| Ecological footprint: environmental product declaration Global warming potential | Yes |
| Ecological footprint: global warming potential, (total) [CO2 eq] | 43.1 kg |
| Ecological footprint: global warming potential, (during production) [CO2 eq] | 7.62 kg |
| Ecological footprint: global warming potential, (during operation) [CO2 eq] | 36 kg |
| Ecological footprint: global warming potential, (after end of life cycle) [CO2 eq] | -0.544 kg |
| Free fall: Fall height, max. | 0.3 m; five times, in product package |
|---|---|
| Ambient temperature during operation: min. | -20 °C |
| Ambient temperature during operation: max. | 60 °C |
| Ambient temperature during operation: horizontal installation, min. | -20 °C |
| Ambient temperature during operation: vertical installation, min. | -20 °C |
| Ambient temperature during storage/transportation: min. | -40 °C |
| Ambient temperature during storage/transportation: max. | 70 °C |
| Air pressure acc. to IEC 60068-2-13: Operation, min. | 795 hPa |
| Air pressure acc. to IEC 60068-2-13: Operation, max. | 1 080 hPa |
| Air pressure acc. to IEC 60068-2-13: Storage/transport, min. | 660 hPa |
| Air pressure acc. to IEC 60068-2-13: Storage/transport, max. | 1 080 hPa |
| Relative humidity: Operation at 25 ℃ without condensation, max. | 95 % |
| Pollutant concentrations: SO2 at RH < 60% without condensation | S02: < 0.5 ppm; H2S: < 0.1 ppm; RH < 60 % condensation-free |
| required front connector | Yes |
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| Enclosure material (front): Plastic | Yes |
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| Width | 70 mm |
|---|---|
| Height | 100 mm |
| Depth | 75 mm |
| Weight, approx. | 220 g |
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| Miscellaneous Manufacturer Declara- Metrological Approval | tion |
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| Net weight | 0.283 kg |
|---|---|
| Country of origin | CN |
| Shipping weight | 0.783 kg |
| Ships from | Türkiye |
| Dispatch | 12 Nov |
| Stock | In stock |
Source: manufacturer data · Last verified: 01 Nov 2026
No documents are on file for this part yet.
Ask us for the datasheetThe rated operational voltage of SM 1231, AI 8x16 bit RTD is 24 V AC.
The tariff (HS) code on file for SM 1231, AI 8x16 bit RTD is 85389091.
The EAN (GTIN) of SM 1231, AI 8x16 bit RTD is 6940408101883.
SM 1231, AI 8x16 bit RTD ships from Türkiye. Shipping calculated at checkout · import duties and taxes paid on arrival. Stock items are dispatched within 1–2 business days.
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