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 6ES7231-5QD32-0XB0 is a SIMATIC S7-1200 SM 1231 TC module with 4 thermocouple input channels supporting Types B, C, E, J, K, N, R, S, T, and TXK/TXK(L), each resolving to 15 bit plus sign. It draws 40 mA typical and dissipates 1.5 W, with wire-break diagnostics and ±0.1% accuracy at 25°C across the total measurement range.
With 4 channels against the SB 1231 TC signal board's single channel, the SM 1231 TC suits multi-zone temperature monitoring -- a 4-zone oven or extruder barrel, for example -- from one module instead of stacking signal boards across several CPUs. It also supports the full thermocouple type range (B, C, E, J, K, N, R, S, T, TXK/TXK(L)), so mixed sensor types on the same machine can share one module rather than needing type-specific hardware. As a rack-mounted SM rather than a CPU signal board, it needs a free signal-module slot and a wider footprint (45 x 100 x 75 mm) -- confirm rack space before specifying it on a 1212C, which supports fewer signal modules than the 1214C/1215C.
Multi-zone oven or furnace temperature monitoring, extruder barrel zone control, or any S7-1200 station needing 4 or more thermocouple channels of mixed sensor type.
| Product type designation | SM 1231, AI 4x16 bit TC |
|---|
| Rated value (DC) | 24 V |
|---|
| Current consumption, typ. | 40 mA |
|---|---|
| from backplane bus 5 V DC, typ. | 80 mA |
| Part number | 6ES7231-5QD32-0XB0 |
|---|---|
| Type designation | SM 1231, AI 4x16 bit TC |
| Brand | Siemens |
| Condition | New, factory sealed |
| Source | Siemens and its authorised distributors |
| Warranty | Manufacturer warranty |
| Lifecycle status | Active, in production |
| EAN | 6940408101890 |
| ETIM class | EC001420 |
| eCl@ss | 27242201 |
| Power loss, typ. | 1.5 W |
|---|
| Number of analog inputs | 4; Thermocouples |
|---|---|
| permissible input voltage for voltage input (destruction limit), max. | ±35 V |
| Technical unit for temperature measurement adjustable | Degrees Celsius/degrees Fahrenheit |
| Input ranges: Voltage | Yes |
| Input ranges: Current | No |
| Input ranges: Thermocouple | Yes; J, K, T, E, R, S, N, C, TXK/XK(L); voltage range: ±80 mV |
| Input ranges: Resistance thermometer | No |
| Input ranges: Resistance | No |
| Input ranges (rated values), voltages: -80 mV to +80 mV | Yes |
| Input ranges (rated values), voltages: Input resistance (-80 mV to +80 mV) | ≥1 MOhm |
| Input ranges (rated values), thermocouples: Type B | Yes |
| Input ranges (rated values), thermocouples: Type C | Yes |
| Input ranges (rated values), thermocouples: Type E | Yes |
| Input ranges (rated values), thermocouples: Type J | Yes |
| Input ranges (rated values), thermocouples: Type K | Yes |
| Input ranges (rated values), thermocouples: Type N | Yes |
| Input ranges (rated values), thermocouples: Type R | Yes |
| Input ranges (rated values), thermocouples: Type S | Yes |
| Input ranges (rated values), thermocouples: Type T | Yes |
| Input ranges (rated values), thermocouples: Type TXK/TXK(L) to GOST | 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 |
| Smoothing of measured values: parameterizable | Yes |
| 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), (+/-) | 0.5 % |
| 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 |
|---|
| 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 |
| eClass | 16 27-24-22-01 |
|---|---|
| ETIM | 10 EC001420 |
| IDEA | 4 3562 |
| UNSPSC | 15 32-15-17-05 |
| Miscellaneous Manufacturer Declara- Metrological Approval tion | For use in hazard- |
|---|---|
| General Product Approval EMV | ous locations |
| Net weight | 0.16 kg |
|---|---|
| Country of origin | CN |
| Shipping weight | 0.66 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 4x16 bit TC is 24 V AC.
The tariff (HS) code on file for SM 1231, AI 4x16 bit TC is 85389091.
The EAN (GTIN) of SM 1231, AI 4x16 bit TC is 6940408101890.
SM 1231, AI 4x16 bit TC 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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