Siemens 6ES7231-5QD32-0XB0 SM 1231 4-Channel 16-Bit Thermocouple Module
A four-channel S7-1200 thermocouple module with supported sensor curves and wire-break diagnostics.
Product Overview
6ES7231-5QD32-0XB0 is the four-input SM 1231 thermocouple module. Siemens lists types B, C, E, J, K, N, R, S, T and TXK/TXK(L), plus a ±80 mV voltage range.
The module uses integrating conversion and publishes 85 dB interference suppression at 50, 60 and 400 Hz. Temperature compensation is not parameterizable, so the approved reference-junction arrangement must be captured from the installation.
Readable diagnostics include supply monitoring and wire-break detection. The article uses a 24 V DC rated supply and 1.5 W typical power loss.
Performance
Thermocouple acquisition
Measures four supported thermocouple channels using the selected manufacturer curve.
Millivolt conversion
Accepts the published ±80 mV range where the project uses direct low-level voltage measurement.
Interference rejection
Applies integrating conversion with documented suppression at common interference frequencies.
Fault visibility
Reports supply and open-circuit conditions for maintenance and process diagnostics.
Technical Details
- Manufacturer
- Siemens
- Exact model
- 6ES7231-5QD32-0XB0
- Designation
- SM 1231 AI 4x16 bit TC
- Thermocouple inputs
- 4
- Supported types
- B, C, E, J, K, N, R, S, T, TXK/TXK(L)
- Voltage range
- −80 to +80 mV
- Resolution
- 15 bit + sign
- Measurement principle
- Integrating
- Interference suppression
- 85 dB at 50/60/400 Hz
- Typical current
- 40 mA
- Backplane current
- 80 mA at 5 V DC
- Typical power loss
- 1.5 W
- Diagnostics
- Supply monitoring and wire break
- Protection
- IP20
About IndustryParts
https://www.industryparts.com/Exact-model handling for 6ES7231-5QD32-0XB0
IndustryParts keeps the complete model label, requested quantity, application evidence and delivery requirements together so the proposed supply can be checked against the installed system before dispatch.
System Integration
Record the temperature chain
Identify thermocouple type, polarity, extension wire, junction practice, range and alarm limits.
Protect millivolt wiring
Separate low-level conductors from switching noise and preserve shield and grounding arrangements.
Test sensor and fault response
Apply traceable temperature or millivolt points and verify open-circuit diagnostics before release.
Applications
Furnace and heater monitoring
Reading supported thermocouples across four documented temperature points.
Machine thermal protection
Acquiring thermocouple signals used for alarms and supervised shutdowns.
Low-level millivolt input
Using the published ±80 mV range where the application documentation requires it.
FAQ
Which thermocouple types can 6ES7231-5QD32-0XB0 be configured for?
Siemens lists B, C, E, J, K, N, R, S, T and TXK/TXK(L); the selected curve must match the installed sensor.
What reference-junction information should accompany 6ES7231-5QD32-0XB0?
Provide the terminal and compensation arrangement, extension-wire type, cabinet temperature context and channel configuration.
Can an RTD replace a thermocouple on 6ES7231-5QD32-0XB0?
No. Resistance thermometers require the dedicated 5PD32 RTD module and different wiring and conversion settings.
Which checks reveal reversed polarity on 6ES7231-5QD32-0XB0?
Compare a known increasing temperature or applied millivolt signal with channel direction before relying on process alarms.
How should 6ES7231-5QD32-0XB0 be accepted after service?
Verify traceable points, correct sensor curves, stable readings, alarm response and wire-break diagnostics for all used channels.
