Product Overview

The Siemens 6ES7231-5QD30-0XB0 is a high-performance analog input module from the SIMATIC S7-1200 series, specifically designed as a Signal Module (SM 1231) to expand the analog signal acquisition capabilities of the S7-1200 PLC system . This versatile module is engineered to interface directly with thermocouple sensors and low-level voltage sources, making it an indispensable component for precise temperature measurement and monitoring in industrial automation applications . The Siemens 6ES7231-5QD30-0XB0 establishes a seamless connection between process signals and the controller, converting millivolt-level signals from thermocouples into reliable digital data for the CPU.

Offering four isolated analog inputs with a resolution of 15 bits plus sign, the Siemens 6ES7231-5QD30-0XB0 delivers exceptional measurement accuracy, supporting a wide range of thermocouple types including J, K, T, E, R, S, N, C, and TXK/XK(L), with a voltage range of ±80 mV . The module features integrated cold junction compensation and supports diagnostic functions such as wire break detection, ensuring reliable process monitoring . Installed directly on the DIN rail adjacent to the S7-1200 CPU, the Siemens 6ES7231-5QD30-0XB0 derives its power from the backplane bus, simplifying installation and eliminating the need for additional power supplies . As a key component in the S7-1200 ecosystem, the Siemens 6ES7231-5QD30-0XB0 empowers engineers to implement sophisticated temperature control strategies across a wide spectrum of industries.

 

Technical Specifications

Parameter Name	Parameter Value
Product Model	6ES7231-5QD30-0XB0
Manufacturer	Siemens
Product Type	Analog Input Module (SM 1231 TC)
System Platform	SIMATIC S7-1200
Number of Analog Inputs	4 channels for thermocouples
Input Signal Range	±80 mV (thermocouple); also supports ±10V, ±5V, ±2.5V
Supported Thermocouple Types	J, K, T, E, R, S, N, C, TXK/XK(L)
A/D Resolution	15 bits plus sign (0.1 °C / 0.1 °F)
Measurement Accuracy	±0.1% FS (typical, 25 °C)
Conversion Time	< 0.5 ms per channel
Input Impedance	> 1 MΩ (voltage), 250 Ω (current)
Temperature Compensation	Integrated, non-parameterizable
Diagnostic Functions	Wire break detection, overflow/underflow alarm
Power Supply	From S7-1200 backplane bus (no external 24V needed)
Current Consumption (backplane)	80 mA (typical)
Power Loss	1.5 W (typical)
Operating Temperature	0 °C to +55 °C (horizontal installation)
Storage Temperature	-40 °C to +70 °C
Protection Class	IP20
Mounting	35 mm DIN rail (EN 60715)
Dimensions (W × H × D)	45 × 100 × 75 mm
Net Weight	Approx. 0.17 – 0.25 kg

 

 

Main Features and Advantages

Exceptional Temperature Measurement Precision: At the core of the Siemens 6ES7231-5QD30-0XB0 is its ability to deliver highly accurate temperature readings through dedicated thermocouple support. With a measurement resolution of 0.1 °C / 0.1 °F and 15-bit plus sign data representation, the Siemens 6ES7231-5QD30-0XB0 captures the most subtle temperature variations, ensuring that downstream control algorithms make decisions based on high-quality process data . Its support for the most common thermocouple types—including J, K, T, E, R, S, N, and C—guarantees that the Siemens 6ES7231-5QD30-0XB0 can be universally applied across different industrial processes without needing external signal conditioning .

Seamless System Integration: Engineered as an intrinsic component of the TIA Portal ecosystem, the Siemens 6ES7231-5QD30-0XB0 offers a highly intuitive engineering experience. The module is automatically recognized by the engineering software, which configures the I/O addresses and makes diagnostic information readily available . This plug-and-play approach drastically reduces the time required for project engineering and commissioning, allowing the Siemens 6ES7231-5QD30-0XB0 to be quickly integrated into new or existing S7-1200 installations.

Robust Diagnostics and Reliability: Industrial reliability is paramount, and the Siemens 6ES7231-5QD30-0XB0 is built to meet high standards of operational security. The module includes comprehensive diagnostic features such as wire break detection for current signals, which rapidly alerts the operator to sensor or wiring faults before they can cause process upsets . The Siemens 6ES7231-5QD30-0XB0 also features optical isolation between the channels and the backplane bus, protecting the control system from electrical noise and potential damage from high-voltage transients . A multi-colored LED on the module face provides immediate visual confirmation of module and channel status, accelerating troubleshooting procedures.

Compact Form Factor and Efficiency: With a space-saving width of just 45 mm, the Siemens 6ES7231-5QD30-0XB0 is optimized for applications with limited cabinet space . Its passive cooling and efficient design generate minimal heat, contributing to the overall reliability of the control cabinet. By drawing power directly from the S7-1200 backplane bus, the Siemens 6ES7231-5QD30-0XB0 also simplifies cabinet wiring, reducing the need for complex external power distribution and lowering the total cost of ownership .