Analog input module | 8 inputs | 24VDC | 6ES7231-4HF32-0XB0 Siemens

Technical Specifications

Model: SM 1231, AI 8x13 bit
Number of inputs: 8 analog channels (differential)
Measurement modes:
• Voltage: ±10 V, ±5 V, ±2.5 V (input impedance ≥9 MΩ)
• Current: 0–20 mA, 4–20 mA (input impedance 280 Ω)
Resolution: 12 bits + sign (13-bit ADC)
Measurement accuracy: ±0.1 % at 25 °C
Conversion time: up to 625 µs for all channels
Power supply: 24 V DC, typ. consumption 60 mA
Protection: diagnostics, power supply monitoring, wire break detection, LED indicators
Operating temperature: –20 … +60 °C (horizontal), up to +50 °C (vertical)
Protection class: IP20
Dimensions: 45 × 100 × 75 mm
Weight: ~180 g
Compliance: CE, UL, CSA, cULus, RCM, KC, Marine Approval

Functions

High-resolution analog signal measurement (current and voltage modes).

Seamless integration with SIMATIC S7-1200 controllers via board connector.

Flexible parameterization (filtering, integration time, noise suppression).

Integrated diagnostic functions ensure system reliability and fast fault detection.

Compact DIN rail design – easy installation.

Applications

For engineers: ideal for industrial process control – measuring temperature (via sensor signal converters), pressure, flow, position, or other physical values.

For electricians: simple to install and connect to SIMATIC S7-1200 PLC, ensuring reliable signal transmission.

For automation system integrators: useful in designing energy efficiency, production line, HVAC, water supply, or transport control solutions.

Pros

High measurement accuracy class (±0.1 %).

Fast response time – up to 625 µs for all channels.

Compact size and easy installation.

Wide operating temperature range.

Integrated diagnostics (LED indicators, power monitoring, wire break detection).

Certified (CE, UL, CSA, Marine Approval) – suitable for various markets.

Cons

Limited protection class (IP20) – unsuitable for humid or dusty environments without additional protection.

No direct thermocouple or RTD sensor support (requires additional converters).

Designed only for SIMATIC S7-1200 systems – incompatible with other PLCs without additional interfaces.