6ES7431-1KF00-0AB0 – Siemens SM 431 Analog Input Module · 8 AI · 13 bit

Siemens · SIMATIC S7-400 · isolated analog input · 8 channels · U / I / resistor

 Product Overview

• 6ES7431-1KF00-0AB0 – SM 431 analog input module for S7-400.
• Provides 8 isolated inputs, 13-bit resolution with overrange.
• Supports voltage (±10V, ±1V, 1–5V), current (±20mA, 4–20mA), and resistance (0–600Ω).
• Built-in interference suppression (50/60 Hz) and ±0.02% temperature error.
• Ideal for process automation, machine control, and legacy S7-400 systems.

 Oiltech Controls’s Insight

• This SM 431 excels in mixed-signal environments – voltage, current, and resistance on one module.
• 13-bit resolution provides reliable data for precise closed-loop control.
• Wide input range and 200 m shielded cable length make it flexible for remote sensors.
• No diagnostics function – keep this in mind for fault-tolerant designs; external monitoring may be needed.
• We recommend this module for upgrading or expanding existing S7-400 I/O racks.

 Technical Specifications

• Part number: 6ES7431-1KF00-0AB0 · EAN not specified
• Analog inputs: 8 (voltage/current) · 4 for resistance
• Resolution: 13-bit incl. sign (overrange)
• Voltage ranges: ±10V, ±1V, 1–5V (input R = 200 kΩ)
• Current ranges: ±20mA, 4–20mA (input R = 80 Ω)
• Resistance range: 0–600 Ω (usable up to 500 Ω)
• Destruction limits: 50 V (voltage) · 50 mA (current, 40 mA continuous)
• Conversion time: 23/25 ms per channel · 200 ms for all channels
• Interference suppression: 50/60 Hz (parameterizable)
• Temperature error: ±0.02 %/K (resistance) · ±0.007 %/K (other ranges)
• Operational error (full range): ±1% (voltage/current) · ±1.25% (resistance)
• Basic error (25 °C): ±0.7% (V/I) · ±0.8% (resistance)
• Isolation: between channels and backplane bus (2,120 V DC)
• Power loss: typ. 1.8 W · backplane current 350 mA
• Dimensions: 25 x 290 x 210 mm · weight ~500 g

 Compatible Devices & Systems

• ✔ SIMATIC S7-400 PLC racks (all CPU versions)
• ✔ ET200M remote I/O stations (with IM153 interface)
• ✔ Mixed signal applications – connect voltage, current, or resistive sensors
• ✔ 2-wire, 3-wire, and 4-wire transmitters (external supply for 2-wire)
• ✔ Resistance measurement with 2/3/4-wire connection – line resistance included

 Installation & Commissioning

• Plug into any S7-400 slot – no external power needed.
• Configure ranges via STEP 7 or TIA Portal.
• Shielded cables up to 200 m – keep away from high-voltage lines.
• Integration time selectable: 16.7/20 ms (50/60 Hz).
• No calibration required – factory-tested accuracy.

 Why Buy From Oiltech Controls?

• ✅ Over 15 years in industrial automation spares – we know legacy systems.
• ✅ Global shipment via FedEx, UPS, DHL – 24–28 hour dispatch.
• ✅ Every unit undergoes technical verification before shipping.
• ✅ 12-month warranty – full coverage against defects.
• ✅ Refurbished and surplus options available with test reports.
• ✅ We support obsolete control systems – keep your plant running.

 Shipping & Warranty

• Carriers: FedEx, UPS, DHL – express worldwide.
• Dispatch: within 24–28 hours after order confirmation.
• Warranty: 12 months – repair or replacement.
• Tracking number provided for every shipment.

 FAQ – Expert Q&A

• Q: Can I mix voltage and current inputs on the same module?
  A: Yes. Each of the 8 channels is configurable individually for voltage, current, or resistance. However, resistance uses 4 channels max.
• Q: What is the effective resolution for 4–20 mA signals?
  A: 13-bit including sign gives approx. 0.012% of range. For 4–20 mA, the usable span is 16 mA, providing ~0.8 µA per bit.
• Q: Does this module support HART communication?
  A: No. The SM 431 is a standard analog input. For HART, you need a dedicated HART module or external multiplexer.
• Q: How do I handle 2-wire transmitters without an external supply?
  A: You must provide an external 24V supply for 2-wire sensors. The module does not supply loop power.
• Q: What is the benefit of the 4-wire resistance measurement?
  A: It eliminates lead resistance error – critical for low-resistance sensors (e.g., RTDs). Use 4-wire for best accuracy.

Contact us:
info@oiltechcontrols.com ·
+86 158 8020 0923 (WhatsApp)

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