Siemens 6ES7331-7KF02-0AB0 S7-300 SM 331 Analog Input 8AI

Versatile analog input module for Siemens S7-300 PLC systems, supporting voltage, current, thermocouple, and resistance/RTD measurement in a single unit. 8 differential channels with galvanic isolation and configurable resolution (9/12/14 bits). Integrated diagnostics, alarm functions, and support for active backplane bus hot-swapping. A flexible solution for industrial automation requiring mixed signal type acquisition.

Applications:

• Temperature monitoring with thermocouples (Types E, J, K, L, N)

• RTD measurement (Pt100, Ni100)

• Process variable acquisition (pressure, flow, level via 4-20mA transmitters)

• Voltage signal acquisition (±10V, 0-10V, ±1V to ±10V ranges)

• Factory automation and machine building

• Process control systems requiring mixed analog inputs

Technical Specifications:

• Number of inputs: 8 analog inputs (differential, 4 channel groups)

• Supported signal types: Voltage (±10V, ±1V to ±10V, 1-5V), Current (0-20mA, 4-20mA, ±20mA), Thermocouple (E, J, K, L, N), Resistance/RTD (Pt100, Ni100)

• Resolution: Configurable 9/12/14 bits per channel group

• Input resistance: Voltage 100kΩ, Current 25Ω, Resistance 10MΩ

• Isolation: Galvanic isolation between channels and backplane bus

• Diagnostics: Module-level diagnostic alarm, configurable limit value monitoring, wire break detection (for current signals, ≤3.6mA triggers fault)

• Supply voltage: 24V DC (L+), reverse polarity protection

• Power loss: Typical 1W

• Dimensions (approx.): 125 mm x 40 mm x 120 mm (H x W x D)

• Weight: Approx. 250 g (module only)

Compatibility:

• SIMATIC S7-300 CPUs (all variants supporting SM modules)

• ET200M distributed I/O stations (supports hot-swapping with active backplane bus)

• STEP 7 (classic) and TIA Portal via HW Config

• Requires 20-pin front connector (not included)

Related Products:

• 6ES7331-1KF02-0AB0 – SM 331 AI 8x13 bits (simplified measurement functions)

• 6ES7331-7KF02-0AB0 – SM 331 AI 8x12 bits isolated (current model)

• 6ES7331-7HF01-0AB0 – SM 331 AI 8x13 bits isolated (faster conversion, higher accuracy)

• 6ES7332-5HD01-0AB0 – SM 332 AO 4x12 bits (isolated analog output)

For higher channel count or different accuracy requirements, consider other S7-300 SM 331 variants.

Product Status:
Legacy product, active spare part for existing S7-300 installations. Requires external 20-pin front connector for wiring.

PLC ERA is an independent industrial automation distributor. Products are sourced through established supply channels and inspected prior to shipment. International shipping available.