Siemens 6ES7431-7QH00-0AB0 - Universal 16-Channel High-Density Analog Input Module

Meet the ultimate measurement solution: the Siemens 6ES7431-7QH00-0AB0. This flagship analog input module for SIMATIC S7-400 PLCs combines high channel count with exceptional versatility. It offers 16 fully isolated inputs with 16-bit resolution, capable of directly connecting to virtually any analog sensor: voltage, current, resistance, Pt100/1000 RTDs, and all major thermocouple types, complete with advanced diagnostics and alarm functions.

Why Choose This Module?

• Maximum Versatility: One module handles all common sensor types—RTDs, T/Cs, voltage, current, resistance—reducing part numbers and spare parts.
• High Channel Density: 16 isolated inputs in a standard width, saving crucial rack space in your S7-400 control cabinet.
• Sensor Power Supply: Integrated 24V DC loop power for 2-wire transmitters (4-20mA), simplifying wiring and external power needs.
• Outstanding Accuracy: High 16-bit resolution and excellent basic accuracy (e.g., ±0.15% for voltage) ensure trustworthy data for critical processes.

Complete Technical Specifications

Brand & Series: Siemens SIMATIC S7-400

Full Model Number: 6ES7431-7QH00-0AB0 (Analog Input SM 431)

Module Type: 16-Channel Universal Analog Input, Isolated

Input Channels: 16 (Voltage/Current), 8 (Resistance/RTD)

High Resolution: 16 bits

Supported Signals: Voltage, Current (2-wire & 4-wire), Resistance, RTD (Pt, Ni), Thermocouple (Types B, E, J, K, L, N, R, S, T, U)

Voltage Ranges: ±10V, ±5V, ±2.5V, ±1V, ±500mV, ±250mV, ±80mV, ±50mV, ±25mV, 1-5V

Current Ranges: 4-20mA, 0-20mA, ±20mA, ±10mA, ±5mA

RTD Types: Pt100, Pt200, Pt500, Pt1000, Ni100, Ni1000

Basic Accuracy (at 25°C): ±0.15% (Voltage/Current), ±0.3% (RTD)

Conversion Time: Configurable: 6 ms, 20.1 ms, 23.5 ms

Noise Rejection: Selectable for 50 Hz, 60 Hz, or 400 Hz interference

2-Wire Transmitter Supply: 24V DC (Up to 400 mA total for all channels)

Power from Backplane: 5V DC, max 700 mA

Module Power Loss: Typically 4.5 W

Input Impedance: 1 MΩ (Voltage/Thermocouple), 50 Ω (Current)

Max Cable Length: 200 m (50 m for thermocouples on low mV ranges)

Isolation: Channel-to-channel and channel-to-backplane isolation (Tested at 2120V DC)

Dimensions (W x H x D): 25 mm x 290 mm x 210 mm

Weight: Approximately 500 g

Installation & Sensor Connection

This module installs in any S7-400 rack slot. Its key feature is supporting 2-wire 4-20mA transmitters directly by providing loop power from the integrated 24V supply—no separate power supply needed per transmitter. For best accuracy with RTDs and resistance, use the 3-wire or 4-wire connection mode to cancel lead resistance errors. Configure each channel independently in the Siemens STEP 7 hardware configurator.

Package & Warranty

What's in the Box: One factory-new Siemens 6ES7431-7QH00-0AB0 universal analog input module.

Quality Assurance: This product is covered by a comprehensive 12-month warranty.

Fast Global Shipping

Order with confidence for quick delivery via FedEx, UPS, or DHL.

Frequently Asked Questions (FAQ)

What is the main advantage of this module over others?

Its unparalleled sensor support in a high-density 16-channel design. It eliminates the need for multiple specialized modules, simplifying design, procurement, and maintenance for complex systems with mixed sensors.

How do I power my 4-20mA sensors with this module?

For 2-wire transmitters, simply connect them. The module provides the loop power (24V) internally. For 4-wire (active) transmitters with their own power supply, use the 4-wire measurement mode.

Can I measure Pt100 with 2-wire, 3-wire, and 4-wire connections?

Yes, it supports all three connection methods. For accurate temperature measurement, always use 3-wire or 4-wire connection to compensate for cable resistance, especially with long cable runs.

What is the fastest sampling rate for all 16 channels?

At the fastest conversion time of 6ms per channel, the module can theoretically scan all 16 channels in about 96ms. Use this setting for fast-changing processes.

What diagnostics does it offer?

It provides comprehensive diagnostics including wire break detection (for current loops and RTDs), over/under-range alarms, and configurable high/low limit value monitoring with interrupt capability to alert the CPU immediately.

© 2026 Ubest Automation Limited. All rights reserved.
Original Source: https://www.ubestplc.com/
Contact: sales@ubestplc.com Phone: +86 180 3000 5825