Yokogawa AAI835-H00 Analog Module AAI835 Isolated 4-20mA HART Ready

Product Introduction

The Yokogawa AAI835-H00 is a high-performance, combined analog interface designed for precision process control. This module features four isolated input channels and four isolated output channels, supporting the standard 4 to 20 mA signaling range. It is engineered for systems requiring simultaneous monitoring and actuation within a single slot. 

Technical Specifications

• Brand: Yokogawa
• Model: AAI835-H00
• Series: AAI835 Analog I/O
• Signal Type: 4 to 20 mA (Input and Output)
• Channel Density: 4-Channel Input / 4-Channel Output (Fully Isolated)
• Communication: HART Protocol Digital Communication Enabled
• Accuracy: Input ±16 µA / Output ±48 µA
• Data Update Period: 10 ms cycle for real-time control loops
• Input Impedance: 290 Ω (at 20 mA) to 450 Ω (at 4 mA)
• Allowable Load Resistance: 0 to 750 Ω
• Transmitter Power Supply: 15.0 V DC minimum at full scale (20 mA)
• Withstanding Voltage: 500 V AC between channels and system logic
• Maximum Consumption: 360 mA (5 V DC), 450 mA (24 V DC)
• Temperature Drift: ±16 µA per 10 °C variance
• Physical Weight: Approx. 0.30 kg

Configuration Breakdown

• AAI835 (Base Series: Analog 4-In/4-Out)
  • -H (Digital Communication: HART Protocol)
    • 0 (Safety: No Explosion Protection)
      • 0 (Basic Hardware Type)

Module Integration & Components

• Redundancy Support: Compatible with ATI3S (Single) and ATI3D (Dual Redundant) configurations.
• Adapter Options: Supports ATK4A and ATB3A interface adapters.
• Connectivity: Designed for KS1 dedicated cables and AEA4D / AEA3D terminal boards.
• Field Wiring: Supports pressure clamp terminals and MIL-spec connector interfaces.

Global PLC Spare HUB's Insight

The AAI835-H00 is a hybrid workhorse. While many modules force a choice between input or output, this unit balances both, making it ideal for localized PID control loops where space is at a premium. The inclusion of HART protocol allows for remote asset management and device diagnostics without interrupting the 4-20mA signal. In our experience, the 500V isolation between channels significantly reduces ground loop interference in complex industrial grids.

Shipping & Logistics

• Shipment Speed: Dispatched within 24-48 hours.
• Carrier Partners: Express delivery via FedEx, UPS, and DHL.
• Warranty Policy: Includes a 12-month comprehensive quality guarantee.
• Package Condition: High-integrity industrial hardware in original-spec packaging.

Typical Applications & Device Compatibility

• Control Loops: Ideal for Variable Frequency Drives (VFDs) and Control Valves.
• Field Instrumentation: Connects to Pressure, Temperature, and Flow Transmitters.
• System Hosting: Fits CENTUM VP and FIO (Field Information Overlay) nodes.
• Industry Use: Petrochemical refineries, water treatment, and power generation.

Diagnostics & Protection

• Circuit-Open Detection: Automatically triggers at current levels below 0.65 mA.
• Overcurrent Protection: Allowable input current up to 25 mA to prevent circuit damage.
• Isolation: Galvanic separation prevents fault propagation between field devices and the CPU.

FAQ (Professional Engineering Perspective)

Does the AAI835-H00 support secondary HART variables?

Yes, it enables the passage of multi-variable data from smart transmitters to the control station.

How does the module behave during a system power loss?

The input resistance shifts to 500 kΩ or larger, ensuring the field loop remains high-impedance.

Can I use this module for high-impedance loads above 750 Ohms?

No, exceeding the 750 Ω limit may cause output saturation and signal clipping.

What is the benefit of the 10ms update period in this hybrid module?

It ensures minimal lag in feedback loops, which is critical for fast-acting pressure regulation.

Are the KS1 cables mandatory for connection?

While recommended for signal integrity, MIL-connector alternatives are compatible if pin-outs match.

Selection & Purchasing Guide

• Verify if your field devices require active power from the module; the AAI835 provides >15V at full load.
• Confirm redundancy requirements; for high-availability loops, pair with the ATI3D adapter.
• Calculate total cabinet heat dissipation based on the 450mA (24V) peak consumption.
• Ensure the -H suffix is chosen if you require remote calibration via HART protocol.

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