Product Introduction

The Yokogawa AAI835 is a high-performance Analog Input Module designed for the CENTUM VP and CS 3000 control systems. It is part of the Yokogawa I/O subsystem, providing reliable, real-time analog signal acquisition for industrial automation processes. The AAI835 module is engineered to collect accurate and consistent data from field instruments such as temperature sensors, pressure transducers, and flow transmitters. It supports a wide range of input types including voltage, current, and thermocouple signals.

This module is widely used in sectors such as power generation, petrochemical, oil and gas, pharmaceuticals, and water treatment plants. Its robust design, combined with Yokogawa’s engineering excellence, ensures high signal integrity, noise immunity, and long-term operational stability, making it a key component in distributed control system (DCS) architectures.

Product Advantages

• High Accuracy & Precision: Supports high-resolution signal acquisition ensuring optimal measurement fidelity.

• Versatile Signal Handling: Capable of processing a variety of analog signals including 4–20 mA, 1–5 V, thermocouples, and RTDs.

• Noise Immunity: Engineered with advanced filtering and shielding to minimize noise interference, ensuring stable signal processing.

• Modular Design: Simplifies system configuration and maintenance; modules can be easily replaced or upgraded.

• Hot Swap Capability: Enables replacement without powering down the system, reducing downtime during maintenance.

• Advanced Diagnostics: Built-in diagnostics for signal status, wiring integrity, and module health monitoring.

• Compatibility: Fully integrates with Yokogawa’s ProSafe-RS and CENTUM VP platforms for seamless operation.

Technical Specifications

Applications

• Oil & Gas Refining: For acquiring critical temperature and pressure measurements in refineries.

• Power Generation: Monitors generator outputs, transformer temperatures, and process flows.

• Chemical Processing: Used to ensure accurate dosing, mixing, and reaction conditions.

• Pharmaceutical Manufacturing: Maintains precise environmental and process controls.

• Water and Wastewater Treatment: Facilitates monitoring of flow, pressure, and chemical injection.

• Pulp & Paper Industry: Ensures optimal temperature and chemical control for quality paper output.

Compatible Models

The AAI835 module is designed to be used alongside the following Yokogawa models and systems:

• FCS (Field Control Station): Such as AFV30D, AFV10D

• Power Supply Units: PW482, PW402

• Baseplates: ABP102, ABP104

• Processor Modules: CP451, CP471

• Analog Output Modules: AAO141, AAO145

• Digital I/O Modules: ADV151, ADV161

These modules form an integrated architecture within the CENTUM VP and CS 3000 series systems.

Installation Instructions

1. Preparation:

   • Ensure all power sources to the base unit are switched off.

   • Verify that the correct slot is available and configured in the system database.

2. Mounting:

   • Align the AAI835 with the designated slot on the base plate.

   • Push the module firmly into place until the locking tab clicks.

3. Wiring:

   • Connect analog signal wires to the terminal block according to the wiring diagram in the installation manual.

   • Confirm correct polarity and signal types (e.g., 4–20 mA, 1–5 V).

4. Power On & Testing:

   • Power on the system and verify module recognition via the engineering workstation.

   • Check input values against reference standards to ensure proper functioning.

5. Hot Swap Note:

   • If replacing a faulty module, ensure system diagnostics are used to isolate the channel before removal.

6. Maintenance:

   • Periodic verification of connections and recalibration is recommended every 12–18 months.

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Frequently Asked Questions (FAQ)

Q1: What is the main use of the Yokogawa AAI835 module?
A1: The AAI835 is primarily used for analog signal acquisition in industrial control systems. It collects data from field instruments like temperature and pressure sensors and delivers it to the control system for processing.

Q2: Can the AAI835 handle both voltage and current inputs?
A2: Yes, the module supports both voltage (1–5 V, 0–10 V) and current (4–20 mA) input signals. It is designed to accommodate mixed signal environments.

Q3: Is the AAI835 hot-swappable during operation?
A3: Yes, the module supports hot-swapping, allowing it to be replaced without shutting down the system, provided system diagnostics are followed.

Q4: What is the recommended calibration cycle for the AAI835?
A4: Yokogawa recommends periodic verification and calibration every 12 to 18 months to maintain measurement accuracy and performance.

Q5: Is the AAI835 compatible with ProSafe-RS safety systems?
A5: While it is primarily used in CENTUM VP and CS 3000, it can be integrated into ProSafe-RS systems for non-safety-related analog input functions.

Q6: What should I do if a channel on the AAI835 fails?
A6: Use the system’s built-in diagnostics to isolate the affected channel. If needed, the module can be replaced while the system is running due to its hot-swappable feature.