Yokogawa AAI835-S00/K4A00 CENTUM VP Isolated Current Input Module

Product Overview

The Yokogawa AAI835-S00/K4A00 provides high-density, 16-channel isolated current input capabilities for the CENTUM VP and CS 3000 Distributed Control Systems (DCS). This module specializes in capturing 4 to 20 mA DC signals with a focus on high-voltage isolation, shielding the system backplane from field-side electrical disturbances. It serves as a critical data acquisition component for large-scale process industries requiring maximum signal integrity.

Part Number Breakdown: AAI835-S00/K4A00

Yokogawa's alphanumeric coding defines the specific electrical hardware and interface configurations:

• AAI835: Base model for Isolated Current Input (4 to 20 mA, 16-channel).

• -S: Standard type performance specification.

• 0: Standard type without explosion protection (General Purpose).

• 0: Basic functional specification for standard operating environments.

• /K4A00: Includes the KS cable interface adapter, facilitating connection to the AEA4D terminal board.

Technical Specifications

We supply this module in 100% brand new, original factory condition to ensure immediate system integration.

Engineering Advantages

• Superior Isolation Barrier: Unlike standard modules, the AAI835 provides a massive 1500 V AC withstanding voltage. This protection layer prevents catastrophic system failures caused by ground loops, high-voltage surges, or severe electromagnetic interference (EMI) on the field side.

• Rapid Maintenance via KS Interface: The /K4A00 option utilizes a KS cable interface rather than traditional screw terminals. This design allows technicians to hot-swap modules or perform wiring updates at a separate terminal board, significantly reducing cabinet-side labor and downtime.

• High-Density Monitoring: 16 isolated channels in a single slot footprint optimize cabinet space. This high density reduces the total number of I/O nodes required for large-scale refineries or chemical plants, lowering the total cost of ownership.

• Robust Signal Stability: Advanced internal filtering circuitry removes high-frequency noise from the 4-20 mA loop. This ensures the control processor receives a stable, "clean" signal, which allows for tighter PID tuning and more predictable process behavior.

FAQs

• What is the primary difference between the AAI835 and the AAI135?

  The AAI835 offers significantly higher isolation (1500 V AC) compared to the AAI135 (500 V AC). Use the AAI835 in environments with heavy electrical equipment where high-voltage noise or potential ground shifts occur frequently.

• Can I use the AAI835-S00/K4A00 to power 2-wire transmitters?

  The AAI835 functions as a current sink (signal receiver). If your field instruments require loop power directly from the I/O module, you may need to implement an external 24 V DC loop power supply or consider the AAI143 series.

• Does the /K4A00 adapter come pre-mounted?

  Yes, the /K4A00 adapter is factory-fitted to the module. This allows you to plug in a standard KS1 or KS2 cable immediately to connect the module to your AEA4D terminal board.

• Is this module suitable for redundant configurations?

  Absolutely. When paired with a second AAI835 in a redundant-ready I/O nest, the modules provide seamless failover protection. If the primary module fails, the secondary takes over without interrupting the process control signal.