Product Overview

The Yokogawa AAI841-H50/K4A00 is a versatile, high-density hybrid module designed for the CENTUM VP and CS 3000 Distributed Control Systems. This hardware solution integrates both input and output functionalities into a single card, offering 8 channels for analog signal acquisition and 8 channels for analog control output. Featuring the "H" designation for HART digital communication, it enables seamless bidirectional data exchange with smart field instruments. The inclusion of the /K4A00 option provides a factory-fitted KS Cable Interface Adapter (Model ATK4A-00), significantly simplifying the interconnectivity between the I/O node and the terminal field wiring. This dual-purpose module is ideal for applications where space optimization within the FIO node is a priority without sacrificing high-precision control.

Technical Infrastructure and Hardware Logic

• I/O Configuration: 8 Analog Inputs / 8 Analog Outputs (Non-isolated)

• Input Signal Capability: 4 to 20 mA or 1 to 5 V DC

• Output Signal Range: 4 to 20 mA DC

• Digital Communication: HART Protocol Support (Versions 5/6/7)

• Sampling Rate: 10 ms data update period

• Measurement Accuracy: Input ±16 µA; Output ±48 µA

• Transmitter Power: 14.8 V minimum (at 20 mA) to 26.4 V maximum

• Interface Hardware: Integrated KS Cable Adapter (ATK4A-00)

• Current Consumption: 450 mA at 24 V DC

• Mass: 0.3 kg (Approx. 300g)

• Physical Footprint: 130 mm (H) x 32.8 mm (W) x 107.5 mm (D)

Functional Deployment and Process Utilities

The AAI841-H50/K4A00 is frequently deployed in localized control loops where both sensing and actuation are managed within the same geographic area of a plant. Key applications include:

• Closed-Loop Control: Managing simple PID loops where the module receives 4-20 mA feedback from a transmitter and sends a 4-20 mA control signal to a valve positioner.

• Smart Device Calibration: Utilizing the HART pass-through feature to monitor device health and perform remote maintenance on both sensors and actuators.

• Skid-Mounted Systems: Reducing the footprint of control cabinets in modular process units by consolidating I/O types onto a single module.

• HVAC and Utilities: Controlling fans and pumps while simultaneously monitoring pressure or flow rates in non-critical plant utility systems.

FAQ

Q: Does the AAI841-H50/K4A00 provide channel-to-channel isolation?

A: No, this is a non-isolated module. All 8 inputs and 8 outputs share a common ground. For applications requiring complete galvanic separation between channels, individual isolated modules should be utilized.

Q: What is the purpose of the ATK4A-00 adapter included with this module?

A: The /K4A00 adapter provides a KS cable interface, which allows the module to be quickly connected to a terminal board via a multi-core KS cable rather than individual pressure clamp wiring.

Q: Can I use this module to power a 2-wire transmitter?

A: Yes, the module provides an internal transmitter power supply with a minimum of 14.8 V at 20 mA, making it compatible with most standard 2-wire loops.

Q: How does the HART communication function on the output channels?

A: On the output side, HART allows the system to communicate with smart positioners or actuators to read valve travel data or diagnostic alerts while simultaneously providing the 4-20 mA control signal.

Q: What is the maximum distance supported for the KS cable interface?

A: The distance depends on the cable type used, but standard Yokogawa KS cables are typically rated for distances up to 50 meters between the module and the terminal board.