AAI135-H00/K4A00

The Yokogawa AAI135-H00/K4A00 is an 8-channel analog input module designed to receive 4 to 20 mA current signals from field instruments. It provides isolated input channels, HART digital communication, and an input-to-system withstand voltage of 500 V AC for 1 minute. The K4A00 option specifies a KS Cable Interface Adapter, model ATK4A-00, for the cable connection interface.

Functional Description

The AAI135-H00/K4A00 converts field current signals into input data for the Yokogawa control system. Its eight input channels accept standard 4 to 20 mA signals, allowing multiple transmitters to be connected through one module.

The H suffix identifies the HART communication configuration. HART uses digital communication superimposed on the conventional 4 to 20 mA current loop, allowing compatible field devices to exchange additional digital information while retaining the analog measurement signal.

Channel Isolation and Electrical Characteristics

The module provides isolated input channels, with a specified withstand voltage of 500 V AC for 1 minute between input and system, and between input channels. These isolation characteristics define the electrical separation between the input circuits and system circuitry, as well as between individual input channels.

The allowable input current is 25 mA. Input resistance varies with the operating condition: when powered on, it ranges from 290 ohm at 20 mA to 450 ohm at 4 mA. When power is off, the input resistance is 500 kohm or greater.

K4A00 Cable Interface Configuration

The K4A00 option specifies a KS Cable Interface Adapter, identified as ATK4A-00. This adapter is part of the specified connection configuration and should be considered when checking replacement requirements or confirming the existing cabinet wiring arrangement.

The complete ordering number AAI135-H00/K4A00 should be retained when identifying this configuration, rather than treating it as a generic AAI135 module.

Technical Specifications

Parameter	Specification
Model	AAI135-H00/K4A00
Brand	Yokogawa
Product Type	Analog Input Module (Current Input)
Number of Input Channels	8
Channel Configuration	Isolated channels
Input Signal	4 to 20 mA
Allowable Input Current	25 mA
Digital Communication	HART protocol
Input Resistance (Power ON)	290 ohm at 20 mA to 450 ohm at 4 mA
Input Resistance (Power OFF)	500 kohm or greater
Accuracy	+/-16 uA
Withstand Voltage (Input to System)	500 V AC for 1 minute
Withstand Voltage (Between Input Channels)	500 V AC for 1 minute
Cable Interface Adapter	ATK4A-00
Weight	0.3 kg

Model Configuration

The ordering number identifies the module and its specified communication and cable interface configuration.

Code	Description
AAI135	8-channel, isolated 4 to 20 mA analog input module
H	Digital communication with HART protocol
00	Basic type
K4A00	KS Cable Interface Adapter configuration
ATK4A-00	Associated KS Cable Interface Adapter model

Frequently Asked Questions

Q: Does the AAI135-H00/K4A00 support HART communication?

A: Yes. The H suffix identifies the HART communication configuration. It supports digital communication over the 4 to 20 mA current loop, in addition to the analog input signal.

Q: Are the eight input channels electrically isolated?

A: Yes. The module specifies isolated input channels, with a withstand voltage of 500 V AC for 1 minute between input channels. It also specifies 500 V AC for 1 minute between the input and system circuits.

Q: Which cable interface adapter is specified for the AAI135-H00/K4A00?

A: The K4A00 option specifies the KS Cable Interface Adapter ATK4A-00. This model should be checked when verifying the cable interface configuration for a replacement module.

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