Description

Yokogawa ASI133-H00 FIO Analog Input Module

Configured for 4-20 mA analog signal acquisition in Yokogawa CENTUM VP / FIO I/O architecture, the Yokogawa ASI133-H00 (ASI133-H00 Analog Input Module) provides direct electrical interface for field transmitter current loop measurement and A/D conversion through isolated input channels.

Hardware Specifications

Parameter	Specification
ModelBrand	Yokogawa ASI133-H00
Origin	Not specified
Weight	Approx. 0.30 kg
Dimensions	Not specified
OperatingTemp	Not specified (industrial module class, typical DCS range assumed by system design)
PowerConsumption	5 VDC: 150 mA / 24 VDC: 450 mA
Input Signal	4-20 mA DC
Channels	8 channels, isolated
Withstanding Voltage	1500 VAC
Input Resistance	400 Ohm to 925 Ohm (power ON condition dependent)
Accuracy	+/-16 uA
Step Response Time	100 ms
Data Update Period	10 ms
HART Support	Available
Transmitter Supply	16 VDC or higher (20 mA current limited)

Yokogawa 4-20 mA HART Channel Isolation Architecture

The ASI133-H00 implements channel-to-system galvanic isolation for each of the 8 input channels, enabling independent loop measurement without shared reference drift. The 4-20 mA interface is designed to maintain measurement linearity under variable loop impedance conditions, while preserving HART FSK signaling integrity across the same current loop.

HART communication is transparently passed through the input circuitry, allowing bidirectional digital overlay without interrupting analog conversion. The isolation barrier supports suppression of ground potential differences between field transmitters and system backplane, maintaining stable conversion accuracy within +/-16 uA tolerance.

Frequently Asked Questions

Q: Can the ASI133-H00 accept both 2-wire and 4-wire transmitters?
A: Yes. Input impedance and loop supply design support both 2-wire loop-powered and 4-wire externally powered 4-20 mA transmitters, with independent channel isolation.

Q: Does channel isolation allow shared field grounding?
A: No. Each channel is galvanically isolated from system ground, preventing shared ground reference coupling across channels.

Q: What happens to HART signals during A/D conversion?
A: HART FSK signals are superimposed on the 4-20 mA loop and pass through the input stage without attenuation of digital modulation components.

Field Installation Guidelines

Field wiring shall maintain twisted-pair routing for each 4-20 mA loop, with shield termination performed at a single control cabinet ground point only. Do not distribute shield grounding across field junctions.

Loop supply polarity must be verified before energizing transmitter circuits. Input terminals must not exceed allowable input current of 22.5 mA per channel.

Maintain separation between analog input wiring and high-voltage or switching conductors to reduce induced coupling on low-level current loops. Ensure proper seating of pressure clamp terminals (ATSA3 series) before power application.

Specifications

• Brand: Yokogawa

Advantages

• High reliability in industrial environments
• Supports continuous operation
• Compatible with major PLC/DCS systems