Yokogawa ATT4D-00 S2 Terminal Interface Module

Configured for dual-redundant wiring execution in Yokogawa CENTUM VP / CS 3000 systems, the Yokogawa ATT4D-00 S2 (ATT4D-00 Terminal Interface Module) provides direct physical/electrical execution. It terminates field signals from pressure, flow, and temperature transmitters directly to the system backplane without signal attenuation.

Hardware Specifications

DCS Signal Integrity & Process Control Architecture

• 4-20 mA HART Loop Protocol Pass-Through: Supports transparent bidirectional digital communication superimposed on standard analog current signals, maintaining HART protocol integrity across dual signal paths.
• Channel-to-Channel Electrical Isolation: Prevents ground loop currents and transient voltage spikes from propagating between field instrumentation and the CENTUM I/O processing cards.
• Optimized Cold Junction Compensation (CJC): Accommodates accurate thermocouple voltage conversion by maintaining uniform thermal boundary conditions across all termination points.

Frequently Asked Questions

Q: Can individual terminal wires be disconnected while the system is under live 24 VDC / 4-20 mA power?

A: Yes. The spring-loaded pressure clamp design allows isolated field wire insertion and removal without disrupting adjacent redundant circuit loops or requiring system power-down.

Q: What is the impact on signal transmission during a failover between the dual-redundant signal paths?

A: Signal transfer between the redundant paths is instantaneous and passive, resulting in zero transfer lag or interruption to the 4-20 mA analog signal or HART digital overlay.

Field Installation Guidelines

Ensure the DIN rail or specialized baseplate is properly grounded to the industrial earth grid before mounting the assembly. Strip field wiring to exact length (8 mm to 10 mm) without nicking conductors. Insert wires firmly into the spring-loaded pressure clamps until seated. Maintain a minimum separation of 50 mm between low-voltage signal wiring and high-voltage power distribution lines to prevent electromagnetic interference. Verify that field cable shielding is grounded at a single point according to system engineering specifications.