Yokogawa CNB-IIA DCS Interface Module

Configured for data acquisition and signal processing in CENTUM CS 3000 networks, the Yokogawa CNB-IIA (CNB-IIA DCS Interface Module) provides direct physical/electrical execution.

Hardware Specifications

Process Control Signal Integration and Isolation Architecture

• Executes high-integrity data acquisition and protocol conversion between field-side instrumentation and central processing logic units across DCS bus structures.
• Integrates channel-to-channel isolation hardware to isolate processing circuits from earth loop currents, common-mode noise, and transient field voltage spikes.
• Supports transparent pass-through for 4-20 mA HART loop protocol parameters across connected analog field device communication paths.

Frequently Asked Questions

Q: What primary communication interfaces are supported on the CNB-IIA interface module?

A: The module supports Ethernet and RS-485 serial communication protocols, depending on the specific hardware backplane configuration.

Q: How does the CNB-IIA module protect signal channels from ground loop interference?

A: Internal channel-to-channel isolation circuitry decouples field-side signal paths from the logic processing bus, preventing circulating currents.

Q: What power input voltage is required for operating the CNB-IIA interface assembly?

A: The module operates on a standard industrial supply rating of 24 VDC.

Field Installation Guidelines

• Secure the module into the designated rack or panel enclosure slot, ensuring side lock levers fully engage the mounting frame.
• Ground all communication and field wiring cable shields to a single dedicated point on the cabinet low-impedance earth bar.
• Maintain physical isolation between high-voltage power lines and low-voltage signal/communication cables within panel wire ducts.
• Verify that ambient airflow around the module remains unblocked to ensure passive thermal dissipation within the -10 to 55 deg C operating limit.