SEC402-21 | Yokogawa | ESB Bus Coupler Module

Yokogawa SEC402-21 ESB Bus Coupler Module

The Yokogawa SEC402-21, also cataloged as the SEC402 ESB bus coupler module, serves as a dual-port master interface for connecting ProSafe-RS safety control units to distributed ESB bus I/O node assemblies.

Hardware Specifications

Channel-to-Channel Isolation

The SEC402-21 maintains deterministic ESB bus communication with channel-to-channel isolation across redundant node connections. Dual-port architecture allows flexible distribution of up to 13 I/O nodes, while shielding and impedance control in YCB301 cabling suppress cross-talk. Redundant installation in SSC60□ or S2SC70□ units ensures fail-safe synchronization in ProSafe-RS safety architectures.

Frequently Asked Questions

Q: Can both ports be fully loaded with 9 nodes each? A: No, while each port supports up to 9 nodes, the combined total must not exceed 13 nodes.

Q: What is the recommended cable for ESB bus connections? A: The SEC402-21 requires Yokogawa YCB301 ESB bus cables to maintain impedance and shielding specifications.

Q: How is redundancy achieved in installation? A: Modules are typically installed in pairs within SSC60□ or S2SC70□ safety control units to support dual-redundant ESB bus operation.

Field Installation Guidelines

• Install the module in designated slots within SSC60□ or S2SC70□ safety control units.
• Use only Yokogawa YCB301 ESB bus cables to ensure proper impedance and shielding.
• Maintain cable length ≤10 m per port to avoid signal degradation.
• Verify connector seating and strain relief before energizing the system.
• Route ESB bus cabling away from high-voltage conductors to minimize induced noise.
• Confirm redundant module pairing for fail-safe operation.