Product Description

The SED4D-01 is a high-integrity digital relay terminal board designed for the Yokogawa ProSafe-RS safety architecture.

This module functions as a secure field-side digital output interface, connecting safety control units (SCUs) or safety node units (SNUs) to external safety actuators and signaling devices.

The SED4D-01 provides 8 independent output channels using Form A (Normally Open) relay contacts, enabling reliable switching of industrial loads while maintaining strong electrical isolation between the safety controller and field equipment.

Key design features include:

• Galvanic isolation for safety signal protection

• High load switching capability for industrial actuators

• Ruggedized construction for harsh environments

• Compatibility with Emergency Shutdown (ESD) and Fire & Gas (F&G) systems

The module is commonly installed in Remote Instrument Enclosures (RIEs) or field auxiliary control rooms.

Technical Specifications

Application and Safety Use

The SED4D-01 is commonly used in:

• Hydrocarbon processing facilities

• Offshore oil and gas platforms

• Power generation safety systems

• Maritime safety control systems

It is typically paired with digital output control modules to drive:

• Solenoid valves

• Motor starters

• Alarm indicators

• Safety shutdown actuators

Because relay outputs can handle higher voltage and current loads compared to semiconductor outputs, this module is ideal for final element control in safety loops.

Technical FAQ

What type of relay contacts does the SED4D-01 use?
The module uses Form A (Normally Open) relay contacts, which support fail-safe operation. In the absence of control power or signal, the relay returns to an open state, helping maintain safe system conditions.

Can the SED4D-01 be used in non-safety applications?
While possible, this module is specifically designed and certified for use within ProSafe-RS safety systems. Using it in certified safety loops helps maintain compliance with SIL (Safety Integrity Level) requirements.