The SB311 S1 is an ESB Bus Interface Master Module used in Yokogawa DCS architectures to manage communications across an internal system bus called the

 ESB (Extended Serial Backboard). It typically replaces standard bus interface cards for enhanced functionality,

particularly in systems requiring event logging/synchronization.

Frequently Asked Questions

Q1. What system bus does SB311 use?

The SB311 uses the Extended Serial Backboard (ESB bus), which is a Yokogawa internal communication bus for I/O and node interface within a control station.

Q2. Is the SB311 S1 a redundant module?

SB311 modules can be used in duplexed (redundant) configurations depending on system design, though the specific implementation

depends on your Yokogawa system setup and model variants. Redundancy usually requires a paired module for fail‑over support.

Q3. What interfaces are available on the SB311?

Typical interfaces include:

• Ethernet port (10Base‑T) for SOE data or communication to servers.

• RS‑422 serial interface for receiving external time codes like IRIG‑B.