The Yokogawa SNT511 is an Optical ESB Bus Repeater Slave Module used in Yokogawa ProSafe-RS Safety Instrumented Systems (SIS).
It is designed to work with a master module (SNT401 / SNT411) to extend ESB bus communication over optical fiber, enabling long-distance, high-reliability data transmission between safety controllers, safety nodes, and remote I/O systems.
In ESB network architecture, the SNT511 is always the remote-side (slave) optical interface module.
Technical Specifications
| Parameter | Specification |
|---|---|
| Brand | Yokogawa |
| Model | SNT511 |
| Product Type | Optical ESB Bus Repeater (Slave) |
| System Compatibility | ProSafe-RS / ESB bus architecture |
| Function | Optical signal reception & retransmission |
| Pairing Module | SNT401 / SNT411 (Master side) |
| Network Type | ESB optical fiber communication |
| Topology | Star / Chain connection |
| Max Connection Stages | 2 stages |
| Transmission Distance | Up to 5 km per segment, up to ~50 km total (2-stage system) |
| Current Consumption | ~0.5 A |
| Weight | Approx. 0.3 kg |
| Operating Temperature | -20°C to +70°C (ISA G3 class, typical) |
Physical Characteristics
| Item | Specification |
|---|---|
| Dimensions (W × H × D) | Approx. 32.8 × 130 × 142.5 mm |
| Weight | ~0.3 kg |
| Mounting Type | 19-inch rack / ESB repeater system |
| Structure | Optical slave repeater module |
| Installation | SIS control cabinet |
System Role
The SNT511 acts as the slave-side optical ESB repeater node.
Typical architecture:
-
ESB Bus from controller (SEC401 / SSB401 / SSC system)
→ SNT401 / SNT411 (Master)
→ Optical fiber link
→ SNT511 (Slave)
→ Remote safety node / I/O system
This enables deterministic and noise-immune long-distance communication in safety-critical systems.
Recommended Related Models
- Yokogawa SNT401 / SNT411 – Master optical ESB repeater modules
- Yokogawa SNT501 – alternative slave variant
- Yokogawa SNT10D – rack-mounted ESB repeater unit
- Yokogawa SNB10D – safety node unit
- Yokogawa SEC401 / SEC402 – ESB coupler modules
