SNT501-53 Optical Repeater – ESB Bus Slave, Star/Chain | Yokogawa

Product at a Glance

• SNT501-53 – optical ESB bus repeater slave module from Yokogawa
• Converts ESB bus signals to optical for long‑distance transmission
• Extends ESB bus up to 5 km (10 km with Vnet/IP R1.03+)
• Supports both star and chain connections
• Compact and lightweight – only 0.3 kg
• Low power consumption – 0.5 A
• Wide temperature range: -20…70 °C (maintenance purpose)
• No explosion protection (suffix 5), ISA G3 compliant (suffix 3)

Key Features

• Extends ESB bus distance – up to 5 km per stage
• Two connection types – star or chain topology
• Up to two stages – flexible system design
• Works with SNT401 – master‑slave repeater pair
• ISA G3 compliant – suitable for harsh environments
• No terminator needed – plug‑and‑play operation

Technical Specifications

• Brand – Yokogawa
• Model – SNT501-53
• Series – ESB Bus Repeater
• Type – Optical slave repeater module
• Function – ESB bus optical transport
• Connection – star or chain type
• Max stages – 2
• Max distance – 5 km per stage (10 km total for Vnet/IP R1.03+)
• Current consumption – 0.5 A
• Weight – approx. 0.3 kg
• Temperature – -20…70 °C
• Protection – no explosion protection (suffix 5)
• Environmental – ISA Standard G3 (suffix 3)

Installation & Setup

• Mount – install in Yokogawa rack or DIN rail
• Connection – fiber optic cable between SNT401 (master) and SNT501 (slave)
• Wiring – use ESB bus cable to connect to SSB401 or SEC401
• Topology – choose star or chain based on system layout
• Power – supply 5 V DC (0.5 A) from rack
• Check – verify fiber cable length before power‑up

Maintenance & Diagnostics

• Status LED – indicates power and communication health
• No configuration – plug‑and‑play, no software setup
• Cleaning – use dry cloth; avoid solvents
• Fiber inspection – check connectors for dirt or damage
• Replacement – hot‑swap not supported; power off before removal

Compatibility

• Master side – SNT401 optical ESB bus repeater master module
• Controllers – safety control units with SEC401/SEC402 couplers
• Node units – safety node unit SNB10D with SSB401 interface
• N‑IO nodes – compatible with N‑ESB Bus Module S2EN501
• Fiber cable – standard optical fiber (multimode or single‑mode)

Certifications & Standards

• ISA G3 – compliant with harsh environment standard
• CE – European conformity
• RoHS – compliant
• Temperature range – -20…70 °C (maintenance purpose)

Package Contents

• 1× SNT501-53 optical repeater slave module
• Quick start guide (paper)
• Warranty registration card

Warranty & Delivery

• 12‑month warranty – covers manufacturing defects
• 12‑24 hour dispatch – ships within one business day
• Carriers – FedEx, UPS, DHL (tracking provided)
• Free technical support via phone/email

Expert Review

• Extends system reach – critical for distributed plants
• Simple to deploy – no software configuration needed
• Flexible topology – star or chain fits any layout
• Rugged design – ISA G3 ensures reliability in harsh areas

Manager’s Insight

• Best for – large process plants with remote I/O nodes
• Saves cost – use fiber instead of expensive copper cables
• Reduces downtime – simple replacement with minimal tools
• Future‑ready – supports Vnet/IP R1.03 for 10 km total distance

Typical Applications

• Oil and gas refineries
• Chemical plants
• Power generation facilities
• Water treatment plants
• Large‑scale distributed control systems (DCS)

Frequently Asked Questions

• What is the SNT501‑53 used for?
• It extends the ESB bus distance using optical fiber in a Yokogawa DCS.
• Can I connect more than two repeaters in series?
• No. Maximum two stages are supported for signal quality.
• What is the maximum distance with two stages?
• 5 km per stage, total 10 km with Vnet/IP R1.03 or later.
• Do I need a terminator?
• No. This module does not require a terminator.
• Is this module explosion‑proof?
• No. Suffix “5” means no explosion protection.
• What does ISA G3 mean?
• It means the module can operate in harsh environments with high temperature and corrosion.
• Can I use this module with other brands?
• No. It is designed specifically for Yokogawa ESB bus systems.
• How do I know if the fiber link is working?
• Check the status LED on the module – green means normal operation.

Selection Guide

• Distance – choose this module if your ESB bus exceeds 1 km.
• Topology – star for centralized layout; chain for linear systems.
• Environment – suffix 3 (G3) for harsh areas; suffix 5 for standard.
• Master module – always pair with SNT401 master repeater.
• System version – check if Vnet/IP R1.03+ for 10 km support.

Comparison with Similar Models

• SNT401 – master repeater module (pair with SNT501)
• SNT501-53 – slave repeater, G3, -20…70 °C (this model)
• SNT501-55 – slave repeater, standard temp, no G3
• S2EN501 – N‑ESB Bus Module for N‑IO nodes

Contact & Support

• Email: sales@powergearx.com
• WhatsApp: +86 18030005825
• Technical support available 24/5

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