Description

Yokogawa SNT501-13 Optical ESB Bus Repeater Slave Module

The Yokogawa SNT501-13, also cataloged as the SNT501 Optical ESB Bus Repeater Slave Module, operates as a dedicated hardware component for ESB bus optical signal transmission within Yokogawa ESB Bus communication networks. The module converts electrical ESB bus signals to optical signals for fiber-optic communication when installed with a corresponding optical repeater master module.

Suffix Breakdown & Model Matrix

Model Element	Description
SNT501	Optical ESB Bus Repeater Slave Module
-1	Standard specification
3	ISA Standard G3 conformal coating

Hardware Specifications

Parameter	Specification
Model	SNT501-13
Brand	Yokogawa
Product Type	Optical ESB Bus Repeater Slave Module
Function	ESB Bus optical transport
Connection Method	Star type, Chain type
Maximum Connecting Stages	2 stages
Transmission Distance	Up to 5 km (two stages total)
Extended Transmission Distance	Up to 10 km with Vnet/IP R1.03 or later
Optical Attenuation Requirement	3 - 4 dB attenuator required when fiber attenuation is less than 3 dB
Power Consumption	0.5 A
Weight	Approx. 0.3 kg
Dimensions	Approx. 3.2 cm x 12.7 cm x 12.7 cm
Operating Temp	-20 degC to +60 degC
Humidity	5 % to 95 % RH, non-condensing
Origin	Japan

Channel Isolation and Fiber-Optic Communication Characteristics

Within Yokogawa DCS and safety communication architectures, optical transmission provides galvanic isolation between connected ESB bus segments. The fiber-optic interface reduces susceptibility to conducted electrical noise present on metallic communication paths. Installation requires verification of optical path attenuation; where total fiber attenuation remains below 3 dB, an external 3 - 4 dB attenuator should be inserted to prevent optical receiver saturation.

Frequently Asked Questions

Q: Does the SNT501-13 support direct electrical ESB bus extension without optical fiber?
A: No. The module is intended for optical transmission of ESB bus signals and is designed to operate with fiber-optic communication links.

Q: What is the maximum number of repeater stages supported?
A: The specification permits a maximum of two connecting stages within the optical ESB bus repeater network.

Q: Is additional optical attenuation sometimes required?
A: Yes. If installed fiber attenuation is less than 3 dB, a 3 - 4 dB optical attenuator should be placed between modules according to the specified transmission requirements.

Field Installation Guidelines

1. Verify fiber-optic connector cleanliness before module commissioning.
2. Confirm optical attenuation values throughout the complete transmission path prior to energization.
3. Route optical cables separately from high-voltage power conductors where practical.
4. Observe minimum fiber bend-radius requirements specified by the cable manufacturer.
5. Confirm compatibility of connected master and slave optical repeater modules before network startup.
6. Ensure cabinet environmental conditions remain within the specified temperature and humidity limits.
7. Inspect grounding and shielding practices of associated ESB bus equipment according to site engineering standards.

Specifications

• Brand: Yokogawa

Advantages

• High reliability in industrial environments
• Supports continuous operation
• Compatible with major PLC/DCS systems