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3Wire RS2S2 | Dual Slave Isolated RS485 Hub
3Wire RS2S2 is a high-performance RS-485 hub designed for environments with complex electromagnetic interference. It extends an existing RS-485 bus into two highly reliable RS-485 output interfaces, making it useful for branch networks, long-distance communication, outdoor installations and industrial control applications. With optoelectronic isolation, 600W surge protection and up to 2,500V isolation, RS2S2 helps improve communication safety, stability and reliability. RS-485 networks are widely used because they are simple, robust and cost-effective. However, long wiring runs, outdoor cabling, branch connections and electromagnetic interference can cause unstable communication. RS2S2 helps strengthen RS-485 communication by providing isolated output branches with surge and ESD protection. It is suitable for industrial automation, metering, remote monitoring, BMS, EMS, access control, alarms and other RS-485 based systems. Extend one existing RS-485 bus into two reliable RS-485 output branches. Improve communication reliability between controllers, meters, sensors and field devices. Use RS2S2 to branch Modbus RTU meter networks for EMS, AMR and IoT gateway applications. Support RS-485 communication expansion for building automation and facility monitoring systems. External SMPS power supply helps reduce common ground interference and improves outdoor suitability. Designed for complex electromagnetic environments where stable RS-485 communication is required. Extends one RS-485 input bus into two output interfaces for reliable branching. Built-in optoisolator provides up to 2,500V RMS isolation for safer communication. Each RS-485 line is protected with 600W lightning and surge protection. Provides strong protection against electrostatic discharge in industrial environments. Automatically detects data flow direction and switches communication direction accordingly. Designed to improve RS-485 communication timing and reduce delay-related issues. RS2S2 can extend an existing RS-485 bus to two highly reliable RS-485 interfaces. For larger systems, multiple RS2S2 hubs can be connected in parallel to expand the RS-485 network into multiple reliable interfaces. The datasheet indicates that a maximum of 128 RS-485 hubs can be connected to the RS-485 bus in parallel, depending on network design and site conditions. 485B: RS-485 - input 485A1: 1ch RS-485 + output 485A2: 2ch RS-485 + output Use RS2S2 when one RS-485 trunk needs to be split into two reliable output branches. Use RS2S2 in noisy industrial areas where optoelectronic isolation and surge protection can improve communication reliability. Use RS2S2 to support RS-485 communication over longer distances, up to 3,000 metres depending on baud rate and site conditions. The following visual supports the RS2S2 dual slave RS-485 hub operation, bus extension and isolated branch interface information above. RS2S2 Dual Slave RS-485 Hub Operation Diagram 3Wire RS2S2 is a dual slave isolated RS-485 hub designed to extend an existing RS-485 bus into two reliable isolated RS-485 output interfaces. With 2,500V RMS isolation, 600W surge protection, ±15kV ESD protection, automatic data direction control, 300 bps to 115.2 kbps baud rate and up to 3,000m transmission distance, RS2S2 is suitable for demanding industrial RS-485 communication networks. Contact 3Wire / Saturn Pyro for product selection, wiring support and RS-485 network application guidance.Extend One RS-485 Bus into Two Reliable Isolated Interfaces
Industrial RS-485 hub for noisy, long-distance and outdoor communication environments.
Why RS2S2?
Typical Applications
RS-485 Bus Extension
Industrial Automation
Energy and Metering Systems
BMS and Facility Systems
Outdoor Applications
High EMI Environments
Key Features
Dual Slave RS-485 Output
Optoelectronic Isolation
600W Surge Protection
±15kV ESD Protection
Automatic Direction Control
RS-485 Time Delay Support
RS-485 Network Expansion
Interface Definition
Input Side — 4-Pin Terminal
485A: RS-485 + input
V-: Power ground
V+: 9–40VDC inputOutput Channel 1
485B1: 1ch RS-485 - output
GND: Isolated ground wireOutput Channel 2
485B2: 2ch RS-485 - output
GND: Isolated ground wireTechnical Highlights
Parameter
RS2S2 Specification
Product Type
Dual slave isolated RS-485 hub
Standards
RS-485, EIA / TIA compliant
RS-485 Input
4-pin terminal block
RS-485 Output
6-pin terminal block with two RS-485 output channels
Transmission Media
Twisted-pair or shielded cable
Communication Mode
Asynchronous half-duplex
Power Supply
9–40V DC, 500mA
Indicators
LED indicators for Power (PWR), Transmit (TXD) and Receive (RXD)
Isolation Voltage
2,500V RMS; 500V DC with DC/DC isolation module
Baud Rate
300 bps to 115.2 kbps
Protection Features
600W lightning and surge protection per RS-485 line; ±15kV ESD protection
Transmission Distance
0 to 3,000 metres, dependent on baud rate
Parallel Hub Expansion
Up to 128 RS-485 hubs can be connected to the RS-485 bus in parallel, subject to network design
Dimensions
80 × 50 × 31 mm
Operating Temperature
–40°C to +85°C
Relative Humidity
5% to 95%, non-condensing
Where RS2S2 Fits
When You Need RS-485 Branching
When EMI Is a Concern
When Distance Is Long
RS2S2 Operation Diagram
Product Summary