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3Wire RS2M2 | Dual Master Isolated RS485 Hub
3Wire RS2M2 is a 2-channel isolated RS-485 hub that allows two RS-485 master devices to communicate with one or more RS-485 slave devices without cross-interference. It ensures that responses from slave devices are sent only to the corresponding master that initiated the request, improving communication control in multi-master RS-485 environments. Some sites require two master devices, such as a PLC and monitoring system, to access the same RS-485 slave network. Without proper isolation and communication control, multi-master communication can create collision, interference and unreliable responses. It is useful where the same RS-485 device network must be shared between control, monitoring, automation, metering or supervisory systems. Allow PLCs, controllers and monitoring systems to access RS-485 slave devices with better communication separation. Supports master-slave protocols such as Modbus for industrial metering and control systems. Share RS-485 digital power meters between automation systems and energy monitoring platforms. Useful where BMS, EMS or SCADA systems need access to the same RS-485 slave device network. Suitable for RS-485 based alarm systems, access control networks and site monitoring systems. Supports RS-485 communication sharing for remote monitoring and control applications. Allows two RS-485 master devices to communicate with one or more slave devices. Responses from slave devices are sent only to the master that initiated the request. Each communication port can be configured independently for baud rate and communication format. Provides robust signal integrity and helps protect communication circuits from electrical disturbance. Includes 15kV ESD protection and 5kA lightning surge protection for industrial RS-485 environments. DC 9–30V input with built-in overcurrent and reverse polarity protection. RS2M2 includes three RS-485 communication interfaces for controlled dual-master access to a shared slave network. RS-485 Master 1 interface for the first master device. RS-485 Master 2 interface for the second master device. RS-485 slave interface for one or more connected slave devices. Connect VCC to the positive terminal of the DC 9–30V power supply and GND to the negative terminal. Connect terminal A to the RS-485 A line, terminal B to the RS-485 B line, and GND to signal ground where required. The SET terminal / button is used for configuration setting as part of the RS2M2 interface arrangement. The following visual supports the RS2M2 dual master RS-485 hub operation, shared slave network and controlled response routing information above. RS2M2 Dual Master RS-485 Hub Operation Diagram 3Wire RS2M2 is a dual master isolated RS-485 hub designed to allow two RS-485 master devices to communicate with one or more slave devices while reducing cross-interference. With photoelectric isolation, 15kV ESD protection, 5kA lightning surge protection, independent port configuration, transparent transmission and DC 9–30V power input, RS2M2 is suitable for industrial automation, metering, access control, alarms and remote monitoring applications. Contact 3Wire / Saturn Pyro for product selection, wiring support and RS-485 communication application guidance.Two RS-485 Masters. One Slave Network. No Cross-Interference.
Industrial RS-485 hub for Modbus and master-slave communication systems.
Why RS2M2?
Typical Applications
Industrial Automation
Modbus RTU Networks
Energy Management
BMS and Facility Systems
Alarm and Access Control
Remote Monitoring
Key Features and Protection
Dual RS-485 Master Support
Controlled Response Routing
Independent Port Configuration
Photoelectric Isolation
ESD and Surge Protection
Power Protection
Communication Interface
MA1
MA2
SLA
Technical Highlights
Parameter
RS2M2 Specification
Product Type
Dual master isolated RS-485 hub
Master Interfaces
MA1 and MA2 for RS-485 master devices
Slave Interface
SLA for RS-485 slave devices
Communication Type
Master-slave protocols, including Modbus and similar protocols
Data Transmission
Transparent transmission
Baud Rate
1200 bps to 115200 bps; default 9600 bps
Communication Format
Stop bit, bit length and parity can be configured
Slave Node Capacity
Slave port supports up to 175 nodes depending on network conditions
Protection Level
RS-485 interface protection with 600W surge protection and ±15kV ESD protection
Electrical Isolation
Communication and power isolation; master and slave interface isolation
Power Input
DC 9–30V
Minimum Required Current
≥100mA
Maximum Voltage Limit
Do not exceed 35V
Power Protection
Built-in reverse polarity protection and overcurrent protection
Processor Architecture
32-bit microcontroller with high-speed optocouplers
Status Indicators
LED indicators for communication ports and status monitoring
Wiring and Power Summary
Power Input
RS-485 Wiring
SET Button
RS2M2 Operation Diagram
Product Summary