Schneider NW-BM85S485 Modbus Multiplexer Bridge Module

NW-BM85S485 Multiplexer Bridge for Modicon Quantum Networks

Product Introduction

The NW-BM85S485 from Schneider Electric serves as a dedicated multiplexer bridge within the Modicon Quantum automation platform. This module facilitates seamless communication using the Modbus RTU protocol over an RS-485 physical layer. Consequently, it enables efficient data exchange between field devices and the central controller. The unit supports baud rates up to 115.2 kbps, ensuring responsive network performance. Additionally, the NW-BM85S485 employs shielded twisted-pair cabling to maintain signal integrity in electrically noisy environments. Its compact form factor allows for straightforward rack mounting within existing Quantum systems. For applications requiring robust and isolated serial communication, this bridge module offers a dependable solution.

Communication Protocol and Interface

The NW-BM85S485 leverages the widely adopted Modbus RTU protocol, which ensures interoperability with numerous industrial instruments. It communicates over an RS-485 interface, supporting multi-drop network configurations. Specifically, this module incorporates an RJ45 connector for easy cable termination. Furthermore, the unit provides galvanic isolation between the communication ports and the internal circuitry. This isolation protects the host system from ground loop currents and voltage transients. Meanwhile, the module's design accommodates both Modbus Plus and standard RS-485 networks, offering flexible integration options.

The NW-BM85S485 also functions as a bridge, translating between different network types when required. This bridging capability simplifies system architecture by connecting Modbus segments seamlessly. For instance, it can link a Modbus Plus backbone to RS-485 device networks. Therefore, this module reduces the need for additional protocol converters.

Electrical and Power Specifications

Powering the NW-BM85S485 is straightforward, as it accepts a wide input voltage range. It operates on 12 to 24V DC, making it compatible with common industrial power supplies. Remarkably, the module consumes less than 1 watt of power, minimizing heat generation. This energy efficiency contributes to long-term reliability in dense control cabinets. Additionally, the unit's rated supply voltage also covers 115 to 220V AC variants, though the DC version remains standard.

The NW-BM85S485 includes robust signal isolation features. Galvanic isolation ensures that communication remains stable despite potential differences in ground potential. This feature is particularly valuable in large factories with distributed equipment.

Environmental and Mechanical Parameters

The NW-BM85S485 operates effectively across a broad temperature spectrum. Its functional range spans from -20°C to +70°C, accommodating most industrial environments. For storage, it tolerates extremes from -40°C to +85°C without damage. Furthermore, the module supports relative humidity levels between 5% and 95%, non-condensing. This wide humidity tolerance makes it suitable for both dry and damp locations.

The unit carries an IP20 enclosure rating, indicating protection against solid objects larger than 12 mm. Consequently, it is best suited for installation inside protected control panels. Measuring 100 mm in length, 50 mm in width, and 25 mm in height, the NW-BM85S485 occupies minimal rack space. Its lightweight construction of 2.07 kg facilitates easy handling during installation.

Installation and Mounting Guidance

Installing the NW-BM85S485 follows standard Modicon Quantum rack-mounting procedures. First, ensure that the power supply is disconnected before inserting the module. Next, align the module with the designated slot on the Quantum rack. Then, firmly seat the module until the retaining clips engage securely. After mounting, connect the RS-485 network using shielded twisted-pair cable to the RJ45 port. Additionally, verify that terminating resistors are properly configured at both ends of the bus.

For optimal performance, route communication cables away from high-voltage power conductors. Use proper grounding techniques for the cable shield to reduce noise susceptibility. Finally, configure the communication parameters through the Quantum CPU's programming software.

Packaging List

Your shipment of the NW-BM85S485 includes the following items:

• One multiplexer bridge module

• Mounting instructions leaflet

• Connector pinout reference card

Note: Cables, terminating resistors, and mounting hardware are not included.

Shipping Information

All orders are dispatched promptly via trusted global carriers. We utilize Fedex, UPS, and DHL for reliable delivery. Tracking numbers are provided upon shipment.

Frequently Asked Questions (FAQ)

Q1: Is the NW-BM85S485 compatible with Modicon Premium series?
A1: This module is primarily designed for the Modicon Quantum platform. Compatibility with Premium series is not guaranteed.

Q2: What is the maximum cable length supported by the NW-BM85S485?
A2: For RS-485 networks, the maximum cable length depends on baud rate. At 115.2 kbps, lengths up to 1,200 meters are achievable with proper cabling.

Q3: Can the NW-BM85S485 act as a standalone gateway?
A3: It functions as a bridge within the Quantum rack. Standalone gateway operation requires a separate power supply and housing.

Q4: How many devices can the NW-BM85S485 support on its RS-485 network?
A4: It supports up to 32 standard devices without repeaters. Additional devices require signal boosting.

Q5: Does the NW-BM85S485 include LED status indicators?
A5: Yes, the module features diagnostic LEDs for power, communication activity, and fault conditions.