Allen-Bradley 1756-DNB ControlLogix DeviceNet Communication Bridge Module

Product Overview

The Allen-Bradley 1756-DNB functions as the primary communication bridge between a ControlLogix chassis and a DeviceNet network. This scanner module enables a ControlLogix processor to control I/O, configure devices, and collect data from up to 64 DeviceNet nodes. It manages complex messaging and deterministic data transfers across the factory floor, acting as a vital gateway for motor starters, sensors, and actuators. We supply this module in 100% Brand New condition, ensuring total network stability and long-term compatibility for your integrated architecture.

Technical Specifications

• Network Protocol: DeviceNet

• Max. Number of Nodes: 64 Nodes

• Communication Rates: 125 Kbps (500m), 250 Kbps (250m), 500 Kbps (100m)

• Backplane Current (5.1V DC): 400 mA

• Backplane Current (24V DC): 0 mA

• DeviceNet Voltage: 11–25V DC

• DeviceNet Current Draw (24V DC): 60 mA

• Module Power Dissipation: 3.5 Watts

• USB Interface: 1 Port (12 Mbps speed)

• Slot Width: 1 Slot

• Weight: 0.56 lbs (0.26 kg)

Engineering Advantages

The 1756-DNB streamlines industrial networking through specialized bridging and diagnostic features:

• High-Density Node Management: A single 1756-DNB manages up to 64 independent nodes. This high capacity allows engineers to centralize control of extensive sensor arrays and motor control centers within a single ControlLogix rack, reducing the total hardware footprint.

• Deterministic Data Bridging: The module executes a "producer/consumer" model for data exchange. This ensures that time-critical control data receives priority over the network, maintaining the precise synchronization required for high-speed conveyor systems and assembly lines.

• Simplified Field Commissioning: The integrated 12 Mbps USB port provides a direct point of access for system configuration. Engineers connect their workstations directly to the module to upload or download network schedules via RSNetWorx for DeviceNet, bypassing the need for separate network adapters.

• Efficient Energy Profile: The module draws zero current from the chassis 24V supply, utilizing only the 5.1V backplane power. This reduces the load on the primary chassis power supply and minimizes thermal dissipation within the enclosure, extending the life of adjacent modules.

FAQs

• How do I configure the baud rate for the 1756-DNB?

  The module supports 125, 250, and 500 Kbps. You typically set the baud rate using RSNetWorx for DeviceNet software. Ensure all nodes on the network match the scanner's rate to prevent communication time-outs and network errors.

• Does this module require external power for the DeviceNet port?

  Yes. DeviceNet requires an external 24V DC power supply (connected via the linear bus) to power the physical layer of the network and the communication circuitry of the 1756-DNB port. The module draws approximately 60 mA from this external source.

• Is this a Brand New original product?

  Yes. We guarantee this 1756-DNB is 100% Brand New original stock. In high-speed networking, using brand-new modules is essential to ensure the internal transceivers and USB interface meet original factory specifications for signal integrity.

• Can I install multiple 1756-DNB modules in one chassis?

  Yes. You can install multiple scanners in a single ControlLogix chassis to manage separate DeviceNet segments. Each module functions independently and consumes only one slot.