The Allen-Bradley 1756-AMXN is a specialized communication module engineered for the ControlLogix platform to facilitate seamless integration between modern controllers and legacy industrial networks. This module acts as a bridge, enabling ControlLogix systems to communicate with Reliance Electric AutoMax Distributed Power Systems (DCS) and traditional Allen-Bradley Remote I/O (RIO) networks. It provides a strategic migration path for brownfield sites, allowing operators to modernize their control architecture while retaining functional legacy drive racks and remote I/O infrastructure.
Features
High-Performance Processing: Equipped with a 100 MHz IDT MIPS processor for efficient protocol translation and data handling.
Memory Architecture: Features 1 MB of onboard logic RAM and 512 KB of shared backplane RAM to manage complex communication tasks.
Versatile Operating Modes: Supports DCS Master, DCS Slave, and RIO Master configurations for flexible network deployment.
Legacy Network Compatibility: Bridges the gap between ControlLogix backplanes and AutoMax DCS or RIO environments.
High-Capacity Communication: Capable of managing up to 55 DCS slave nodes in Master mode or handling extensive I/O polling in RIO mode.
Technical Specifications
Brand
Allen-Bradley
Product Line
ControlLogix
Module Type
Communication Interface
Processor
100 MHz IDT MIPS
Memory
1 MB Logic RAM / 512 KB Shared RAM
Backplane Current (5.1V)
650 mA
Backplane Current (24V)
75 mA
Power Dissipation
5 Watts
Interface Port
DB9 D-shell
Node Capacity
55 DCS Slave Nodes (Master Mode)
Installation Guidelines
Ensure the ControlLogix chassis is powered down before inserting or removing the 1756-AMXN module to prevent electrical damage.
Verify that the module is fully seated in the chassis slot and that the retaining screws are tightened to ensure proper grounding.
Use appropriate shielded cabling for the DB9 interface to minimize electromagnetic interference (EMI) in high-noise industrial environments.
Configure the module operating mode through the ControlLogix software environment prior to establishing network communication.
Maintain adequate ventilation around the chassis to ensure heat dissipation stays within the 5W power dissipation limit.
FAQ
Q: Can the 1756-AMXN be used to replace an AutoMax controller entirely? A: Yes, it is designed to allow a ControlLogix controller to act as the master for an existing AutoMax DCS network, effectively replacing the legacy controller while maintaining the existing field devices.
Q: What is the primary function of the RIO Master mode? A: In RIO Master mode, the module acts as a remote scanner, allowing the ControlLogix processor to read and write data to legacy Remote I/O chassis, supporting up to 250 input words and 28 output words.
