Product Overview

The Allen-Bradley 1785-ENET/C is a high-performance Ethernet communication expansion module, commonly referred to as a "sidecar," designed to upgrade PLC-5® controller systems with modern networking capabilities. By attaching directly to the side of a PLC-5 processor, this module provides a dedicated Ethernet/IP port, allowing legacy hardware to bridge the gap to contemporary plant-floor networks. This integration enables the processor to exchange data with HMI/SCADA systems, remote programming workstations, and other PLC platforms over standard TCP/IP protocols.

The 1785-ENET/C is essential for facilities looking to modernize their data acquisition and monitoring without replacing the entire control infrastructure. It effectively transforms a standard PLC-5 into a networked node capable of peer-to-peer messaging and global data sharing, extending the operational utility of the PLC-5 platform.

Network Integration and Configuration

The module functions by adding a logical channel to the controller architecture, designated as Channel 3A.

• Communication Versatility: Supports EtherNet/IP for real-time data exchange and TCP/IP for standard messaging and diagnostics.

• Flexible Addressing: IP addresses can be assigned manually via programming software (such as RSLogix 5) or dynamically using BOOTP/DHCP utility tools.

• Controller Compatibility: Specifically engineered for use with ControlNet 1.5 PLC-5 processors, including the enhanced series of controllers.

• Diagnostic Monitoring: Requires the configuration of a dedicated integer diagnostic file within the PLC logic to track communication health, packet loss, and connection status.

• Software Synchronization: Offline configuration requires precise channel mapping to ensure that the physical hardware is recognized immediately upon being brought online.

Technical Specifications

• Manufacturer: Allen-Bradley (Rockwell Automation)

• Model Number: 1785-ENET/C

• Module Type: Ethernet/IP Interface Sidecar

• Communication Port: 10 Mbps Ethernet (AUI or RJ45 depending on transceiver)

• Logical Channel: Channel 3A

• Power Requirements: 2.2A @ 5V DC (supplied via the processor connection)

• Maximum Connections: Supports up to 16 simultaneous TCP/IP sessions

• Operating Temperature: 0°C to 60°C (32°F to 140°F)

• Storage Temperature: -40°C to 85°C (-40°F to 185°F)

• Relative Humidity: 5% to 95% (Non-condensing)

• Dimensions: 3.5 x 13.0 x 14.5 cm

• Weight: 0.9 kg (1.98 lbs)

Operational Reliability and Hardware Requirements

The 1785-ENET/C is designed to thrive in industrial environments while maintaining high-speed data throughput.

• Firmware Requirements: The host PLC-5 processor must be updated to a compatible firmware revision to recognize the sidecar hardware and the 3A communication channel.

• Physical Installation: The module must be securely latched to the left side of the processor before power is applied to the chassis to prevent electrical arcing or data corruption.

• Ruggedized Architecture: Built with the same industrial tolerances as the 1771 I/O system, providing resistance to electromagnetic interference (EMI) and vibration.

• Legacy Protection: Provides a cost-effective pathway to Industry 4.0 by enabling Ethernet connectivity on hardware that predates modern networking standards.