Overview
The Allen-Bradley 1785-ENET is a side-car Ethernet interface module designed to add TCP/IP communication capabilities to PLC-5 processors via Channel 3A. This single-slot module attaches directly to series B or later PLC-5 processors and provides a dedicated Ethernet link for messaging, programming, and supervisory communication over industrial networks.
Key Features
- 10/100 Mbps auto-negotiating Ethernet connection via single RJ45 port
- EtherNet/IP protocol support with TCP/IP messaging capability
- Supports up to 64 simultaneous connections and 512 unsolicited message definitions
- Built-in status LEDs for link activity, 100M, and 10M indicators
- Communicates through processor Channel 3A only; does not access 1771 I/O backplane
- Compatible with RSLogix 5, Studio 5000, and legacy programming tools
Technical Specifications
- Module Type: Single-slot Ethernet interface module
- Communication Protocol: EtherNet/IP (TCP/IP)
- Transmission Speed: 10/100 Mbps with auto-negotiation
- Connections: One RJ45 port (8-pin), 64 simultaneous connections per module
- Backplane Current: 2.2 A (module current); 1 A (backplane draw @ 5 VDC)
- Power Dissipation: 5 W / 37.54 BTU/hr
- Operating Temperature: 0 to 60°C (32 to 140°F)
- Storage Temperature: −40 to 85°C (−40 to 185°F)
- Relative Humidity: 5 to 95% non-condensing
- Operating Vibration: 2 G @ 10–500 Hz
- Operating Shock: 30 G peak acceleration, 11±1 ms duration
- Weight: 1.74 lbs
- Mounting: 1771-A1B, -A2B, -A3B, -A3B1, or -A4B chassis, second left-most slot
- Condition: Used / Surplus
Typical Applications
- Distributed I/O system integration over Ethernet networks
- Human Machine Interface (HMI) and visualization system connectivity
- Supervisory Control and Data Acquisition (SCADA) implementations
- Distributed Control System (DCS) peer-to-peer communication
- Remote programming access and online controller management
- Legacy PLC-5 system modernization and network retrofit
Compatibility & Replacements
The 1785-ENET is designed exclusively for PLC-5 series B or later processors and installs as a side-car module on the processor. It is no longer continuously manufactured; however, surplus stock is available through industrial distributors. Common replacement variants include the 1785-ENET/A and 1785-ENET/C for specific hardware revisions. For ControlLogix or CompactLogix systems, use EtherNet/IP modules from the 1756 or 1769 series instead. This module has been tested and verified compatible with RSLogix 5 and Studio 5000 programming environments.
