The Allen-Bradley 1785-L40E/E, also cataloged as the PLC-5/40E EtherNet/IP Controller, operates as a dedicated hardware component for programmable logic execution and network communication within the Allen-Bradley PLC-5 control platform.

Model Identification

The 1785-L40E/E is a PLC-5/40E processor module with integrated Ethernet communication capability. It provides SRAM memory storage, processor execution functions, and multiple communication interfaces including Ethernet, Data Highway Plus (DH+), Remote I/O, and serial communication ports.

Hardware Specifications

Industrial Network and Control Features

The 1785-L40E/E integrates Ethernet communication into the PLC-5 architecture, allowing processor-level data exchange through industrial Ethernet networks. The controller maintains compatibility with DH+ and Remote I/O networks for connection with existing Allen-Bradley automation equipment.

For Allen-Bradley PLC platforms, communication interface scaling depends on network architecture, node configuration, and connected I/O devices. The processor provides deterministic control execution through the PLC-5 operating environment while supporting legacy communication protocols.

The module follows Allen-Bradley industrial control firmware compatibility requirements. System upgrades, replacement processors, and communication configuration changes must be verified against the installed PLC-5 hardware revision and application software.

Ordering Information

• 1 x Allen-Bradley 1785-L40E/E PLC-5/40E EtherNet/IP Controller
• Controller type: PLC-5 processor module
• Memory: 48 K Word SRAM
• Integrated communication interfaces:
  • 1 x Ethernet port
  • 2 x DH+/Remote I/O channels
  • 1 x RS-232-C / RS-422A / RS-423A serial port

Field Installation Guidelines

• Install the processor module in a compatible PLC-5 chassis configuration.
• Remove system power before inserting or removing the processor.
• Verify communication addressing before connecting Ethernet, DH+, or Remote I/O networks.
• Use shielded and properly grounded communication cables in industrial environments.
• Separate communication wiring from high-voltage power conductors.
• Confirm processor firmware and programming software compatibility before system commissioning.

Frequently Asked Questions

• What controller family does the 1785-L40E/E belong to?

The 1785-L40E/E is a PLC-5/40E processor module designed for the Allen-Bradley PLC-5 controller family.

• What memory capacity is available in this processor?

The processor contains 48 K Words of SRAM memory for user application storage and controller operation.

• Does the module support Ethernet communication?

Yes. The 1785-L40E/E includes one Ethernet communication interface for network connectivity.

• Which legacy communication networks are supported?

The controller supports DH+ and Remote I/O communication through two dedicated communication ports.

• What serial communication interfaces are available?

The processor provides one serial port supporting RS-232-C, RS-422A, and RS-423A communication standards.

• Can the processor be replaced while the chassis is powered?

The module should not be inserted or removed from an energized chassis. Follow PLC-5 installation procedures and remove power before replacement.

• Is the 1785-L40E/E compatible with modern Ethernet networks?

The module provides Ethernet communication within the PLC-5 architecture. Network compatibility depends on system design and communication configuration.

• Does the processor require firmware compatibility checking?

Yes. Firmware revision compatibility should be verified when integrating the processor into an existing PLC-5 application.