Allen Bradley 1785-L40E | PLC-5/40E EtherNet/IP Controller Module

Product Description

The Allen Bradley 1785-L40E is a PLC-5/40E processor module designed for Ethernet/IP communication and advanced control applications. Although discontinued by the manufacturer, it remains a robust solution for legacy systems requiring high-capacity memory, multiple communication interfaces, and reliable performance in industrial automation environments.

Technical Specifications

• Manufacturer: Allen Bradley

• Category: PLCs

• Product Line: PLC-5

• Part Number: 1785-L40E

• Processor Type: PLC-5/40E Ethernet processor

• User Memory: 48 KWords SRAM

• Communication Ports: 1 Ethernet, 2 DH+/Remote I/O, 1 RS-232/422A/423 serial

• Backplane Current Draw: 3.3 A

• Power Dissipation: 17.3 W

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

• Storage Temperature: −40–85 °C (−40–185 °F)

• Maximum I/O Capacity: 2048 mixed or 2048 in + 2048 out complementary

• I/O Scan Time per Rack: 10 ms @ 57.6 kbit/s; 7 ms @ 115.2 kbit/s; 3 ms @ 230.4 kbit/s

• Serial Ports: RS-232-C / RS-422A / 423 supported

• Battery: 1770-XYC

• EEPROM Backup: Supported with 1785-ME16/ME32/ME64/M100 modules

• Maximum I/O Chassis (Total): 61

• Maximum I/O Chassis (Universal Remote): 60

• Maximum I/O Chassis (Extended Local): 0

• Weight: 3.00 lbs (1.36 kg)

• Compatible Power Supplies: 1771-P4S, 1771-P6S, 1771-P4S1, 1771-P6S1

Application Scenarios

• Legacy PLC-5 systems requiring Ethernet/IP connectivity

• Large-scale process control with high I/O capacity

• Industrial automation environments needing multiple communication protocols

FAQ

Q: Is the 1785-L40E still in production?  A: No, it has been discontinued. Replacement options include ControlLogix processors.

Q: What is the maximum number of I/O chassis supported?  A: Up to 61 chassis in total, with 60 universal remote chassis.

Q: Does the module support EEPROM backup?  A: Yes, with compatible EEPROM modules (1785-ME16/ME32/ME64/M100).

Comparison with Similar Models

• 1785-L40E: Ethernet-enabled PLC-5/40 processor, 48 KWords memory

• 1785-L20E: Lower memory capacity, fewer I/O options

• 1785-L80E: Higher-end PLC-5 processor with expanded memory and I/O support