Allen-Bradley 1785-L40B | PLC5 Programmable Logic Controller

Overview

The 1785-L40B by Allen-Bradley is a high-performance PLC5 Programmable Logic Controller, designed for medium to large industrial automation applications.

It mounts on PLC5 chassis such as 1771-A1B, 1771-A2B, 1771-A3B, 1771-A3B1, and 1771-A4B, providing flexible deployment across multiple racks.

With 48 KWords of user memory, the 1785-L40B supports up to 2048 total I/O points or 2048 inputs and 2048 outputs in complementary configuration.

The controller handles one local rack and up to 28 Remote I/O racks, enabling efficient expansion and large-scale automation integration.

Key Features

• Brand & Model: Allen-Bradley 1785-L40B

• Product Type: PLC5 Programmable Logic Controller

• Processor: PLC-5/40

• Memory: 48 KWords user memory, battery-backed static RAM

• EEPROM Backup: Supported via 1785-ME16, -ME32, -ME64, -M100

• Max Total I/O: 2048 points or 2048 in + 2048 out

• Max I/O per Link: 32

• Embedded Communication Interfaces: 4 DH+/Remote I/O (Adapter or Scanner), 1 serial port configurable for RS-232, 423, and RS-422A

• Backplane Current Load: 3.3A

• Power Dissipation: 17.3 W

• Power Supply Compatibility: 1771-P4S, -P6S, -P4S1, -P6S1

• Control Coprocessor Expansion Port: Yes

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

• Non-Operating Temperature: –40…85°C (–40…185°F)

Technical Specifications Table

Description

The 1785-L40B PLC5 controller is built for reliability and scalability in industrial automation.

It delivers precise control for large-scale applications while supporting high-density I/O configurations.

With battery-backed memory and EEPROM program backup options, the 1785-L40B safeguards critical data during power interruptions.

Embedded communication interfaces allow seamless integration into existing PLC5 networks, ensuring efficient data transfer across multiple racks.

The robust thermal and environmental ratings make the controller suitable for both operational and storage extremes, enhancing longevity and reliability.

FAQ

Q1: Is the Allen-Bradley 1785-L40B original?
A1: Yes, the 1785-L40B is brand new and 100% original from Allen-Bradley.

Q2: How much user memory does it support?
A2: The controller provides 48 KWords of user memory for program and data storage.

Q3: What is the maximum I/O capacity?
A3: Supports up to 2048 total I/O points or 2048 inputs and 2048 outputs in complementary configuration.

Q4: Which communication interfaces are included?
A4: It includes 4 DH+/Remote I/O ports and 1 configurable serial port for RS-232, RS-422A, and 423.

Q5: What is the operating temperature range?
A5: The controller operates between 0°C and 60°C (32°F to 140°F) and stores safely between –40°C and 85°C.