Allen-Bradley

Allen-Bradley 1785-L40B PLC-5/40 Controller Processor

SKU 1785-L40B

In stock
  • 12-month warranty
  • Free returns within 30 days

  • Manufacturer: Allen-Bradley

  • Product No.: 1785-L40B

  • Country of origin:United States

  • Product Type: PLC Controller Processor

  • Payment: T/T, Western Union

  • Weight: 950g

  • Dimensions: 25.4 x 15.2 x 5.1 cm

  • Shipping port: Xiamen

  • Warranty: 12 months

Overview

The Allen-Bradley 1785-L40B is a PLC-5/40 programmable controller in the Enhanced PLC-5 family. It uses the 1771 chassis architecture and supports legacy PLC-5 communication and I/O systems.

Controller and Memory

  • Catalog number: 1785-L40B
  • Controller family: Enhanced PLC-5
  • Backplane current requirement: 3.3 A at 5 VDC
  • Program memory: Battery-backed memory with compatible optional memory modules

Memory Module Compatibility

Rockwell documentation lists the 1785-L40B with 1785-ME16, 1785-ME32, 1785-ME64, and 1785-M100 memory-module combinations, subject to controller series and revision.

Check the processor series, firmware revision, and installed memory module before replacing or transferring a PLC-5/40 processor.

Firmware Identification

Rockwell's PLC-5 flash documentation identifies firmware by processor series and revision. The product label should be checked before firmware work or repair exchange.

FAQ

What is the maximum I/O capacity of the Allen-Bradley 1785-L40B?
The 1785-L40B supports up to 2,048 digital inputs and 2,048 digital outputs (or a complementary mix), along with up to 2,048 maximum analog I/O points across the control system.

What communication ports are built into the 1785-L40B processor?
The controller includes four DH+ / Universal Remote I/O channels that can function as adapters or scanners, plus one serial communication channel configurable for RS-232, RS-423, and RS-422A standards.

How is user memory retained on the PLC-5/40 processor?
User memory is stored on battery-backed static RAM, with an optional EEPROM module available for program backup and non-volatile storage.

What chassis power is required for this controller?
The 1785-L40B draws 3.3A of backplane current from the 5VDC power supply and generates a total power dissipation of 17.3W.

View all FAQs →

1785-L40B
Quantity
Call sales Contact
Shipping & Returns

Global Express Shipping

  • Standard Delivery: 4–6 business days via DHL, FedEx, and UPS.
  • Express Dispatch: Same-day dispatch for in-stock orders placed before 2:00 PM (GMT+8).
  • Worldwide Coverage: Serving over 150 countries.

Returns & Warranty

  • 30-Day Guarantee: Returns accepted for in-stock products in original, factory-sealed packaging.
  • 12-Month Warranty: Every industrial component is backed by our technical warranty.
Reviews

More from this brand

Allen-Bradley 1746-IO8 SLC 500 Combination Input and Output Module
1746-IO8Allen-Bradley 1746-IO8 SLC 500 Combination Input and Output Module
Allen-Bradley 1746-BAS SLC 500 BASIC Module
1746-BASAllen-Bradley 1746-BAS SLC 500 BASIC Module
Allen-Bradley 1769-OW8 CompactLogix Relay Output Module
1769-OW8Allen-Bradley 1769-OW8 CompactLogix Relay Output Module
Allen-Bradley 1771-IA PLC-5 Discrete Input Module
1771-IAAllen-Bradley 1771-IA PLC-5 Discrete Input Module
  • 1785-L40B
1 1
Only 12 item(s) left in stock
View full details
Product Description
Shipping Returns
Additional details
Reviews

Global Express Shipping

  • Standard Delivery: 4-6 Business Days via DHL, FedEx, and UPS.
  • Express Dispatch: Same-day dispatch for in-stock orders placed before 2:00 PM (GMT+8).
  • Worldwide Coverage: Serving over 150 countries, including rapid delivery to Saudi Arabia and UAE.

Returns & Warranty

  • 30-Day Guarantee: Returns accepted for in-stock products in original, factory-sealed packaging.
  • 12-Month Warranty: Every industrial component is backed by our professional technical warranty.

Orders are processed and delivered Monday-Friday (excluding public holidays).


For full eligibility, restocking fees, and international return details, please view our official Refund & Return Policy .

TECHNICAL SPECIFICATIONS

Country of origin
United States

Technical knowledge

Beckhoff EPP2008-0001 eight-channel EtherCAT P digital output box

Troubleshooting Beckhoff EPP2008-0001 Output Faults

A field checklist for EPP2008-0001 current limits, supply voltage, channel LEDs, connector coding and load-related output faults.

Beckhoff C9900-L100 USB license key for TwinCAT 3.1

Moving TwinCAT 3 Licenses with C9900-L100: Build and Device Checks

Before moving a TwinCAT 3 license with a Beckhoff C9900-L100, verify the TwinCAT build, XML device description, exact order code and cabinet limits.

Beckhoff EL4032 two-channel ±10 V EtherCAT analog output terminal

Replacing a Beckhoff EL4032: Wiring and Output Checks

A field checklist for replacing a Beckhoff EL4032, covering the ±10 V load, terminal map, power contacts, EtherCAT state, and watchdog behavior.

Yokogawa AAI835-S03 analog I/O module for replacement checks

Replacing Yokogawa AAI835: Wiring and Barrier Checks Before Swap

Before replacing a Yokogawa AAI835, verify the 4-in/4-out channel map, power-loss loop behavior, barrier type, output load, cable, and redundancy.

ABB PM891K01 3BSE053241R1 AC 800M processor unit

ABB PM891K01 Replacement: Check Redundancy Before Ordering

ABB PM891K01 article 3BSE053241R1 is the non-redundant AC 800M processor kit. Use this field checklist before replacement.

ABB TP853 3BSE018126R1 module termination baseplate

ABB TP853 Replacement Checks for CI853/CI855/CI857/CI861

Replacement checks for ABB TP853 3BSE018126R1: identify the installed CI853, CI855, CI857, or CI861 interface, record wiring, and verify communication after installation.