Description
The Allen-Bradley 1785-L40B is a high-performance PLC-5/40 programmable controller processor designed to execute complex control algorithms and manage extensive I/O architectures within the PLC-5 chassis environment. This processor is engineered for medium-to-large-scale industrial automation applications requiring robust processing power, deterministic scan times, and versatile communication routing across legacy network infrastructures.
The controller mounts directly into a standard PLC-5 backplane slot and integrates battery-backed static RAM for user program storage, supplemented by an EEPROM program backup option. It features embedded DH+ and Universal Remote I/O interfaces, allowing seamless data exchange, multi-rack expansion up to 61 total I/O chassis, and multi-tier network integration for distributed factory floor automation.
Features
Supports up to 2,048 total digital inputs and 2,048 digital outputs, or a complementary mix
Accommodates up to 2,048 maximum analog I/O points
Equipped with 4 built-in Data Highway Plus (DH+) and Universal Remote I/O communication ports
Configurable RS-232, RS-423, and RS-422A serial communication channel for point-to-point interface
Backplane current draw of 3.3A at 5VDC with a total power dissipation of 17.3W
Operating temperature range of -40 to 85 Celsius (-40 to 185 Fahrenheit)
Applications
Large-scale discrete manufacturing and sequential logic control loops
Distributed rack system management via Universal Remote I/O links
Legacy Data Highway Plus (DH+) network supervisory communication
Process control and analog data acquisition in continuous industrial plants
Technical Specifications
| Parameter |
Specification |
| Manufacturer |
Allen-Bradley / Rockwell Automation |
| Product Type |
PLC-5 Controller Processor |
| Catalog Number |
1785-L40B |
| Series |
PLC-5 / PLC-5/40 |
| Memory Type |
Battery-backed static RAM |
| Maximum Digital I/O Capacity |
2,048 inputs / 2,048 outputs |
| Maximum Analog I/O Capacity |
2,048 analog I/O |
| Communication Ports |
4 DH+ / Remote I/O channels, 1 configurable serial port (RS-232/423/422A) |
| Backplane Current Load |
3.3A at 5VDC |
| Power Dissipation |
17.3W |
| Operating Temperature |
-40 to 85 Celsius (-40 to 185 Fahrenheit) |
| Country of Origin |
United States |
Compliance and Certifications
UL Listed Industrial Control Equipment
CE compliant for applicable directives
C-Tick mark certified