Overview
The Allen-Bradley 1785-L11B /C is a PLC-5/11 standard processor module designed for classic industrial automation systems requiring reliable, distributed control. The processor is a PLC 5 series standard processor that delivers proven performance in manufacturing, process control, and facility automation applications. The 1785-L11B has 8000 words of user memory space, supporting program complexity appropriate for mid-range control systems. RAM of the controller has battery backup, ensuring program retention during power loss.
Key Features
- 8000 words of user memory for program and data storage
- Works with up to 512 total I/O points in the same system
- Built-in port for Data Highway Plus (DH+) or Remote I/O
- Programs can be saved, restored and edited while operating
- EEPROM program backup option can be installed in front panel situated slot
- Rated backplane current load of 2.3 Amps at 5 Volts
Technical Specifications
- Memory: 8K of built-in memory
- Maximum I/O Points: 512 any mix (local and remote combined)
- Maximum Analog I/O: 512
- Backplane Current: 2.3 A at 5 Volts
- Power Dissipation: About 12 Watts under normal operating circumstances
- Communication: 1 built-in port for Data Highway Plus (DH+) or Remote I/O
- I/O Expansion: Can utilize a total of 5 I/O chassis, with 4 being universal remote I/O chassis
- Series: C
- Condition: Used
Typical Applications
Interconnects I/O modules both local, extended and remote, devices on various type of communication interfaces and creates one control system suited for needs associated with controlling the processes. Typical uses include:
- Manufacturing equipment control and sequencing
- Process automation in chemical, food, and beverage industries
- Material handling and conveyor systems
- Facility automation and HVAC control
- Legacy PLC-5 system upgrades and maintenance
Compatibility & Replacements
The 1785-L11B /C is part of the classic PLC-5 family and operates within 1785-series chassis-based systems. As part of the PLC-5 family, the 1785-L11B supports modular I/O expansion, communication via Data Highway Plus (DH+), and advanced control features. Series variants (A, B, C, D, E) share the same form factor and basic functionality; compatibility is chassis-dependent. For modern replacements, consider Rockwell CompactLogix or ControlLogix platforms, though direct plug-in replacement is not available. This processor pairs with standard 1771-series I/O modules and 1785-series expansion chassis.
