Overview
The Allen-Bradley 1772-LP2 /A is a PLC-2/20 central processing unit developed by Rockwell Automation for mid-range industrial automation and machine control applications. This Series A programmable controller offers 8064 words of program/data memory and supports up to 896 I/O devices, making it suitable for legacy system maintenance, upgrades, and replacement scenarios. Operating across 120–240V AC in environments from 0–60°C, it remains a proven solution for controlling manufacturing processes, conveyor systems, and sequential automation tasks.
Key Features
- 8064 words of CMOS read/write memory for flexible program and data storage with on-line editing capability
- Up to 896 I/O support compatible with diverse input/output device types (solenoids, motors, sensors, solid-state relays)
- 4-position mode select switch for Run, Test, Idle, and Remote modes
- Visual status indicators on front panel for quick fault diagnosis and troubleshooting
- Data Highway compatible for networking and inter-processor communication
- Arithmetic, timing, counting, and I/O forcing operations built into instruction set
Technical Specifications
Key electrical and physical parameters:
- Input Voltage: 120–240V AC
- Frequency: 50/60 Hz
- Memory: 8064 words
- I/O Capacity: Up to 896 I/O
- Operating Temperature: 0–60°C
- Humidity: 5–95% (non-condensing)
- Weight: 37 pounds
- Backup Battery: Lithium cell (3.6V, LS33600-BA compatible)
Typical Applications
The 1772-LP2 /A excels in retrofit and maintenance scenarios:
- Legacy manufacturing equipment control and process automation
- Conveyor and material handling system management
- Sequential logic and interlock control
- Machine tool and press control systems
- Food processing and packaging equipment
- Wastewater treatment and industrial pump stations
Compatibility & Replacements
The 1772-LP2 /A is a direct replacement for original 1772-LP2 units in same-configuration installations. It integrates with standard Allen-Bradley I/O modules, power supplies, and communication interfaces from the 1772 product family (including the 1772-LH Processor Interface Module and 1772-P1 Power Supply). Technicians should verify memory and I/O configuration requirements before substitution. This Series A controller is no longer actively supported by Rockwell Automation; consult documentation and local integrators for firmware and software compatibility with modern programming tools.
