The Allen-Bradley 1785-L20B is a PLC-5/20 programmable logic controller (PLC) processor designed for medium to large-scale industrial automation applications. With 16K words of user memory, Data Highway Plus (DH+), RS-232-C/422-A/423-A communication ports, and support for up to 512 I/O points, this processor provides fast execution times, extensive networking options, and high system reliability. The PLC-5 series is widely used in manufacturing, process control, and distributed industrial automation systems.
Technical Specifications
- Manufacturer: Allen-Bradley (Rockwell Automation)
- Model: 1785-L20B
- Series: PLC-5/20
- User Memory: 16K Words (Battery-backed SRAM)
- EEPROM Program Backup Compatibility: 1785-ME16, -ME32, -ME64, -M100
- Total I/O Capacity: 512 points (any mix of inputs/outputs)
- Maximum Analog I/O: 512 points
- I/O Scan Time per Rack:
- 10 ms @ 57.6 kbps
- 7 ms @ 115.2 kbps
- 3 ms @ 230.4 kbps
- Communication Ports:
- 1 Data Highway Plus (DH+)
- 1 DH+/Remote I/O (Adapter or Scanner Mode)
- 1 RS-232-C/422-A/423-A Configurable Serial Port
- Maximum I/O Chassis Supported: 13
- Backplane Current Load: 3.3 A @ 5V DC
- Mounting Type: 1771 I/O Chassis (left-most slot)
- Programming Software: RSLogix 5
- Operating Temperature: 0°C to 60°C (32°F to 140°F)
Key Features
- High-speed processing for efficient execution of control logic
- Supports multiple communication protocols for seamless integration into industrial networks
- Expandable memory via EEPROM backup modules for program storage and recovery
- Modular design for easy integration into 1771 I/O chassis
- Remote I/O capability for distributed automation architectures
- Reliable performance in industrial automation systems
Compatible Allen-Bradley Components
- Allen-Bradley 1771 I/O Modules (Digital, Analog, Specialty I/O)
- Allen-Bradley DH+ and Remote I/O Networks
- FactoryTalk View HMI Software for real-time system monitoring
- RSLogix 5 Programming Software
- Allen-Bradley Power Supplies (1771 Series)
Industry Applications
- Manufacturing and assembly automation
- Process control in oil, gas, and chemical industries
- Power generation and distribution control systems
- Material handling and conveyor automation
- Water and wastewater treatment plants
Installation & Operational Notes
- Installs in the left-most slot of a 1771 I/O chassis
- Ensure proper power supply compatibility for reliable operation
- Use RSLogix 5 software for configuration, programming, and troubleshooting
- Supports scheduled and unscheduled communication for flexible control architectures
- Routine firmware updates and maintenance recommended for optimal system performance
We ship this product nation wide! Delivery is normally stock.
Request a Quote now or call us at 1-800-755-2883 for expert assistance.
This item is Brand New. We are unauthorized by Allen Bradley.