Overview
Manuals
Primary Applications
Real-World Usage Considerations
Features:
- I/O chassis designed for efficient integration within the PLC 5 series
- This unit features a maximum capacity for four I/O racks utilizing 1/2-slot addressing
- Enabling firm organization of input and output modules
The Allen Bradley 1771-A4B I/O chassis is designed for robust performance in PLC 5 system architectures. Equipped with 16 slots, it accommodates a variety of modular components required for various applications. Notably, it manages up to four I/O racks and utilizes half-slot addressing for optimal space utilization. Installing this chassis requires 36 plastic clamps to ensure a secure mounting.
This chassis is compatible with a variety of processors, particularly those rated between 2 and 4 amps with integrated power supplies. Power modules rated between 3 and 8 amps can also be used. The external power supply rated for this chassis must be between 6.5 and 16 amps. Furthermore, the leftmost slot is dedicated to the processor module and I/O adapter module. Communication and I/O modules can be installed in any slot, but not in the leftmost slot; the same applies to the power supply module. All these features make the 1771-A4B an indispensable and flexible component in high-performance industrial environments.
The 1771-A4B Allen Bradley 16 Slot I/O Chassis may still be available for purchase and support from Moore Automated Company beyond End-Of-Life (EOL) by the manufacturer (OEM).
Allen Bradley 1771-A4B 16 Slot I/O Chassis Manuals(Datasheets), Link
Important Notice: Other accessories, manuals, cables, calibration data, software, etc. are not included with this equipment unless listed in the above stock item description. All prices are shown in USD.
Central Control Center: Serving as the main processor chassis for large-scale factory automation systems, the leftmost slot accommodates a local PLC-5 processor (e.g., PLC-5/40 or PLC-5/80) and can simultaneously hold up to 15 digital, analog, or dedicated I/O modules.
High-Density Remote I/O (RIO) Expansion: Deployed in large production workshops as a remote expansion rack. By installing a 1771-ASB RIO adapter module or a 1771-ACN ControlNet adapter in the first slot, this rack can act as a distributed I/O center and connect to the main PLC via "blue pipe" or ControlNet.
Heavy-Duty Manufacturing: Widely used in harsh, high-vibration environments such as automotive assembly, oil and gas processing, pulp and paper mills, and wastewater treatment infrastructure.
Enclosure Requirements: Sold in an "open" enclosure. Its panel must be mounted in an industrial electrical cabinet that meets NEMA Class 2 pollution standards.
Power Independence: To operate all 16 slots under peak load, it relies on a separate external power supply (e.g., 1771-P4S or 1771-P7) connected via jumper connectors configured in the enclosure.
Relocation Target: As the 1771-A4B is an obsolete hardware series, many existing plants utilize its physical dimensions to plan for the 1492 rotary arm migration kit, allowing technicians to directly reconnect the 1771 rack to the modern ControlLogix 5580 enclosure without altering field wiring terminals.
