Product Overview

The Allen-Bradley 1756-L63/B is a ControlLogix Logix5563 programmable automation controller, representing the Series B revision of the widely deployed 1756-L63 processor. As the central processing unit of a ControlLogix chassis, the 1756-L63/B executes user programs, manages I/O communication, and coordinates controller-to-controller messaging across industrial networks. The Series B designation distinguishes this unit from the original Series A 1756-L63, bringing hardware refinements and requiring firmware revision 13.40 or later for proper operation . The 1756-L63/B occupies a single slot in any standard ControlLogix chassis, including the 1756-A4, A7, A10, A13, and A17 models, and draws 1.2A at 5.1V DC and 14 mA at 24V DC from the backplane .

The 1756-L63/B provides 8 MB of user memory and 478 KB of dedicated I/O memory, a capacity that supports complex control strategies involving extensive tag databases, add-on instructions, and coordinated motion applications . The processor handles up to 32 tasks with 100 programs per task, allowing engineers to partition control logic by function, update rate, or equipment zone. A single built-in RS-232 serial port supports ASCII, DF1 full/half-duplex, DF1 radio modem, DH-485, and Modbus protocols via logic, providing direct connectivity to legacy devices, modems, and operator interfaces without additional communication modules .

Within the broader Logix5000 family, the 1756-L63/B supports the full range of programming languages—ladder logic, structured text, function block diagram, and sequential function chart—and accommodates communication adapters for EtherNet/IP, ControlNet, DeviceNet, Data Highway Plus, Remote I/O, SynchLink, and third-party networks . The processor supports full redundancy configurations for high-availability applications and integrated motion via SERCOS interface or CIP Motion over EtherNet/IP. For facilities maintaining legacy ControlLogix infrastructure, the 1756-L63/B remains a critical spare, particularly where Series A controllers have been upgraded or where Series B hardware was specified from the outset.

Technical Specifications