Allen-Bradley 1756-L61 ControlLogix CPU Processor Module

The Allen-Bradley 1756-L61 ControlLogix CPU Processor Module is a 5561-series controller that serves as the central processing unit for ControlLogix racks, delivering reliable, high-speed logic execution for complex automation tasks. It provides 2 MB of user memory and 478 KB of I/O memory, with optional nonvolatile storage via a CompactFlash card to preserve data between power cycles. This CPU is designed for use within the ControlLogix 5561 family and installs into a 1756 backplane, enabling scalable control of sequential, process, and motion-related applications when paired with appropriate I/O and networking modules. Typical electrical characteristics include a backplane current of about 1.20 A at 5 V and a power dissipation around 3.5 W, with a weight near 0.71 lb (0.32 kg). In practice, the 1756-L61 supports multi-tasking and large program structures, making it suitable for moderate-to-large automation environments that rely on the ControlLogix ecosystem for centralized control, data logging, and integration with other Rockwell Automation components.