Allen-Bradley 1756-L61 ControlLogix CPU Processor

The Allen-Bradley 1756-L61 ControlLogix CPU Processor is a high-performance Logix5561 controller module designed to serve as the central processing unit in ControlLogix systems, handling complex sequential, process, and motion control tasks with robust I/O management. It provides 2 MB of user memory for program logic and data, with fixed memory configurations available in 2, 4, or 8 MB and non-volatile storage via a CompactFlash card (1784-CF128) to retain programs and data across power cycles. Weighing about 0.71 lb (0.32 kg), the module draws 1.2 A at 5 V DC and 14 mA at 24 V DC on the backplane, with typical power dissipation around 3.5 W. For communications, the L61 supports EtherNet/IP, ControlNet, DeviceNet, Data Highway Plus, and remote I/O networks, plus a built-in RS-232 serial port offering ASCII, DF1 full/half-duplex, and Modbus via RS232, enabling flexible integration with legacy devices. It can address up to 128,000 I/O points across configured networks, and offers integrated motion capabilities (including SERCOS interface and encoder/SSI options) in suitable configurations for multi-axis automation. Memory retention during power loss is supported via optional batteries (1756-BA1 or 1756-BATM). This CPU is intended for use as the primary controller in a ControlLogix chassis, delivering scalable performance for complex automation applications, from process control to high-speed I/O and motion control.