Allen-Bradley 1747-L551 SLC 500 Processor Module

Allen-Bradley 1747-L551 SLC 500 Processor Module is the SLC 5/05 CPU for the SLC 500 modular controller family. It provides 16,000 words of user memory and supports a large I/O address space, with capability for up to 4,096 input points and 4,096 outputs, enabling mid-range automation tasks. The CPU includes Ethernet connectivity for networked control and RS-232 serial communication for programming and device links. Typical program and I/O performance figures place program scan around 0.9 milliseconds and I/O scan around 0.225 milliseconds, depending on configuration and load. Non-volatile storage is handled by Flash EPROM, ensuring firmware and user program retention across power cycles. This processor is used in industrial applications such as conveyors, batch handling, mixing, and other discrete/analog control tasks where a compact, reliable CPU is required within a modular SLC 500 rack. It remains compatible with standard SLC 500 I/O modules and supports common networking and serial devices, making it suitable for legacy systems needing upgrade or integration with Ethernet networks.