Allen-Bradley 1747-L20E Programmable Controller

Allen-Bradley 1747-L20E is a fixed-hardware SLC 500 controller built for compact discrete automation tasks. It offers 1K words of program memory and a total of 20 I/O points: 12 digital inputs and 8 transistor-output channels. The 12 inputs are 24 VDC sinking, while the 8 outputs are transistor source, rated for 10–50 VDC at up to 0.5 A per channel. Power is supplied from 120/240 VAC, and DH-485 communication enables networked control with other SLC 500 devices. The model includes a high-speed counter input for fast counting operations, making it suitable for simple sequencing, timing, and event counting on small manufacturing lines. Typical applications include packaging, labeling, conveyor control, and small automated pick-and-place tasks where a compact, fixed I/O controller provides straightforward ladder logic and reliable operation.