Allen Bradley’s 803-B124R unit is classified as a Rotating Cam Limit Switch from the 803 series. This device has already been implemented in many applications with precise repetitive control tasks like steel forming units, injection molding machines, and punching presses. The shaft of the 803-B124 rotating cam limit switch is coupled mechanically to the target machine. When a movement of the targeted machine is expressed through cam limit switch shaft rotation, the 803-B124R actuates its contacts and an electrical signal is further processed. This is a flexible device, as it enables operation with both clockwise and counterclockwise rotating directions, and is designed for installation in any plane. The 803-B124R has a “style B” designed housing. It is a bulletin 803 product with the highest possible number of separate control circuits, the total being twelve. These are 10 A rated 1 NO - 1 NC snap action contacts. They have an A600 NEMA rating designation with a type of enclosure that is a 4 & 13 watertight, dust-tight, and oil-tight industrial enclosure. It has a built-in speed reducer with a 20:1 gear ratio. As seen from the front of the device, the shaft extension is located on the left side.

The 803-B124R rotating cam limit switch has the following integral parts: a strong steel base surrounded by iron side plates, a 0.75 inch diameter shaft with oversized ball bearings, cam segment assemblies (rotated for dwell time adjustment and then fixed with nuts) vibration resistance, single pole double throw snap action contacts (10A rated), and cable glands on each side. The Allen-Bradley 803-B124R has the following dimensions (shaft not included): 541.3 millimeters x 568.3 millimeters x 173.0 millimeters (21.31 inches x 22.38 inches x 6.81 inches). The device weighs 28.1 kilograms (62 pounds) with an operating temperature range of -30 to 66 degrees Celsius (-22 to 150 degrees Fahrenheit). This rotating cam limit switch has officially been out of production since 2007.