The 803-F812P6X switch by Allen Bradley is a Bulletin 803 rotating cam limit switch. This device works by the principle of direct movement transmission from a machine to the axis or shaft of the device through a chain drive or a belt. While the axis/shaft rotates, this device’s eight cam assemblies mounted on the shaft are rotating as well. On user-defined angular positions, found in the timing parameter, these cam operators actuate control contacts (10A, 1NO / 1NC, snap action contacts with NEMA rating designation A600) for an adjusted period of time in the dwell parameter. In this way, a feedback signal is sent to a PLC or some other logic control electronic device intended for process control.

The 803-F812P6X is a “Style F” rotating cam limit switch that has externally adjustable timing and dwell parameters. The adjustment of these parameters is conducted with a screwdriver. Cam durations are settable in the range of 12 to 348 degrees. The 803-F812P6X has six internally adjustable cam modifications. This option is available for use exclusively on the 803-F812P6X “style F” rotating cam limit switch. All of this module’s six internally adjustable cams should only be adjusted when this module’s shaft is in its idle state. The extension type on this bulletin 803 device is a double shaft extension. The Allen-Bradley 803-F812P6X has a shipping weight of 6.4 kilograms (14 pounds) and its dimensions with the double shaft extension excluded are 312.7 x 82.6 x 177.8 millimeters (or 12.31 x. 3.25 x 7.00 inches). The 803-F812P6X has a working temperature range of -22 to 150 degrees Fahrenheit (-30 to 66 degrees Celsius). Allen-Bradley has not produced this module since 2007 when production of the device was stopped.