A cam based control uses a rotary cam limit switch to give the press control reference points of the rotation of the press. Cam based controls do not have real time brake monitors but use an overrun proximity to check the brake. Only use a cam based control if you already have a time based brake monitor or if your press is guarded to prevent hands in the die/pinch area.
In the majority of applications resolver based press controls are desired. Among the many other benefits, CIECO resolver based controls provide an integral time based brake monitor and eliminate the need for a rotary cam limit switch.