A saw comprising: a saw blade for cutting a workpiece supported by a frame of the saw; a motor coupled to the saw blade, the motor having an on condition to move the saw blade for cutting the workpiece and an off condition in which the saw blade is not moved; a table top defining an opening and including a work surface, the work surface configured to support the workpiece for movement along the table top toward the opening; a blade guard removably disposed above the opening; a saw blade carriage configured to support the saw blade with respect to the table top, the saw blade carriage being located on one side of the work surface and the workpiece being located on another side of the work surface; a workpiece detection system (130, 600, 700) configured to detect the workpiece, the workpiece detection system (130, 600, 700) including an emitter/detector fixedly coupled to one of the frame of the saw and the saw blade carriage, wherein the emitter/detector is located on one side of the work surface and the workpiece is located on another side of the work surface and is configured to transmit a beam through the opening and toward the workpiece, to detect one of the presence of a reflected signal from the workpiece indicative of the height of the workpiece and the absence of the reflected signal from the workpiece, and to transmit a workpiece height signal indicative of the detected one of the presence and absence of reflected signal from the workpiece; a processing unit operatively coupled to the emitter/detector; and a relay operatively coupled between the processing unit and the motor, wherein the processing unit is configured to provide a relay signal to the relay in response to at least the workpiece height signal, and wherein the relay signal is configured to control movement of the saw blade; wherein the saw further comprises a blade guard sensor configured to provide a blade guard sensor signal indicative of one of a presence and an absence of the blade guard above the opening, wherein the processing unit is configured to provide the relay signal in response to the workpiece height signal and the blade guard sensor signal such that the processing unit turns off the motor when the blade guard is present and the height of the workpiece is higher than the lowest portion of the blade guard. a saw blade for cutting a workpiece supported by a frame of the saw; a motor coupled to the saw blade, the motor having an on condition to move the saw blade for cutting the workpiece and an off condition in which the saw blade is not moved; a table top defining an opening and including a work surface, the work surface configured to support the workpiece for movement along the table top toward the opening; a blade guard removably disposed above the opening; a saw blade carriage configured to support the saw blade with respect to the table top, the saw blade carriage being located on one side of the work surface and the workpiece being located on another side of the work surface; a workpiece detection system (130, 600, 700) configured to detect the workpiece, the workpiece detection system (130, 600, 700) including an emitter/detector fixedly coupled to one of the frame of the saw and the saw blade carriage, wherein the emitter/detector is located on one side of the work surface and the workpiece is located on another side of the work surface and is configured to transmit a beam through the opening and toward the workpiece, to detect one of the presence of a reflected signal from the workpiece indicative of the height of the workpiece and the absence of the reflected signal from the workpiece, and to transmit a workpiece height signal indicative of the detected one of the presence and absence of reflected signal from the workpiece; a processing unit operatively coupled to the emitter/detector; and a relay operatively coupled between the processing unit and the motor, wherein the processing unit is configured to provide a relay signal to the relay in response to at least the workpiece height signal, and wherein the relay signal is configured to control movement of the saw blade; wherein the saw further comprises a blade guard sensor configured to provide a blade guard sensor signal indicative of one of a presence and an absence of the blade guard above the opening, wherein the processing unit is configured to provide the relay signal in response to the workpiece height signal and the blade guard sensor signal such that the processing unit turns off the motor when the blade guard is present and the height of the workpiece is higher than the lowest portion of the blade guard.