Systems and methods for use with a handheld mark reader that reduce the time between activation of the reader’s trigger and the reader returning a successful decode response. The controlled release nature of the table prevents the accumulation of orally effective amounts of opioid antagonist when taken normally. The back cover defines a back microphone cavity at an end thereof, corresponding in position to that of the front microphone cavity in the front cover. A dummy stack ring is formed around the memory array. A controller is operable to obtain the detection signal at a plurality of positions in the first region to determine a threshold value of the detection signal for detecting whether the target medium exists on the platen.