| Button/Symbol | Official Function (from ZYX-J30 manual) | Hidden / Secondary Function | |---|---|---| | ON/OFF | Power on/off | Reset if frozen (hold 10 sec) | | MODE | Switch units (g/oz/ct/gn) | Lock a unit (hold 3 sec) | | ZERO | Zero display | Exit calibration early | | TARE | Subtract container weight | Show gross weight (hold) | | CAL | Begin calibration | Show internal temperature (some models) | | PCS | Piece counting mode | Enter sample size (10, 20, 50 pcs) |