External Level
This mode is effective in an application where the speeds of the conveying apparatus are variable and the time the scanner spends reading each object is not predictable. It also allows the user to determine if a No Read has occurred.
External Level allows the read cycle (active state) to begin when a trigger (change of state) from an external sensing device is received. The read cycle persists until the object moves out of the sensor range and the active trigger state changes again.
Important: Level and Edge apply to the active logic state (Negative or Positive) that exists while the object is in a read cycle, between the rising edge and the falling edge. Rising edge is the trigger signal associated with the appearance of an object. Falling edge is the trigger signal associated with the subsequent disappearance of the object. This applies both to External Level and External Edge.