RS485:
Reading Techniques
The view finder projects an aiming beam that should be centered over the bar code, but it can be positioned in any direction for a good read.
Hold the scanner over the bar code, press the button, and center the aiming beam on the bar code.
The aiming beam is smaller when the scanner is closer to the code and larger when it is farther from the code. Hold the scanner close to smaller bar codes, and farther away from large bar codes to get a proper read.