Symbol DS 3408, Product Reference Manual

Page: 29 / 406

Scanning 2 - 7
Aiming
Hold the digital scanner between two and nine inches (depending on symbol density; see Decode Zones on page
2-9 ) from the symbol, centering the aiming pattern cross hairs on the symbol.
The aiming pattern is smaller when the digital scanner is closer to the symbol and larger when it is farther from the
symbol. Scan symbols with smaller bars or elements (mil size) closer to the digital scanner, and those with larger
bars or elements (mil size) farther from the digital scanner.
The digital scanner can also read a bar code presented within the aiming pattern but not centered. The top
examples in
Figure 2-5 show acceptable aiming options, while the bottom examples can not be decoded.
Figure 2-5
Acceptable and Incorrect Aiming
0 1 2 3 4 5
0 1 2 3 4 5
0 1 2 3 4 5
0 1 2 3 4 5
NOTE Scanning Direct Part Marks (DPMs) with the DS3408-DP (DPM) Digital Scanner: Due to the reflective
nature of some surfaces used with DPMs (see
Figure 2-4 on page 2-6 ), the best results for scanning
DPMs with the DS3408-DP (DPM) digital scanner can be achieved by tilting the scanner at an angle
relative to the target. It is recommended that the scanner be titled 25-45 degrees to get the best
performance from the DPM unit when scanning DPMs. As a guide, if you are trying to read a 23 mil dot
peen mark and the scanner is set to the near field focus, you must present the target between one and
four inches from the nose of the scanner at a minimum tilt of 30 degrees.
When scanning standard (non-DPM) bar codes with any configuration of the DS3408 digital scanner,
follow the standard aiming instructions described in
Aiming .