Rockwell Automation 2755 Enhanced Decoder Series B - Manual (Page 287)

17–5 Maintenance and Troubleshooting
Publication 2755-833
Solution: Determine the optimum reading angle by using a static
bar code label position and checking the Decoder Performance
Indicators with the Decode Mode set to Continuous. Fix the
scanner at a position that produces a high decoder performance
value. After properly positioning the scanner, return the decoder
configuration to the correct triggered mode of operation.
Cause: Scanner lens is incorrect for the label size.
Solution: Select a scanner with a lens appropriate for the label
size. Refer to scanner User Manual.
Cause: Label out of specification.
Solution: Use labels that are within industry standards.
Problem: Excessive ”No-Reads” during decoding.
Cause: Poor or marginal quality bar code labels.
Solution: Use labels that meet Automatic Identification
Manufacturer’s (AIM) specifications for the selected symbology.
Cause: Incorrect scanner selected for application.
Solution: Measure narrow bar width (or space, whichever is
narrowest) of bar code and note minimum and maximum reading
distance. Consult your scanner’s User Manual to verify that these
specifications are within the proper guidelines for your scanner.
Cause: Scanner is at incorrect angle or distance from the bar
code.
Solution: Determine the optimum reading angle by checking the
Decoder Performance Indicators while the Decode Mode is set to
Continuous and using a static bar code label position. Fix the
scanner at a position that produces a high decoder performance
value. After properly positioning the scanner, return the decoder
configuration to the correct triggered mode of operation.
Cause: Package detect positioning.
Solution: Make sure the package detect signal is active before
the bar code enters the laser beam. Check that package detect is
continually blocked while in scanning area of laser. The ”Trigger
Active” indicator should light when a bar code is scanned in
triggered mode.
Cause: Scan speed not high enough or product line speed to
high.