Rockwell Automation 2755 Enhanced Decoder Series B - Manual (Page 288)

17–6 Maintenance and Troubleshooting
Publication 2755-833
Solution: Calculate ”scans per label” based on line speed and bar
code orientation (picket fence or step ladder). Calculate at least
five scans per label at full line speed. If calculation is less than
five scans per label, select a higher speed scanner or reduce
product line speed.
Problem: Output LED indicator does not operate.
Cause: Configuration parameters are not set correctly.
Solution: Review configuration parameters. The LED indicators
are active for the duration set by the output duration parameter. If
a duration is set to 0000, the LED will not change (although the
counters still increment). After making corrections, we
recommend you, SAVE the changes and RESTART the decoder.
Cause: Outputs disabled.
Solution: Restart decoder.
Problem: Output LED indicator operates but output does not.
Cause: Improper connections.
Solution: Check connections to output modules. Verify that
power is present. Check polarity of DC modules.
Cause: Output module fuse blown.
Solution: Determine reason for blown fuse, correct problem, and
then replace fuse.
Cause: Defective output module.
Solution: Replace defective module with new module.
Problem: Output module fuse 77104-899-01 blows.
Cause: Inductive device used with module has an inrush current
that exceeds module specifications.
Solution: Replace the fuse and use a device rated within the
specification.
Problem: Output module (Catalog No. 2755-OB5S) blows.
Cause: Excessive back EMF of inductive load.
Solution: Install a rectifier diode in parallel with the module. See
Appendix G.