Technical Support Services - Allen-Bradley 2755-LS7-SB User Manual

Technical Support Services

Problem Probable Cause (s)
1. Triggering/timeout out of
sync.
2. Object detector or
Decode rate okay
another reader
but getting only no
interfering with reads.
read messages in
triggered mode
3. Window dirty or
obstructed.
1. Reader configured in
Previous label
Continuous Read 1
read, but
Output.
subsequent label subsequent label
will not read. 2. Reader in polled mode.
1. Proper trigger levels not
Reader not
enabled.
entering read
2. Trigger circuit not
cycle in triggered
correctly wired.
mode (trigger not
3. Object detector
working)
inoperative.
"Bad bar code" 1. Poor bar code quality or
message incorrect label position.
"No bar code" 1. No label is present.
message
"No object" 1. No object is present.
message
If you have any questions about the AtomScan
please consult this manual first. If you can't find the answer, contact
Rockwell Automation International Support:
Rockwell International
Technical Support
6680 Beta Drive
Mayfield Village, Ohio 36849
Inside USA and Canada, call 1–800–289–2279.
Outside USA and Canada, contact your Allen-Bradley office or call
USA (216) 646–6800.
Maintenance and Troubleshooting
Corrective Action
1. Review triggering and timing.
2. Remount, eliminate interference, or shielding.
(Many object detectors emit pulsed infrared
signals that can seriously degrade the decode
rate if they shine into the reader or onto the
bar code label when it is being read.)
3. Clean or remove obstruction.
1. Scan a label that contains different data than
that of the one being read.
2. Check communications protocol.
1. Ensure that the trigger pulse and the trigger
polarity settings are correct.
2. Ensure that the trigger circuit wiring meets the
reader requirements.
3. Check detector range and sensitivity. Try a
detector that is known to be good.
1. Reposition label or test with a label that is
known to be good.
1. Scan an object with a bar code on it.
1. Scan an object with a bar code on it.
+
7–3
Bar Code Reader,
Publication 2755-6.9