Panasonic LP-400 Series External Control Manual page 147

„Moving objects
Troubles
Marking cannot be done.
Marking is sometimes
skipped.
(E800 occurs.)
Characters unreadable
Marking position is
unstable.
Marking character pitch
is unstable.
Character is partially
chipped.
Actual spacing between
characters is larger or
small than setting.
Causes
Encoder signal is off.
Marking trigger signal is entered before
current marking is finished.
Feed direction is not correct.
Speed changes at conveyor junction.
Actual speed and preset speed for
feeding objects are different due to
slippage of objects.
Pulse setting of encoder is not correct.
Encoder is out of order.
Positional misalignment is likely to
occur due to meandering motion of
conveyor.
The line speed at the marking position
is different from the speed at the
installation site of the encoder.
Obstacle hinders laser beam.
Pulse setting of encoder is not correct.
Either A or B phase signal is refused. (A
and B phase used)
Measured number of encoder pulses
differs from calculated one.
ME-LP400V-EX-6
Measures
Check for proper connection to encoder.
• Increase scan speed setting of laser marker.
• Decrease delay distance setting of laser
marker.
• Reduce feeder speed.
• Increase marking interval (interval between
objects on feeder).
Match feed direction with laser marker operation.
If conveyors are coupled, avoid marking near
conveyor junction.
Remove cause of object slippage.
Measure the number of encoder pulses and
adjust "Number of encoder pulses".
Check encoder for proper function.
Secure objects to prevent misalignment.
Place the encoder as close as possible to the
marking position.
Decrease the encoder resolution to block the
effect of the line speed fluctuation.
Note that the minimum value of the encoder pulse
should be 10 P/mm.
Remove obstacle between head of laser marker
and object.
Check setting to be sure that:
• When using A phase only:
Number encoder pulses = Number of pulses/
mm x 2
• When using A and B phases:
Number encoder pulses = Number of pulses/
mm x 4
Check that signal is applied to A and B phase
terminals of encoder.
Increase or decrease values in "Encoder fine
adjustment" field as appropriate.
• When the character interval is wide:
Increase the setting.
• When the character interval is narrow:
Decrease the setting.
147