VMI VVS OL82 - Splice Guiding Is Not Working

8.5.2 Splice guiding is not working
Problem:
When using splice guiding the error seen in the material scan exceeds 1 mm, indicating
that the material is not well positioned.
Cause 1:
Conveyor speed is too fast (> 300 mm/s) during material scan, VVS is not able to position
the material well.
Cause 2:
If the Beckhoff BK5120 encoder is not initialized (the run led of this module is blinking
instead of uninterrupted) the module can not send encoder information to the VVS. Due to
the lack of this encoder information VVS is not able to center material using splice guiding.
Cause 3:
If the TX-overflow led is active on the Beckhoff BK5120 module, it indicates that the
Canbus is overloaded. This will result in bad centering, due to encoder values which are
received with a delay in VVS.
Solution:
In order to make use of splice guiding it is essential that the TBM is equipped with an
encoder. In addition it is also essential that the encoder is calibrated. Make sure that the
'Counts Per Meter' has the right value (VVSU SYSTEM tab). Also check the measured
length of the breaker in the material scan. The measured length shown in the material scan
should be similar to the parameter length. If this is not the case, check the encoder
calibration.
Solution 1:
Also make sure that the conveyor speed does not exceed 300 mm/s during the material
scan by the camera. VVS is not able to position the material well when using splice guiding
in combination with a conveyor speed faster than 300 mm/s.
Solution 2:
If the run led is blinking, you will need to restart VVS. After restart, VVS will reset the
BK5120 module and will perform the needed initializations. When VVS startup is finished,
the run led of the BK5120 module should be active and not blinking any more.
Make sure the BK5120 module is not picking up EMP interference. This can be easily
checked, go to the VVSU CALIBRATION tab. The encoder value displayed in this
CALIBRATION tab should not be changing unless the corresponding conveyor is moving.
Solution 3
If the TX-overflow led is active, the number of messages sent by the BK5120 module
should be reduced. This can be accomplished by increasing the 'Encoder inhibit time' in
the VVSConfig.ini file (Encoder inhibit time = VVSConfig value (HEX) × 0.1 ms). Changes
made in the VVSConfig.ini will take effect after restart of VVS.
It should be noted that the best splice guiding is obtained by setting the 'Encoder inhibit
time' to 0 (maximum encoder messages sent as possible).
TROUBLESHOOTING
Guiding problems
8
THINKING FORWARD
VMI Vision System VVS (OL82) VVSX 13.0.12.0, VVSU 3.0.6 / 4 / 2016-07-11 / pd#175592
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