Specifications

PROPRIETARY DATA: This document contains proprietary data of ABB Inc. No disclosure, distribution (electronic or otherwise),
or other means of dissemination may be made without written permission.
3BUS 208 000 R130190 Platform Tuning
Notes about LHEOS and LFEOS
(Scanning Measurement Limits)
The variables LHEOS and LFEOS define the sheet’s measure limits at the maximum
possible trim positions of the process. This then defines the farthest positions which
the measurement heads can achieve during scanning operations. As a result these
variables define the width and location of all system databoxes.
On multi-frame applications, all frames must be identically aligned with respect to
the physical process. Since sheet shrinkage is a very nonlinear function, it is not
recommended that any attempt be made to compensate for shrinkage by misaligning
the frames. Proper compensation for sheet shrinkage can only be accomplished via
algorithmic means. See Figure 5-13.
Figure 5-13 Limits for Multiple Platform Installations
Procedure for LHEOS and LFEOS
1. Determine the physical center line of the process relative to the Headbox at
each frame location. Note that the center line of the rolls in any area of the
machine may not be the center line of the process.
2. The maximum trim locations should be determined by measuring equal
distances from the center line determined above to each edge of the possible
sheet run.
3. JOG or otherwise move the head package until the center line of the sensing
windows is directly aligned with each of the maximum trim locations
determined above. Permanently mark the frames to identify the maximum trim
locations. These marks will make it easier to check or set up these locations
during maintenance operations.
4. Record the head position while the head package is at each of the marked
locations. Enter the recorded position into LHEOS and LFEOS, as specified
for your system.
LFEOS LHEOS
Center of
Sheet
Max Trim
Frame 2
Measure Limits
Frame 1
Measure Limits