Rockwell Automation 1398-PDM-xxx IQ Master Version 3.2.4 for IA-2000 and IQ-5000 Positioning Drive Modules, IQ-55 - Manual (Page 420)

398 Application Examples • Lane Diverter
Publication 1398-PM601A-EN-P — October 2000
APPENDIXES
Lane Diverter
Description
In material handling, it is often necessary to sort packages based on size. The machine sorts packages by
length, using a gate to steer the package to the appropriate output lane.
The ULTRA Plus or IQ Positioning Drive Module (PDM) is required to measure package length by
watching a photo-eye and an encoder connected to the conveyor. The axis must wait for any other pack-
age to exit the back of the gate before moving the gate to the new destination. Once a package has
cleared the back of the gate, it must be moved to the new position before the next package reaches the
back of the gate. To minimize mechanical wear and stress, the speed of the moves should be the slowest
speed possible that still allows the move to be done in time for the package to be sorted to the correct
lane.
The capability of the PDM to monitor an additional encoder and I/O points is used to measure package
length. The package is then sorted into three different size groups based on the measured length and a
new gate position is chosen. Once any package currently in the gate exits, the speed to move to the new
gate position is calculated (based on web speed, package position and distance to be moved) and the
move is executed. If the web changes speed during the move, the speed of the move will change to fol-
low it.
Design Considerations
A homing procedure appropriate to the mechanics of the machine is needed.
This program has been designed to track the progress of up to two packages at a time: one package can
be measured and tracked while a second package is directed to it’s destination position. If more than two
packages need to be tracked at a time, the program will need to be modified.
Consideration should be given to the gate length and the longest package length. The gate length needs
to be longer than the longest package length and should be long enough so that the difference between
the gate length and the longest package, divided by the fastest web speed, gives enough time to do the
worst case move. For this reason, the longest packages should be routed to the center lane, since this
results in the shortest average move distance for the moves that need to be completed in the shortest
time.
I/O Connections
Input 1: in_sense
This is the input sensor which is used to determine length and position of the incoming packages.
Input 12: exit_sense1, Input 13: exit_sense2, and Input 14: exit_sense3
Exit sensors are used to determine if a package is out of the gate.
System Parameters
The following system parameters will affect program behavior. System parameters that affect tuning, I/
O, etc. will also need to be set, but will not be covered here. See “Language Reference” on page 175 for
more details.
Scale
This is the number of motor encoder pulses/unit. The Scale parameter determines the units of numbers
entered for G3, G4 & G5 (target positions, described below). For example, this parameter may be set up
so that the target positions are in inches from the Home Position.
Scale2