Parker HPD2N, Руководство пользователя, Страница: 70 / 125

Parker Hannifin S.p.A. - S.B.C. Division HPD N User’s Manual
67
Example 8: execution of modulus in digital locking
(FILE: E001.HPD)
To obtain the following functionality: with reference to the figure assume you have a
conveyor transporting product and a blade roller driven by the HPD drive. At start up on an
external command the blade roller is aligned with a zero reference (proximity sensor). On
receipt of the next pulse command, which is generated by a product detection sensor, the
blade roller drive locks onto the conveyor master so that the product is always cut at precisely
the same length; when the cut is terminated the blade roller reassumes the starting position
awaiting the next cutting command.
In this case the program permits the homing procedure (see chapter 1) and then, on receipt
of the command from the product sensor, it assumes digital locked mode and covers a space
equal to the value of Pr87:86; when it reaches this distance the drive unlocks and ramps down
to the standby position defined by parameter Pr89:88 = modulus. Note that one motor shaft
revolution corresponds to 4096 steps so the modulus value to set is equal to the number of
steps required by the motor shaft to execute a full revolution of the blade roller. The value of
Pr87:86 must be less than the value of the modulus (=Pr89:88).
The master encoder mounted to the conveyor shaft provides the drive with a position
reference during the digital locking phase.