ADLINK Technology PCI-8254, Руководство пользователя

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162 Motion Control Theory
4.10 Application Functions
4.10.1 Electronic Gearing
Electronic gear function: You may set up movement relation of one
axis (slave axis) against another axis (master axis) that is similar
to a mechanical gear structure. Relation between two gears is
usually expressed with gear ratio. Take example. For a pair of
gears with gear ratio 1:2, then the Y (slave) axis rotate 2 turns
when the X (master axis) rotate 1 turn. Similarly, you can set up
electronic gear ratio so that when the master axis executes control
motions, the slave axis rotate in accordance with given gear ratio.
This controller provides 2 modes: standard and gantry modes.
These two modes differ in that the gantry mode is designed for
dual drives gantry mechanism exclusively where two motors are
used to drive one rigid connected mechanism. It features special
safety and control behaviors. These two modes are described in
sections below.
4.10.1.1 Standard Mode
To set up a electronic gear in standard mode: select a slave axis,
all parameters and commands are set by reference to this axis.
Set up axis parameters listed below before initiating electronic
gear mode:
Use APS_start_gear (slave axis ID) to enable electronic gear
function after setup. After the electronic gear function is enabled,
the slave axis moves along with the master axis by gear ratio
setup values. As the master axis may not be motionless, you may
set up appropriate engage rate for the slave axis to move at given
velocity from zero to given gear ratio and to prevent vibration
caused by very fast instant acceleration. In addition, gear ratio in
this mode can be changed dynamically where the changing
process is subject to engage rate.
Engage rate = Gear ratio / Engage time
Param. No. Define symbol Description
60h (96) PRA_GEAR_MASTER Gear master
61h (97) PRA_GEAR_ENGAGE_RATE Engage rate
62h (98) PRA_GEAR_RATIO Gear ratio