ADLINK PCI-8258 - Manual (Page 122)

108 Motion Control Theory
4.4 Home Move
After power on and before executing any motion control, a motion
control system executes home movement to set up the zero
position of the coordinate system.
Commonly available stepper motor, servo drive or linear motor
mechanism accompanied by optical scale employs incremental
type encoder which requires some mechanical signal to set up the
original position during home operation. These mechanical signals
are ORG, EZ, PEL, and MEL. Some servo drives are featured with
absolute type encoder, e.g. J3-B type (SSCNET 3) of Mitsubishi,
that require at least one home movement after system
initialization. No more home operation is required after the
absolute coordinate system is established.
After the homing command is received, the controller starts
searching for original position / zero position with the help of some
external signals. After the home movement is completed the
controller axis stops at the original postion while command
position and feedback position reset to zero. All the home
movement related operations are executed by the controller
automatically. No user interaction is required. Just wait it to
complete automatically.
You can finish home movement operation by steps described
below:
• Set up home mode and relevant parameters
• Start up home move
• Wait for home move to complete. (You may check the status by
polling or interrupt.)
• If home move does not complete successfully you may
troubleshooting by steps described below
Relevant APS API described below:
I32 APS_motion_status (I32 Axis_ID);
Relevant axis parameters:
Param. No. Define symbol Description
10h (16) PRA_HOME_MODE Home mode settings
11h (17) PRA_HOME_DIR Homing direction settings
12h (18) PRA_HOME_CURVE Home move S-factor
13h (19) PRA_HOME_ACC Homing acceleration/deceleration settings
15h (21) PRA_HOME_VM Homing maximum velocity