Rockwell Automation 1784-PM16SE SoftLogix Motion Card Setup and Configuration Manual - Manual (Page 298)

Publication 1784-UM003A-EN-P – June 2003
290 Motion Object Attributes
Active
When active homing is chosen as the homing mode, the desired homing
sequence is then selected by specifying whether or not a home limit switch
and/or the encoder marker is used for this axis. Active homing sequences
always use the trapezoidal velocity profile. The Home Sequence attribute
section below describes the available active homing sequences.
Passive
Passive homing redefines the current absolute position of the axis on the
occurrence of a home switch or encoder marker event. Passive homing is most
commonly used to calibrate uncontrolled axes, although it can also be used
with controlled axes to create a custom homing sequence. Passive homing, for
a given home sequence, works similar to the corresponding active homing
sequence, as described below, except that no motion is commanded–the
controller just waits for the switch and marker events to occur.
Absolute
If the motion axis hardware supports an absolute feedback device, a Homing
Mode of “absolute” may be used. The only valid Home Sequence for an
absolute Homing Mode is “immediate”. In this case, the absolute homing
process establishes the true absolute position of the axis by applying the
configured Home Position to the reported position of the absolute feedback
device. Prior to execution of the absolute homing process via the MAH
instruction, the axis must be in the Axis Ready state with the servo loop
disabled.
Home Sequence and Home Direction
GSV/SSV Access Attribute Name Data Type Values
SSV/GSV Home Direction SINT 0 = uni-directional forward
1 = bi-directional forward
2 = unidirectional reverse
3 = bi-directional reverse
SSV/GSV Home Sequence SINT 0 = immediate (default)
1 = switch
2 = marker
3 = switch then marker