Rockwell Automation GMLC Reference Manual - Manual (Page 727)

Publication GMLC-5.2 - November 1999
690 Using the RIO Adapter Option
While homing is in progress, (provided there are no faults active on the
axis) both the axis locked and axis fault dedicated discrete RIO outputs
from the motion controller for the selected axes are cleared. When
homing has finished successfully and the position error of the axis is less
than the position lock tolerance, the axis locked dedicated discrete RIO
outputs from the motion controller for the selected axes are set. If a fault
occurs during homing, the axis fault outputs for the selected axes are set,
but the axis locked outputs are cleared. See Dedicated Discrete Outputs
later in this section for more information on the axis locked and axis fault
bits.
The simple PLC ladder logic shown here for homing axes should not be
used in the same PLC program with the ladder logic shown later for
jogging axes, or improper operation can result. To provide homing and
jogging together via the PLC, the home and jog functions must be
interlocked with each other. This ensures that homing one axis does not
inadvertently jog (or stop jogging) another axis, or vice-versa, because
both functions use the same axis select bits.
Jogging Axes
To directly jog an axis from the PLC:
1. Select the axis by setting the appropriate axis select bit (0 – 3).
2. Specify the jogging direction by selecting the jog selected axes bit for
the direction:
• SLC output 9 or PLC output 11 for the positive direction;
• SLC output 10 or PLC output 12 for the negative direction
Note: Do not set a Jog Selected Axes bit while the application
program in the motion controller is running.
To jog more than one axis simultaneously, set more than one axis select
bit. Axes can be jogged only by using these bits while no application
program is running in the motion controller. These bits have no effect if
set while the application program is running.