Rockwell Automation 1771-QB Linear Pos. - Manual (Page 29)

Positioning with the Linear Positioning
Module
Chapter 3
3Ć5
turn on a hardware start enable bit (using the command block), which causes
the module to delay movement to the commanded setpoint. The delay ends
and movement starts when you activate the hardware start input or send a
software start command in the command block.
command a setpoint while the axis is moving towards another setpoint. If the
new setpoint is in the opposite direction of travel, the axis decelerates to zero
speed (at the current deceleration rate) and then moves in the opposite
direction. If the new setpoint is in the same direction of travel, the old
setpoint is abandoned and the axis movement accelerates or decelerates to the
specified velocity and continues toward the new setpoint.
Jogging
In the manual mode, you position the actuator by jogging, i.e., directly
commanding movement in one direction or the other. You make these
movement commands by turning on forward or reverse jog bits (via the
command block) or activating forward or reverse hardware jog inputs (typically
via momentary action switches).
If you command a jog, the axis movement continues until the actuator reaches
the software travel limit or until you turn off the jog bit or jog input, whichever
occurs first.
Jog Rates
You define two jog rates (high and low) through the parameter block. You select
between low and high jog rates through the jog rate select bit in the command
block.
If you change jog rates (from high to low or from low to high) during a jog
movement, the axis decelerates/accelerates to the new rate.
Important: Jog commands are ignored in auto mode.
Motion Blocks
A motion block contains information similar to that which the setpoint block
uses to define axis movement. In addition, a motion block also contains trigger
conditions that will initiate a subsequent axis movement, thus changing the
motion of the axis without the intervention of the programmable controller. See
Chapter 9 for a full explanation of motion blocks.