Rockwell Automation 1771-QC , D17716.5.25 SER/B SERVO POS - Manual (Page 146)

Formatting and Interpreting Data Blocks
Chapter 7
7Ć64
accelerate or decelerate to the final rate for the first move in the current
moveset, and continue moveset execution.
If the axis is moving, and the endpoint of the first move of the moveset is
in the direction opposite that of axis motion, the servo positioning
assembly:
1. executes a slide stop
2. moves the axis to the endpoint of the first move in the current
moveset using the values programmed for that move
3. continues moveset execution
If the servo positioning assembly is executing an escape move when you
issue the begin command, it ignores the begin command. If you issue the
begin command after the escape move is complete, the servo positioning
assembly executes the first move of the normally executed moveset that
follows the escape moveset. (That is, the moveset specified by the next
moveset pointer of the escape moveset.)
Bit 2 Preset
In the manual mode, turn on bit 2 to generate a preset command. The axis
must be stopped for this command to be executed. If a
get-new-preset-value command (second control word) has been
previously executed, the servo positioning assembly sets its current
position value to the current preset position values for the axis in the
command block. If no get-new-preset-value command has been executed
since power-up or reset, the servo positioning assembly sets its current
axis position value to zero.
In addition, execution of a preset command clears the axis offset
accumulator, setting its value to zero.
The servo positioning assembly does not request write block transfer of
the preset words of the command block unless you issue a
get-new-preset-value command. Otherwise, only the first and second
control words for each axis are transferred in the command block.
Furthermore, when you include the preset words in the command block in
response to a get-new-preset-value command, only the axis requesting the
new preset value recognizes its new values.