User Manual
Chapter 5
GFK-1742F
Jan 2020
DSM314 to Host Controller Interface
149
will immediately take effect. Rate Override can be used to adjust the programmed
velocity (not acceleration) of a particular move or a set of moves on any given axis.
4.03 Position Increment Without Position Update. (User units) This command offsets the
axis position from -128 to +127 user units without updating the Actual Position,
Unadjusted Actual Position (UAP), or Commanded Position. The DSM314 will
immediately move the axis by the increment commanded if the servo is enabled.
Position Increments can be used to make minor machine position corrections to
compensate for changing actual conditions. See Chapter 6, “Non
-Programmed
Motion,” for more information on using Position Increment Commands with the
DSM314.
Note:
The %AQ Position Increment without Position Update command (21h) does not change
the UAP. If an application uses this command, the UAP will no longer match Actual
Position. For details on the operation of UAP, see page 156.
4.04 Move At Velocity. (User units/sec) This command is executed from the CPU to move
the axis at a constant velocity. The active Jog Acceleration rate and configured Jog
Acceleration Mode are used for Move at Velocity commands. Axis actual position
data will roll over at the configured Hi or Lo Limit when reached during these moves.
See Chapter 6, “Non
-Programmed Motion, for more information on the Move at
Velocity Command.”
4.05 Set Position. (User units) This command changes the axis position register values
without moving the axis. Operation of the command depends on the axis
configuration:
Servo Axis - The Commanded Position and Actual Position values will both be
changed so that no motion command will be generated. The Actual Position will be
set to the value designated and the Commanded Position will be set to the value +
Position Error. Set Position cannot be performed when the Moving %I bit or the
Program Active %I bit is ON. Set Position is allowed if the In Zone %I bit is OFF as long
as Actual Velocity is ≤ 100 cts/sec. The position value must be
within the End of
Travel Limits and Count Limits or a status error will be reported. The Position Valid
%I bit is set after a successful Set Position command. See Appendix C for
considerations when using absolute mode encoders. The Set Position command is
commonly used to set the starting position reference point to zero (or another
value) without homing the axis.
Aux Axis - Commanded Position is set to the command data. For an Aux Axis, Actual
Position is independent of Commanded Position and is not affected by Set Position.
Refer to paragraph 4.18 Set Aux Encoder Position to set Actual Position for an Aux
axis encoder. Set Position cannot be performed when the Moving %I bit or the
Program Active %I bit is ON. The position value must be within the End of Travel
Limits or a status error will be reported.
Note:
When a digital servo system with absolute encoder (Feedback Mode = Absolute) is first
powered up after removal or replacement of the encoder battery, the encoder must be
rotated past its internal reference point. If this is not done the Set Position command will
be ignored and Error Code 53h (Set Position before encoder passes reference point) will
be reported.