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XPS-Q8 Controller
XPSDocumentation V1.4.x (EDH0301En1060 — 10/17)
7.3.2
Moves of Certain Displacements
These two move commands which don't use the same parameters, are explained below.
• MoveRelative
The action MoveRelative commands a relative move of a positioner similar to the
function GroupMoveRelative. However, the function GroupMoveRelative is not
available in the Referencing state. The relative move is specified by a positive or
negative displacement. The move is done with the SGamma profiler. The speed and
acceleration are the default values, or the last value defined by either a move on
sensor event, a MoveToPreviouslyLatchedPosition, or a
PositionerSGammaParametersSet.
• MoveToPreviouslyLatchedPosition
This action moves the positioner to the last latched position, see section 7.3.1:
"Move on sensor events" for details. It verifies there was a position latched since
this last GroupReferencingStart call. This is important because an old latched
position can still be in memory from a previous home search or referencing. And
moving to this previous latched position could have unexpected results. The move is
done with the SGamma profiler. The speed is specified by a parameter. The
acceleration is the default value, or the last value defined by a
PositionerSGammaParametersSet.
7.3.3
Position Counter Resets
"Position counter resets" sets the current position to a certain value. There are two
options: SetPosition and SetPositionToHomePreset. The main use of these actions is
when the positioner is at a well defined reference position after a
MoveToPreviouslyLatchedPosition action.
Another use of this action is for a "soft" system start by Referencing a group to a known
set position, without executing a home search process, for example. In this case, a
suggested sequence of functions follows:
GroupReferencingStart(GroupName)
GroupReferencingActionExecute(PositionerName, "SetPosition",
"None", KnownCurrentPosition)
GroupReferencingStop(GroupName)
SetPosition sets the current position to a value defined by a parameter.
SetPositionToHomePreset sets the current position to the HomePreset value stored in
the stages.ini configuration file. It is equivalent to a SetPosition of the same positioner
to the HomePreset value.
It is important that all positioners of a motion group are referenced to a position using
the SetPosition or SetPositionToHomePreset before leaving the Referencing state (see
example on page 94).
80
Motion Tutorial
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