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FocuserMove Method

Moves the focuser by the specified amount or to the specified position depending on the value of the Absolute property.

Namespace:  ASCOM.DriverAccess
Assembly:  ASCOM.DriverAccess (in ASCOM.DriverAccess.dll) Version: 3351c4f3fa64146a7efd5b51ed4591e32a0a5484
Syntax
public void Move(
	int Position
)

Parameters

Position
Type: SystemInt32
Step distance or absolute position, depending on the value of the Absolute property.

Implements

IFocuserV3Move(Int32)
Exceptions
ExceptionCondition
NotConnectedExceptionIf the device is not connected.
DriverExceptionAn error occurred that is not described by one of the more specific ASCOM exceptions. The device did not successfully complete the request.
Remarks
If the Absolute property is True, then this is an absolute positioning focuser. The Move command tells the focuser to move to an exact step position, and the Position parameter of the Move method is an integer between 0 and MaxStep.

If the Absolute property is False, then this is a relative positioning focuser. The Move command tells the focuser to move in a relative direction, and the Position parameter of the Move method (in this case, step distance) is an integer between minus MaxIncrement and plus MaxIncrement.

BEHAVIOURAL CHANGE - Platform 6.4

Prior to Platform 6.4, the interface specification mandated that drivers must throw an InvalidOperationException if a move was attempted when TempComp was True, even if the focuser was able to execute the move safely without disrupting temperature compensation.

Following discussion on ASCOM-Talk in January 2018, the Focuser interface specification has been revised to IFocuserV3, removing the requirement to throw the InvalidOperationException exception. IFocuserV3 compliant drivers are expected to execute Move requests when temperature compensation is active and to hide any specific actions required by the hardware from the client. For example this could be achieved by disabling temperature compensation, moving the focuser and re-enabling temperature compensation or simply by moving the focuser with compensation enabled if the hardware supports this.

Conform will continue to pass IFocuserV2 drivers that throw InvalidOperationException exceptions. However, Conform will now fail IFocuserV3 drivers that throw InvalidOperationException exceptions, in line with this revised specification.

See Also