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FilterWheelPosition Property

Sets or returns the current filter wheel position

Namespace:  ASCOM.DriverAccess
Assembly:  ASCOM.DriverAccess (in ASCOM.DriverAccess.dll) Version: 3351c4f3fa64146a7efd5b51ed4591e32a0a5484
Syntax
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public short Position { get; set; }

Property Value

Type: Int16

Implements

IFilterWheelV2Position
Exceptions
ExceptionCondition
InvalidValueExceptionMust throw an InvalidValueException if an invalid position is set
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
Write a position number between 0 and N-1, where N is the number of filter slots (see Names). Starts filter wheel rotation immediately when written. Reading the property gives current slot number (if wheel stationary) or -1 if wheel is moving.

Returning a position of -1 is mandatory while the filter wheel is in motion; valid slot numbers must not be reported back while the filter wheel is rotating past filter positions.

Note

Some filter wheels are built into the camera (one driver, two interfaces). Some cameras may not actually rotate the wheel until the exposure is triggered. In this case, the written value is available immediately as the read value, and -1 is never produced.

See Also