ASCOM Library
IFilter
Sets or returns the current filter wheel position
Definition
Namespace: ASCOM.Common.DeviceInterfaces
Assembly: ASCOM.Common (in ASCOM.Common.dll) Version: 2.2.1+77356f79b05b579f6d860a4edd5934fda9fe29e4
Assembly: ASCOM.Common (in ASCOM.Common.dll) Version: 2.2.1+77356f79b05b579f6d860a4edd5934fda9fe29e4
C#
short Position { get; set; }VB
Property Position As Short
Get
SetProperty Value
Int16Remarks
Must be implemented, must not throw a NotImplementedException.
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.
Exceptions
| InvalidValueException | Must throw an InvalidValueException if an invalid position is set |
| NotConnectedException | When Connected is False. |
| DriverException | An error occurred that is not described by one of the more specific ASCOM exceptions. Include sufficient detail in the message text to enable the issue to be accurately diagnosed by someone other than yourself. |