Using the Filter Wheel

Normally we leave the filterwheel fixed with either the V or I filter in the light path, so that we can take CCD observations for variable star research. Other projects may require changing filters. This mini-manual will instruct you on how to correctly setup and use the filterwheel.

1) Telescope Setup:

Before booting up the CCD computer, when you are on the dome floor preparing to plug the CCD cable into the CCD, you can also do the following:

Get the power transformer/adapter ("wall wort") from the tall grey shelf in the back of the control room. Plug the 110V end into the power socket next to the reticle light control knobs, thread the wire around the telescope so it wont hang and get snagged, and plug the low-volt end into the small hole on the side of the filter wheel labeled "Power".
Connect the yellow cable to the port on the side of the filter wheel.
Connect the CCD cable to the port on the CCD as usual.

Boot up the computer as usual, enter MaxImDL, and select the "Setup" tab. The three boxes along the left of the window should read:

Apogee 1 = CCD
No Guider = Guider
DFM FW-82 = Filter.

If the windows show different values, choose the correct option from the drag-down menus. When all is OK, click Restart to initialize the camera. If a error dialog box appears telling you the filter wheel was not initialized, try the troubleshooting tip below. If no error occured, procede with setting the CCD Temp.

2) Changing Filters and Taking Images

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TROUBLESHOOTING

If you "Restart" to initialize the camera and filter wheel, and a dialog box appears warning "Cannot initialize filter wheel" (or something like that).

Problem: The computer probably has gotten confused about what COM Port it should use to send signals to the filter wheel. It seems to do this occasionally for no obvious reason.

Solution: Click the "Setup" tab. Ensure that the dragdown menu is set correctly: DFM FW-82 = Filter. Hit the "Filter" button and a dialog box will open. DON'T CHANGE any of the filter position assignments (eg, 1=U, 2=B, etc). Do ensure that the dragdown in "COM Port" is set to "COM1". Exit the window and hit "Restart" on the Setup window. If the error dialog box reappears, contact Dr. Layden for help.