Camera and Filter Wheel Box Control

Overall layout

The camera and filter wheel box control window looks like this:

The camera and filter wheel control window is divided into three raised panels::

Filter Wheel Box

This panel contains buttons which send simple commands to the filter wheel box.

CCD

This panel contains controls for redoing out the CCD, and some entry boxes for specifying the header information for images taken in this way.

Exposure sequence

This panel allows for taking arbitrary sequences of exposures without performing many of the tasks normally associated with taking an exposure of an object (such as slewing to it).

Filter Wheel Box

Filter wheel control buttons

The buttons on the first row of this panel send the filter wheel to the position containing the designated filter:

u

Sends the filter wheel to position 1, where the "u" filter is usually installed.

This button is the GUI equivalent of

mt> selectFilter u

g

Sends the filter wheel to position 2, where the "g" filter is usually installed.

This button is the GUI equivalent of

mt> selectFilter g

r

Sends the filter wheel to position 3, where the "r" filter is usually installed.

This button is the GUI equivalent of

mt> selectFilter r

i

Sends the filter wheel to position 4, where the "i" filter is usually installed.

This button is the GUI equivalent of

mt> selectFilter i

z

Sends the filter wheel to position 5, where the "z" filter is usually installed.

This button is the GUI equivalent of

mt> selectFilter z

blank

Sends the filter wheel to position 6, where there is usually a weight installed.

This button is the GUI equivalent of

mt> selectFilter b

Shutter control

The buttons on the second row open and close the shutter.

Close

Closes the shutter.

This button is the GUI equivalent of

mt> fwbCloseShutter

Open

Opens the shutter

This button is the GUI equivalent of

mt> fwbOpenShutter

Timed exposure

The third and final row of controls in the filter wheel box frames allows the user to open the shutter for a specified length of time.

time

The time entry box holds the time (in seconds) to keep the shutter open. This should be a positive integer.

Take timed exposure

Hitting this button opens the shutter for the time specified in the time entry box.

This button is the GUI equivalent of

mt> fwbSetExposureTime $exposureTime

mt> fwbStartExposure

Note that this button does not read out the CCD. It merely opens and closes the shutter.

CCD

Subarray height

The first row of the CCD frame contains radio buttons allowing the observer to select the height of the subarray to be read. This is dangerous to use, because it can badly confuse the DA. Leave the subarray height at 2048 at all times.

CCD readout controls

The second row of controls here allows the CCD to be read out, and lets the user specify some of the header values in the resulting image.

Target name

This entry box should contain desired value for the "TARGET" keyword in the header of the image produced when the "Read out the CCD" button is hit. Note that it has no effect on the headers of images taken with commands or buttons outside the "Camera and FWB control" window.

Filter

This entry box should contain the desired value for the "FILTER" keyword in the header of the image produced when the "Read out the CCD" button is hit. It does not affect the filter wheel in any way, and has no effect on the headers of images taken with commands or buttons other than the "Read out the CCD" button in this frame.

Read out the CCD!

Hitting his button causes the CCD to be read out. No other operations (opening or closing the shutter, etc.) are performed. The target name and filter listed in the header of the resultant image will be that specified in the "Target name" and "filter" entry boxes, above.

This button is the GUI equivalent of

mt> setSectionSize $subarrayHeight

mt> set targetData(name) $targetName

mt> set targetData(flavor) Man

mt> set targetData(epoch) 2000

mt> set targetData(filterList) $filter

mt> set targetData(exposureList) 0

mt> takeSequence -informGUI

where $subarrayHeight corresponds to the height selected in the "subarray height" checkboxes (and should be kept at 2048), $targetName corresponds to the "Target name" entry box, and $filter corresponds to the filter entry box. Note that, in practice, one is unlikely to use the setSectionSize command (because it will be set to 2048 by default, which is where you will want it), and is likely to set the targetData values interactively using setTarget.

Exposure sequence

This frame allows arbitrary sequences of exposures to be taken. It contains 3 controls:

Filters

This entry box should contain an ordered, space separated list of filters in which exposures are to be taken.

For example, if you wish to take 5 exposures, the first of which is through the g filter, the second and third of which are through the r filter, and fourth of which is through the z filter, and the last of which is again through the r filter, the box should contain:

g r r z r

Exposures

This entry box should contain an ordered, space separated list of the exposure times for each exposure.

Continuing the above example, if we want out first (g) exposure to have an exposure time of 10 seconds, the second and third (both r) exposures to have exposure times of 5 and 30 seconds, respectively, the fourth (z) exposure to have an exposure time of 15 seconds, and the final (r) exposure to have an exposure time of 120 seconds, then this box should contain:

10 5 30 15 120

Take sequence of exposures

This button will take a sequence of exposure according the to values in the "Filters" and "Exposures" entry boxes, described above. The value of the "Target name" entry box, found in the second ("CCD") panel of the camera and FWB control window, will be entered into the header as the target name.

The example described above is the GUI equivalent of the following commands:

mt> setSectionSize $subarrayHeight

mt> set targetData(name) $targetName

mt> set targetData(flavor) Man

mt> set targetData(epoch) 2000

mt> set targetData(filterList) {g r r z r}

mt> set targetData(exposureList) {10 5 30 15 120}

mt> takeSequence -informGUI

where $subarrayHeight corresponds to the height selected in the "subarray height" checkboxes (and should be kept at 2048) and $targetName corresponds to the "Target name" entry box. In practice, one is unlikely to use the setSectionSize command (because it will be set to 2048 by default, which is where you will want it), and is likely to set the targetData values interactively using setTarget.

Last modified 6/21/2001 by E. H. Neilsen, Jr.