On the left-hand side of the main window (click here for figure) are controls to open and close the shutter, to make simple single exposures, to move the crystal and detector goniometers and to change the source wavelength. On the right-hand side is a panel to make a single scan (multiple exposures) and a text output scrolled window.
There are text fields to enter new values and labels to indicate current values. Buttons are pressed to activate and abort commands. The button colors and labels change depending on the status of the command. A red color means a command is active and selecting the button will abort the command. A yellow color means the command failed or was aborted and selecting the button will re-initialize the corresponding hardware devices. Green is used to show that the shutter is closed. The default background color (usually blue or gray) is used to indicate inactive commands. Buttons and labels are sensitized and desensitized in response to user actions and hardware polling.
Shutter
The shutter button opens and closes the shutter “manually”. The button color is green if the shutter is thought to be closed and red if the shutter is thought to be open. If the shutter is closed, select the green button and pop-up a menu requesting confirmation that yes, you do want to open the shutter. Select the red button in the pop-up menu to open the shutter. If the shutter is open, just select the red button. For safety reasons, you need two button clicks to open the shutter, and a single button click to close the shutter. While the shutter is open, the button label is updated periodically to show the elapsed time in seconds since the shutter was opened. If the button is yellow, then dtcollect does not understand the state of the hardware shutter.
Expose
Single exposures are made with the Expose button. You can make 4 different kinds of exposures: Dark, Still and Rotation around Omega and Phi. All exposures are made at the current crystal and detector positions. For scans, the crystal goniometer “backs up” one-half of the requested width and rotates forward for the full width during the exposure. Thus, the exposure is centered at the current crystal position.
Select the type of exposure from the option menu, set the exposure time in seconds, and, if desired, set the rotation width in degrees (a width of 0.0 is like a still), then select the Expose button. The button color changes to red, the button label changes to Abort and the exposure is made. To abort the exposure, select the button while it is red. The current exposure time and width are updated periodically as the exposure is made. When the exposure is finished, the button returns to its original background color. If the shutter is opened (i.e. a still or scan), the shutter button also reacts and changes to red. If a goniometer motor moves (i.e. a scan), that button changes to red and the current goniometer position is updated in the panels below.
If the button changes to yellow, then dtcollect does not understand the state of the detector. Pressing the yellow button will re-initialize the detector hardware.
If the exposure was successful, dtcollect displays the image in the image display area in the right half of the main window. The image is also written to a file specified by the File Image template... command and the Scan Template textfield.
Scan
A single scan of multiple exposures are made with the Scan button. The exposure type, time and width settings of the Expose panel are used for each individual image in the scan. The number of adjacent images and the starting sequence number are specified in the Scan panel. The sequence number increment is set to 1. The goniometers are moved to the requested crystal, detector and source positions before the start of the scan. THIS IS DIFFERENT THAN FOR THE EXPOSE BUTTON. As the scan progresses, the last image file completed is updated in the Last file field.
Crystal position
Set the desired crystal goniometer position in the text fields in degrees, then select the Move button. The button color changes to red, the button label changes to Abort and the goniometer moves to the requested position. To abort the movement, select the button while it is red and labeled Abort. The current goniometer angles are update periodically as the axes move. When the goniometer stops moving, the button returns to its original color.
If the button changes to yellow, then an error occurred during the goniometer movement. Look in the scrolled text window for the reason. Possible errors are illegal angles or a real or predicted collision or jam. Check the goniometer and your input values, then press the yellow button to re-initialize the goniometer hardware.
Detector position
Set the desired detector goniometer position in the text fields. The distance is set in millimeters while the swing angle is set in degrees. Select the Move button to move the detector. The button color changes to red, the button label changes to Abort and the goniometer moves to the requested position. To abort the movement, select the button while it is red and labeled Abort. The current position are update periodically as the detector moves. When the detector goniometer stops moving, the button returns to its original color.
If the button changes to yellow, then an error occurred during the goniometer movement. Look in the scrolled text window for the reason. Possible errors are illegal angles or a real or predicted collision or jam. Check the goniometer and your input values, then press the yellow button to re-initialize the detector goniometer hardware.
Source wavelength
This control is sensitized at sites that can allow users to change the source wavelength such as synchrotrons. Set the desired source wavelength with the wavelength chooseror in the text field in Ångstroms or eV, then select the Move button. The button color changes to red, the button label changes to Abort and the wavelength moves to the requested position. To abort the movement, select the button while it is red and labeled Abort. The current wavelength position is update periodically. When the desired wavelength is reached, the button returns to its original color.
If the button changes to yellow, then an error occurred while changing the wavelength. Possible errors are an illegal wavelength or a real or predicted collision or jam. Check the hardware and your input values, then press the yellow button to re-initialize.
To the left of the requested wavelength text field, is a small button labelled ... that pop-ups the wavelength chooser. If you select a wavelength from this dialog, it replaces the value in the text field automatically.
Sensors
These are output only fields that display current values of any site-specific sensors on the diffractometer. Sensors might be used for ionization chambers, temperature controllers, etc. Consult your system manager to see what site-specific information is displayed here.
Command
This control does not function yet. For non-mouse users, simply use the Output
The lower-right of the main window is a scrolled text window for messages. This area
may be cleared by selecting the Clear output ... button in the Edit menu.
You can also interact with dtcollect through its menu bar.