User's Guide to ShARCS

Table of Contents

Summary Table
Detector Characteristics
Filters, Grisms, Apertures, Polarimeter
Software Overview
Data Taker GUI
Filter & Aperture Wheel GUI
Image Display GUI
Sound server
Temperature Monitor
Observing Procedures and Tips
FITS Header Keywords

Data Archive
Mt. Hamilton Homepage

Filter and Aperture Wheel GUI

The ShARCS filter and aperture wheels are controlled from the saowheels GUI (Figure 1). The GUI is started from any of the user computers with the command saowheels_gui.

Figure 1: Filter and aperture wheel GUI, saowheels_gui.

There are three wheels inside the cryogenic environment of ShARCS, two filter wheels, Filter #1 and Filter #2, and an aperture wheel. There is a third, warm, filter wheel, SciFilt, outside of ShARCS. All four wheels are operated in the same manner. Click on the position name (for example, Filter #1 click on Ks in Figure 1) and a menu of available filters will be displayed. Select the desired filter. If different from the current position, the background will be yellow and a green arrow will appear in the GUI (see Figure 2). To move to the desired position, click on the green arrow.

Figure 2: Move pending, showing item with yellow background and green arrow button to initiate move.

Status of the motor is displayed via the icon to the right of each motor (see Table below for the icons). A green checkmark means that the motor is in position and may be moved if desired. A yellow triangle indicates a warning and a red X indicates an error. To get more information about a warning or error, click on the icon and a detail panel for the motor (Figure 3) will appear. Warnings are usually relatively benign and one can try moving the motor again to see if the warning clears. Errors may require contacting a telescope technician or support astronomer for assistance.

Motor Status Icons
Ready/OK Moving
Warning Error
Locked Calibrating

Figure 3: Detail panel for Filter Wheel 1.

The detail panel displays a great deal of information, but most important for the observer are the fields towards the bottom for error: and message: to help evaluate problems with the assistance of a telescope technician or support astronomer. The Stop motion button will stop the motion of the motor, especially if there is sa problem. The Re-calibrate button willinitialize the homing sequence for the motor, useful if one is unsure the wheel is positioning correctly.

The contents of the filter wheels may change, so one should refer to the Summary Table for the current contents. Note that the following items are always available:
Permanently Installed Filters
Filter 1Filter 2

The menu bar has two items, File and Actions. The File menu has three options (Figure 4) which are self-explanatory with the keyboard shortcuts in parentheses: Increase font size (Ctrl++), Decrease font size (Ctrl+-), and Quit (Ctrl+q).

Figure 4: File Menu

The Actions menu (Figure 5) had a number of options concerning the motion of the motors.

Figure 5: Actions Menu

Cancel Pending (Ctrl+c) allows one to clear the GUI of any pending moves, as indicated by a yellow background and restore the display to the current motor positions.

Apply Pending (Ctrl+m) allows one to move all motors to the desired positions at once, rather than clicking the individual green arrow buttons for each wheel.

Enable Motion will set the state of each motor to its normal default when ready to be moved. If one sees a yellow triangle, enabling motion will often rest it to the OK (green checkmark icon) state. If the state does not change to OK, there may be some other problem that requires assistance from a support astronomer.

Calibrate submenu has two items, Calibrate All and Calibrate Uncalibrated Stages. Calibrate All will calibrate all three wheels regardless of their current state. Calibrate Uncalibrated Stages will only calibrate those wheels which are not currently calibrated.

Addition Technical Information

The saowheels_gui software communicates with server software known collectively as the saomot dispatchers. In actuality there are five saomots: saomot1, saomot2, etc. saowheels_gui needs only to communicate with saomot3, as the other dispatchers are for motors in the ShaneAO system. saomot3 runs on the computer shanenvc and can be started from that computer with the command ao start saomot3. To restart the dispatcher type ao restart saomot3. To stop it, type ao stop saomot3. To get status information type ao status saomot3.

The motor encoder positions for each wheel are as follows:
Filter 1010003000500070009000110001300015000
Filter 2010003000500070009000110001300015000
Last modified: Thu Jun 17 18:51:46 PDT 2021