chara:trouble_shooting
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chara:trouble_shooting [2020/01/28 03:02] charaobs |
chara:trouble_shooting [2020/07/10 15:07] jones |
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| - | This document describes how to solve common problems that sometimes arise at the array. | + | This document describes how to solve common problems that sometimes arise at the array.test |
| ===== Can't find fringes ===== | ===== Can't find fringes ===== | ||
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| * Were the clocks synced? Make sure the [SYNC CLOCKS] button on Cosmic Debris has been pushed to start the night. If the OPLE server does not display the correct CHARA time and the errors don't read (0) or (1), the clocks were not synced. As the VME runs on its own clock and does not use the NTP server, it can drift over the course of the night and cause problems with finding fringes, even if it was synced at the start of the night. Syncing the clocks multiple time during the night may help to avoid this hidden clock problem. | * Were the clocks synced? Make sure the [SYNC CLOCKS] button on Cosmic Debris has been pushed to start the night. If the OPLE server does not display the correct CHARA time and the errors don't read (0) or (1), the clocks were not synced. As the VME runs on its own clock and does not use the NTP server, it can drift over the course of the night and cause problems with finding fringes, even if it was synced at the start of the night. Syncing the clocks multiple time during the night may help to avoid this hidden clock problem. | ||
| - | * Did the Astrolib update on OPLE? If the job queue is stopped too soon after slewing on Cosmic Debris, the correct calculations for the carts will not be done by OPLE and you may be searching for fringes with the wrong star data. Hit STAR ACQUIRED on CD to update ople. The proper star can also be entered by typing hd #### into the OPLE server and hitting ENTER. | + | * Did the Astrolib update on OPLE? If the job queue is stopped too soon after slewing on Cosmic Debris, the correct calculations for the carts will not be done by OPLE and you may be searching for fringes with the wrong star data. Hit STAR ACQUIRED on CD to update ople. The proper star can also be entered by typing hd #### into the OPLE server and hitting ENTER. |
| - | * Are the PoP's correct? | + | * Are the PoP's correct? After a PoP change, the PoP's are sometimes not updated in CD or ople. |
| - | * Are the carts behaving or are there vibrations or jumps of 100 or more microns every 3-6 seconds? | + | * Are the carts behaving or are there vibrations or jumps of 100 or more microns every 3-6 seconds? Restart the ople server if they persist. |
| * Is the target a high proper motion star? Red dwarfs are close stars and can have high proper motions. Scan a wider range to see if it is outside of the usual calculated scan range. Binaries can also have very high offsets from the expected position due to mistakenly using astromod calculations from the companion star. | * Is the target a high proper motion star? Red dwarfs are close stars and can have high proper motions. Scan a wider range to see if it is outside of the usual calculated scan range. Binaries can also have very high offsets from the expected position due to mistakenly using astromod calculations from the companion star. | ||
| * Do you have enough flux from each telescope or on each baseline? | * Do you have enough flux from each telescope or on each baseline? | ||
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| * ENABLE the telescope using the telescope or dome GUI. Check to see if the command and telescope positions are correct. If they are, then turn on the power for the telescope drives. Re-enter the star information by entering the HD number in the telescope server and click [GO NEXT] to send the telescope to the star. Make sure that the telescope is behaving as expected. The telescope might have drifted a bit, so if you can't find the star, it might be necessary to use the Telrad on a bright star to re-initialize the pointing. | * ENABLE the telescope using the telescope or dome GUI. Check to see if the command and telescope positions are correct. If they are, then turn on the power for the telescope drives. Re-enter the star information by entering the HD number in the telescope server and click [GO NEXT] to send the telescope to the star. Make sure that the telescope is behaving as expected. The telescope might have drifted a bit, so if you can't find the star, it might be necessary to use the Telrad on a bright star to re-initialize the pointing. | ||
| * Restart commands for the dome servers are also listed on the desktop in a text file. | * Restart commands for the dome servers are also listed on the desktop in a text file. | ||
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| ==== Telescope is tracking poorly, overshooting in slew, oscillating. ==== | ==== Telescope is tracking poorly, overshooting in slew, oscillating. ==== | ||
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| This might mean that the gain for the tracking servo is wrong. Note that changing this gain can be dangerous, especially if you set it too high as that can cause the telescope to oscillated and damage the drives. Please only do this if you are very very sure that it is necessary. Symptoms of bad gain are: The scope over shoots the position while slewing. The star will be seen to move out of the window and may come back after a few seconds. This means the slewing gain is too low. The scope oscillates when tracking or after a slew. The star will be tracing an ellipse, figure eight or other looping shape. This means the tracking gain is too low. You can damp this out with the telescope or dome gui by disabling the scope, then re-enabling it. Adjust the gain upward and watch it on the next slew. In all cases if either gain is too high the scope will go into "Fog Horn" mode, which is bad. You always want to use the lowest gain that still allows the scope to work as best as possible. If the tiptilt tells you the scope is oscillating slowly, the gain may be too low. If it is oscillating quickly it may be too high. On 10-22-2016, the gain settings were: | Scope | AZ Slewing | This might mean that the gain for the tracking servo is wrong. Note that changing this gain can be dangerous, especially if you set it too high as that can cause the telescope to oscillated and damage the drives. Please only do this if you are very very sure that it is necessary. Symptoms of bad gain are: The scope over shoots the position while slewing. The star will be seen to move out of the window and may come back after a few seconds. This means the slewing gain is too low. The scope oscillates when tracking or after a slew. The star will be tracing an ellipse, figure eight or other looping shape. This means the tracking gain is too low. You can damp this out with the telescope or dome gui by disabling the scope, then re-enabling it. Adjust the gain upward and watch it on the next slew. In all cases if either gain is too high the scope will go into "Fog Horn" mode, which is bad. You always want to use the lowest gain that still allows the scope to work as best as possible. If the tiptilt tells you the scope is oscillating slowly, the gain may be too low. If it is oscillating quickly it may be too high. On 10-22-2016, the gain settings were: | Scope | AZ Slewing | ||
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| To add an anchor to the wikipage, type the following where you want the anchor inserted (without the spaces between the symbols): \\ [ [ #AnchorName ] ] \\ \\ Highlight the text you want to be a link to the anchor, click the link symbol above and select anchor. Select a page(such as Trouble Shooting) where the anchor is located and give the same name for the anchor. \\ \\ Last updated 2017-04-12 | To add an anchor to the wikipage, type the following where you want the anchor inserted (without the spaces between the symbols): \\ [ [ #AnchorName ] ] \\ \\ Highlight the text you want to be a link to the anchor, click the link symbol above and select anchor. Select a page(such as Trouble Shooting) where the anchor is located and give the same name for the anchor. \\ \\ Last updated 2017-04-12 | ||
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chara/trouble_shooting.txt · Last modified: 2024/06/18 00:21 by charaobs
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