David's Astronomy Pages
 Notes - Session 1375 (2025-11-20)

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Bullet Session Aims & Highlights
 - Observing Result
 - Night Summary Plot
 - Session Event Log
Bullet Operational Issues
- Critical Issues (0),  Major Issues (2),  Minor Issues (3),  Small Defects (4),  Continuous Improvement (1)
- Figures (1)
   
Bullet Images from 2025-11-20  >>           
   
Bullet Investigation - Failed Dome Closure (shutter only 80% closed)
Bullet USBTreeView - V4.6.4
   

Session Aims & Highlights (2025-11-20)

Main aims

  1. Targets.  Acquire images of a selection of variable stars, nearby stars, comets & deep sky targets as allowed by sky conditions.
  2. C/2025 K1 (ATLAS) - Acquire images of comet C/2025 K1 (ATLAS), attempt to image the recently annouched split in comet, and new objects C/2025 K1-B & C/2025 K1-C
  3. 3I/ATLAS - Acquire images of the interstellar comet 3I/ATLAS (alias C/2025 N1 (ATLAS)
  4. Observatory System & Software.  Achieve a full test of the observatory system following complete reinstallation of Windows 11 and Observatory Software on the AllSky/Weather Computer, and the update of multiple Astro Suite programs (AstroMain, AstroPlan, AstroWeather, AstroAllSky, AstroObsCam, AstroNorthCam and AstroLaunch)

 Equipment & Software

Highlights

NotesNotes

Summary Plots & Logs

Observing Plan
Image
  
Observing Result
Image
   
Image
 
Dome & Scope Slewing Performance
Image
  
Slew/Centering Performance
Image
  
Guiding Performance
Image
  
Sky Conditions (Locate Frames)
Image 
  
Night Sky Summary Plot
Top axis: Sky Brightness at Zenith (in ADU/s)
Lefthand axis: Local Time (hh LT). Righthand axis: Sun Altitude (degs)
Note:  The NorthCam Star Count line is unreliable and should be ignored
(The AstroNorthCam 'Find' Star method is producing many false positives from clouds)
Image   
  
Actual Weather vs Pre-Session Weather Forecast
Image
Image
 
Session Event Log
Time     Event Detail
17:39:13 Session Monitoring AutoStart monitoring for Live Session opportunity between 17:39 & 06:07
17:39:16 Session AutoStarting Session autostarting (17:39)
17:39:29   CCDSoft Restarting CCDSoft being restarted (to set AutoSave No.)
17:39:44 Session Created Session Created (Live, 2025-11-20 S01375, ImageSaveNum: 1375001)
17:39:52   Scope Switched On Telescope Power has been switched on via UPB Switch
17:41:39   Services Started Observatory Services started
17:41:50 Observatory (Auto) Observatory placed in Fully-Automated Mode
17:41:52 Session Pending Session pending (2025-11-20)
17:41:54 Session Initiating Session initiating (2025-11-20)
17:42:13   Camera1 Connected SBIG Camera connected (Set point -25°C)
17:42:15   Plan Requested Observing Plan requested from AstroPlan (1.44)
17:43:05   Plan Loaded Observing Plan loaded to queue (Plan ID: 1162)
17:43:48   Telescope Connected Telescope connected (TheSky6)
17:44:13 Session Equilibration Session ready to Open Dome
17:44:58   Dome Opened Dome opened (Opening time 45s, Zigbee 41s)
17:45:18 Session Running Session running
17:45:21   Queue Started Observing Queue started (40 targets selected)
17:45:24     Target Started (NrZen) Target started (Focus Field 22, HIP 108888)
17:45:40       Dome Unparked Dome unparked
17:51:09       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
17:53:56       Focusing Completed Foc1 AutoFocus Completed (Profile No 1, wide)
17:56:17       Focusing Completed Foc1 AutoFocus Completed (Profile No 1)
17:56:40       Focusing Started-Foc2 Foc2 Focusing Started (Secondary Scope, using ShCap)
17:58:20       Focusing Completed Foc2 AutoFocus Completed (Profile No 2, wide)
18:00:05       Focusing Completed Foc2 AutoFocus Completed (Profile No 2)
18:00:26     Target Completed (NrZen) Target completed (Focus Field 22, HIP 108888)
18:00:31     Target Started (1/40) Target started (1/40, UGC 10058 w/SN2025gvs)
18:04:41       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
18:08:10       Focusing Completed Foc1 AutoFocus Completed (Profile No 3)
18:19:12       SoftSuspend Called Soft Suspend called due to Deteriorating Conditions (too few stars)
18:22:02       SoftSuspend Cancelled Soft Suspend is cancelled due to improved conditions
18:24:11     Target Completed Target completed (1/40, UGC 10058 w/SN2025gvs)
18:24:15     Target Started (2/40) Target started (2/40, 2MFGC 13744 w/SN2024afyu)
18:28:33       Focusing Skipped Foc1 focusing skipped - star is too dim (TCF-LSI)
18:38:54       SoftSuspend Called Soft Suspend called due to Deteriorating Conditions (too few stars)
18:44:40     Target Completed Target completed (2/40, 2MFGC 13744 w/SN2024afyu)
18:44:42   Queue Paused Queue paused for Session Suspension
18:44:44 Session Suspending Session suspending
18:45:45   Dome Closing Dome closure hasn't finished after 60s (ShutterState=Closing)
18:47:05 Session Suspended Session suspended
18:47:35   Pulsar Dome Recovering Dome
18:47:50   Pulsar Dome Restarting Dome Controller
18:48:25   Pulsar Dome Dome Controller has been restarted
18:48:38   Pulsar Dome Dome Service has been restarted
18:49:15   Telescope Connected Telescope connected (TheSky6)
19:02:39     Target Cancelled Target cancelled (3/40, SN 2025taz) due to cloud
19:14:57     Target Cancelled Target cancelled (4/40, GCVS CY Lyr) due to cloud
19:25:15     Target Cancelled Target cancelled (5/40, GCVS BL Lac) due to hardware
19:34:38     Target Cancelled Target cancelled (6/40, WDS GRB 34) due to hardware
20:08:03     Target Cancelled Target cancelled (7/40, NGC 7293) due to hardware
20:27:33     Target Cancelled Target cancelled (8/40, AT2024wqf) due to hardware
20:36:19   Observatory Door Observatory Door has opened
20:36:24   Observatory Door Observatory Door has closed (open time 6s)
20:40:10   Observatory Door Observatory Door has opened
20:40:16   Observatory Door Observatory Door has closed (open time 6s)
20:40:20   Observatory Door Observatory Door has opened
20:40:23   Observatory Door Observatory Door has closed (open time 2s)
20:54:59   Telescope Connected Telescope connected (TheSky6)
20:56:05     Target Cancelled Target cancelled (9/40, Jones 1) due to cloud
20:57:29   Telescope Connected Telescope connected (TheSky6)
21:06:44 Session Resuming Session resuming
21:07:29   Dome Opened Dome opened (Opening time 45s, Zigbee 41s)
21:07:31 Session Running Session running
21:07:33   Queue Resumed Observing Queue resumed
21:07:35     Target Started (10/40) Target started (10/40, M31 w/Nova M31 2025-10a?)
21:24:02     Target Completed Target partially completed (10/40, M31 w/Nova M31 2025-10a?)
21:24:07     Target Started (11/40) Target started (11/40, NGC 600 w/AT2025abzu)
21:28:09       Focusing Skipped Foc1 focusing skipped - star is lost (TCF-LSI)
21:44:16     Target Completed Target completed (11/40, NGC 600 w/AT2025abzu)
21:44:20     Target Started (12/40) Target started (12/40, Gliese 65)
21:48:08       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
21:50:40       Focusing Completed Foc1 AutoFocus Completed (Profile No 4)
21:57:36     Target Completed Target completed (12/40, Gliese 65)
21:57:40     Target Started (13/40) Target started (13/40, GCVS HH And)
22:00:51       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
22:03:09       Focusing Completed Foc1 AutoFocus Completed (Profile No 5)
22:05:01     Target Completed Target completed (13/40, GCVS HH And)
22:05:05     Target Started (14/40) Target started (14/40, AT2025md (CV))
22:09:02       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
22:12:24       Focusing Completed Foc1 AutoFocus Completed (Profile No 6)
22:18:23     Target Completed Target completed (14/40, AT2025md (CV))
22:18:28     Target Started (15/40) Target started (15/40, 61 Cyg)
22:20:47       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
22:23:07       Focusing Completed Foc1 AutoFocus Completed (Profile No 7)
22:25:34     Target Completed Target completed (15/40, 61 Cyg)
22:25:38     Target Started (16/40) Target started (16/40, C/2025 R2 (SWAN))
22:25:58     Target Failed (16/40) Target failed due to slew error (16/40, C/2025 R2 (SWAN))
22:39:38     Target Started (17/40) Target started (17/40, GSC 1224:29)
22:44:45       Focusing Skipped Foc1 focusing skipped - star is too dim (TCF-LSI)
22:51:57     Target Completed Target completed (17/40, GSC 1224:29)
22:52:02     Target Started (18/40) Target started (18/40, C/2022 N2 (PANSTARRS))
22:56:15       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
22:59:04       Focusing Completed Foc1 AutoFocus Completed (Profile No 8)
23:08:31     Target Completed Target completed (18/40, C/2022 N2 (PANSTARRS))
23:08:35     Target Started (19/41) Target started (19/41, C/2025 K1 (ATLAS), ToO)
23:13:55       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
23:16:06       Focusing Completed Foc1 AutoFocus Completed (Profile No 9)
23:35:28     Target Completed Target completed (19/41, C/2025 K1 (ATLAS), ToO)
23:35:33     Target Started (20/42) Target started (20/42, C/2025 R2 (SWAN), ToO)
23:40:33       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
23:43:02       Focusing Completed Foc1 AutoFocus Completed (Profile No 10)
23:53:21     Target Completed Target completed (20/42, C/2025 R2 (SWAN), ToO)
23:53:23     Target Missed (21/42) Target's time slot was missed (21/42, NGC 1300 w/SN2022acko)
23:53:25     Target Missed (22/42) Target's time slot was missed (22/42, UGCA 87)
23:53:27     Target Started (23/42) Target started (23/42, SN 2025aarn)
23:57:59       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
00:00:44       Focusing Completed Foc1 AutoFocus Completed (Profile No 11)
00:17:22     Target Completed Target completed (23/42, SN 2025aarn)
00:17:26     Target Started (24/42) Target started (24/42, GCVS GW Ori)
00:35:44     Target Completed Target completed (24/42, GCVS GW Ori)
00:35:48     Target Started (25/43) Target started (25/43, C/2025 K1 (ATLAS), ToO)
00:40:47       Focusing Skipped Foc1 focusing skipped - star is lost (TCF-LSI)
01:01:23     Target Completed Target completed (25/43, C/2025 K1 (ATLAS), ToO)
01:01:28     Target Started (26/44) Target started (26/44, GCVS BL Lac, ToO)
01:01:49     Target Failed (26/44) Target failed due to slew error (26/44, GCVS BL Lac, ToO)
01:01:53     Target Started (27/45) Target started (27/45, Eridanus Cluster, ToO)
01:03:05       SoftSuspend Called Soft Suspend called due to Deteriorating Conditions (too few stars)
01:04:45       SoftSuspend Cancelled Soft Suspend is cancelled due to improved conditions
01:14:36       SoftSuspend Called Soft Suspend called due to Deteriorating Conditions (too few stars)
01:15:15       SoftSuspend Cancelled Soft Suspend is cancelled due to improved conditions
01:17:09     Target Completed Target completed (27/45, Eridanus Cluster, ToO)
01:17:11     Target Missed (28/45) Target's time slot was missed (28/45, Eridanus Cluster)
01:17:13     Target Missed (29/45) Target's time slot was missed (29/45, AT2022vdr (CV))
01:17:15     Target Started (30/45) Target started (30/45, SN 2025wld)
01:19:56       SoftSuspend Called Soft Suspend called due to Deteriorating Conditions (too few stars)
01:20:26       SoftSuspend Cancelled Soft Suspend is cancelled due to improved conditions
01:25:11     Target Completed Target partially completed (30/45, SN 2025wld)
01:25:15     Target Started (31/45) Target started (31/45, GCVS CN Ori)
01:29:52       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
01:31:46       Focusing Completed Foc1 AutoFocus Completed (Profile No 12)
01:39:19     Target Completed Target completed (31/45, GCVS CN Ori)
01:39:23     Target Started (32/45) Target started (32/45, UGC 4316 w/AT2025advo)
01:43:26       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
01:45:38       Focusing Completed Foc1 AutoFocus Completed (Profile No 13)
02:02:36     Target Completed Target completed (32/45, UGC 4316 w/AT2025advo)
02:02:40     Target Started (33/45) Target started (33/45, C/2025 K1 (ATLAS))
02:19:12       SoftSuspend Called Soft Suspend called due to Deteriorating Conditions (too few stars)
02:19:42       SoftSuspend Cancelled Soft Suspend is cancelled due to improved conditions
02:25:57     Target Completed Target completed (33/45, C/2025 K1 (ATLAS))
02:26:01     Target Started (34/45) Target started (34/45, GCVS RR Tau)
02:36:15     Target Completed Target completed (34/45, GCVS RR Tau)
02:36:19     Target Started (35/45) Target started (35/45, UGC 3458 w/SN2025yao)
02:41:34       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
02:43:51       Focusing Completed Foc1 AutoFocus Completed (Profile No 14)
02:58:43     Target Completed Target partially completed (35/45, UGC 3458 w/SN2025yao)
02:58:47     Target Started (36/45) Target started (36/45, NGC 3106 w/SN2025aauj)
03:03:11       Focusing Skipped Foc1 focusing skipped - star is too dim (TCF-LSI)
03:19:57     Target Completed Target completed (36/45, NGC 3106 w/SN2025aauj)
03:20:01     Target Started (37/45) Target started (37/45, AT2025acvr (CV))
03:24:18       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
03:26:47       Focusing Completed Foc1 AutoFocus Completed (Profile No 15)
03:43:44     Target Completed Target completed (37/45, AT2025acvr (CV))
03:43:48     Target Started (38/45) Target started (38/45, 29P/Schwassmann-Wachmann)
04:04:11     Target Completed Target completed (38/45, 29P/Schwassmann-Wachmann)
04:04:15     Target Started (39/45) Target started (39/45, NGC 4710 w/AT2025acfi)
04:08:57       Focusing Skipped Foc1 focusing skipped - star is too dim (TCF-LSI)
04:25:41     Target Completed Target completed (39/45, NGC 4710 w/AT2025acfi)
04:25:45     Target Started (40/45) Target started (40/45, ESO 565-G19 w/SN2025efc)
04:30:27       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
04:33:09       Focusing Completed Foc1 AutoFocus Completed (Profile No 16)
04:50:03     Target Completed Target completed (40/45, ESO 565-G19 w/SN2025efc)
04:50:07     Target Started (41/45) Target started (41/45, NGC 2986 w/SN2025gj)
05:11:51     Target Completed Target completed (41/45, NGC 2986 w/SN2025gj)
05:11:55     Target Started (42/45) Target started (42/45, VV 410 w/SN2025hjz)
05:33:30     Target Completed Target completed (42/45, VV 410 w/SN2025hjz)
05:33:34     Target Started (43/45) Target started (43/45, NGC 4653 w/SN2025mqc)
05:38:03       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
05:40:41       Focusing Completed Foc1 AutoFocus Completed (Profile No 17)
05:57:35     Target Completed Target completed (43/45, NGC 4653 w/SN2025mqc)
05:57:39     Target Started (44/45) Target started (44/45, NGC 5957 w/SN2025fvw)
06:19:22     Target Completed Target completed (44/45, NGC 5957 w/SN2025fvw)
06:19:27     Target Started (45/45) Target started (45/45, T CrB)
06:29:19     Target Completed Target completed (45/45, T CrB)
06:29:21   Queue Completed Job Queue completed
06:29:23 Session Closing Session closing
06:30:18   Dome Closed Dome closed (Closing time 50s, Zigbee 44s)
06:30:35   Dome Parked Dome parked (parking time 10s), Az: 90.0 deg
06:31:24   Telescope Parked Telescope parked (parking time 44s total)
06:31:48   Telescope State Handbox reads 'Scope parked Turn scope off.'
06:32:10   Telescope Switched Off Telescope Power has been switched off via UPB Switch.
06:33:56   Services Stopped Night Services stopped
06:33:59 Session Finishing Session Finishing started (Create Fits Summary, Transfer Files)
06:35:17     Dome (Find Park) Find Park started (Search Az 80.0 to 100.0°, Step 1.0°, Wide)
06:36:14   Focuser1 Focuser1 (TCF-LSI) not accessible (Last valid data at 06:35:13)
06:36:16     Dome Find Park found (Best Park Az 91.0°)
06:36:22     Dome (Find Park) Find Park started (Search Az 89.0 to 93.0°, Step 0.2°, Narrow)
06:37:09     Dome Find Park found (Best Park Az 91.0°)
06:37:15     Dome Dome has been synced at park position (Az 90.0°, Adjustment: -1.0°)
06:37:17   Dome Parked Dome parked
06:40:19   Dome Charging Dome hasn't started re-charging after 3.1 minutes
06:40:21 Session Finished Session Finished
 
Session Alerts & Alarms
Time     Type       Name Detail
18:45:45 Red Alarm Dome Closing Dome closure hasn't finished after 60s (ShutterState=Closing)
18:47:35 Red Alert Dome Alert Dome hasn't reached 'Closed' state after 120s during SoftSuspend
18:50:40 Red Alarm Dome Closing Dome closure hasn't finished after 60s (ShutterState=vcNull)
18:51:45 Red Alert Dome Alert Dome hasn't reached 'Closed' state after 120s during SoftSuspend
06:36:14 Red Alert Focuser1 Focuser1 (TCF-LSI) not accessible (Last valid data at 06:35:13)
06:36:59 Green Clear Focuser1 Focuser1 (TCF-LSI) is accessible again. Outage was 105s
06:40:19 Red Alert Dome Charging Dome hasn't started re-charging after 3.1 minutes
 

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Operational Issues (2025-11-20 S1375)

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Critical Issues

Major Issues

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Fig 1.  TheSky6 Comet Input Limitation

Cometary targets are normally acquired during observing sessions using the coordinates calculated in realtime by TheSky6.   The interstellar comet 3I/ATLAS (C/2025 N1 (ATLAS)) however has a very high eccentricity (6.1395878) and can not be imported in TheSky6, which requires eccentricty to be a number between 0 and 5. The comet will be acquired during a future session based on explicit RA/Dec coordinates obtained from online calculation sources:
 https://theskylive.com/c2025n1-info


Image

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Investigation - Failed Dome Closure (shutter only 80% closed)

Issue: A requested dome closure failed part way through leaving the shutter only 80% closed (2025-11-20 18:48).

Description.

Time line covering period 18:38 to 20:54 is listed below

Analysis

Dome Closure failures but rare but they have been seen before and when they occur it invariably leaves the shutter in the 80% closed position.  This likely points to a common cause associated with the Shutter/Shutter Motors and Shutter Controller.  

Earlier investigations were

There are two problems that require analysis on this occasion.

 Problem 1 - Failure of shutter to fully close at 18:44:46 - 18:45:45

Since shutter normally takes 45s to close and was left around 80% closed, this suggests analysis should focus on a point around 36s into the shutter closure (from 80% x 45s)

Analysis of the Dome's ASCOM log file show that immediately before the start of the closure the battery level was 97% with current -2 mA (voltage 14.983v). The first 36s of the closure were normal:   battery current immediately rose to -853 mA (voltage 14.082v), shutterstatus value changed from 0 (Open) to 3 (Closing) but then progressively fell as through 700-440 mA (volatge 14.18-14.35v) (as momentum and gravity took over ? ) and by 35s into the closure the battery current had fallen to -305 mA (voltage 14.513v). 

At 36s current was -322 mA (voltage 14.513v). From this point onwards and for next 2.5 minutes the battery values reported in the log file remained static and ShutterStatus value continued as 3 (Closing).  The log finishes at the point that the Dome Connection was closed in preparation to reset the Dome Controller.

18:44:44.287 CommandString RX 264.9 0 0.000000 264.9 0 0 970 14983   -2 54217 1776 2342 0 0
18:44:45.006 CloseShutter Request sent
18:44:45.279 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14983   -2 54217 1776 2342 0 0
18:44:47.245 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14983   -2 54217 1776 2342 0 0
18:44:48.243 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14082 -853 54217 1776 2341 0 0
18:44:49.227 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14071 -865 54217 2025 2340 0 0
18:44:51.195 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14136 -766 54217 2025 2339 0 0
18:44:53.175 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14180 -711 54217 2025 2338 0 0
18:44:54.180 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14147 -639 54217 2025 2337 0 0
18:44:55.183 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14183 -701 54217 2025 2336 0 0
18:44:58.191 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14192 -683 54217 2274 2335 0 0
18:44:59.203 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14236 -545 54217 2274 2335 0 0
18:45:00.204 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14230 -648 54217 2274 2334 0 0
18:45:03.246 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14246 -507 54217 2274 2333 0 0
18:45:04.242 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14257 -500 54217 2274 2332 0 0
18:45:05.246 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14301 -562 54217 2523 2331 0 0
18:45:08.421 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14282 -616 54217 2523 2331 0 0
18:45:09.406 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14281 -489 54217 2523 2330 0 0
18:45:10.393 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14295 -561 54217 2523 2329 0 0
18:45:13.348 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14352 -437 54217 2523 2328 0 0
18:45:14.330 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14357 -432 54217 2523 2328 0 0
18:45:16.333 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14422 -414 54217 2523 2327 0 0
18:45:17.347 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14417 -435 54217 2772 2327 0 0
18:45:19.378 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14446 -432 54217 2772 2326 0 0
18:45:21.382 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14471 -384 54217 2772 2325 0 0
18:45:22.388 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14515 -305 54217 2772 2325 0 0
18:45:23.390 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14513 -322 54217 2772 2324 0 0
 
18:45:24.405 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14513 -322 54217 2772 2324 0 0  - frozen here
18:45:26.410 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14513 -322 54217 2772 2324 0 0
18:46:24.885 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14513 -322 54217 2772 2324 0 0
18:47:24.375 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14513 -322 54217 2772 2324 0 0
18:47:43.577 CommandString RX 264.9 0 0.000000 264.9 0 3 970 14513 -322 54217 2772 2324 0 0

It appears that telemetry with the Shutter was lost at 18:45:24. This point at around 36s into the closure corresponds to the estimated time that the shutter would have reached 80% closed. This can't be coincidence and must be related in someway.

The log doesn't show any anomalous draw of high current draw (potential created by high motor torque?) at around 36s but as telemetry was lost at this point any evidence of such a situation hasn't been caputured.

Although it is rare to happen (no stats compiled but its probably no higher than 1 in 100 CloseShutter requests), when a dome closure fails it is always at around 80% position. This can't be coincidence and likely suggests a mechanical situation, most likely when the bolt on the attaching the shutter to the shutter drive belt goes over the lowermost wheel. in the dome roof.   Unclear if there is a relationship to temperature & ice.  Anecdote data suggests there might be a connection with colder weather.

It is conjectured that in the event of certain higher current spike or motor torque the detected by the Shutter Controller Electronics or firmware that immediately stops the Shutter Motor and in process stops the telemetry with the Dome Controller.  The presence of reasonable battery levels when the Dome was eventualy reconnected doesn't suggests that the shutter motors had been running continuously for 3-4 minutes or more.

There is no evidence that dome controller somehow aborted the shutter closure and closed down telemetry with the shutter. That makes no sense. There is no evidence in the logged that it was aware of any mechanical/electrical issue that the shutter was suffering.

Problem 2 - Failure of the close shutter command at 18:49:35 (following the Dome Controller reboot at 18:48:05)

The ASCOM log shows  Dome connnection was initialised at 18:48:26 after which a series of 'CAN do' responses were provided (likely in response to queries from DeviceHub.Dome), one of the these was Get CanSetShutter which gave the unexected response FALSE

  18:48:27.941 CanSetShutter Get false (Shutter battery low)

the FALSE response is unexpected because the Pulsar Dome System I have normally has CanSetShutter = TRUE and is normally capable of opening and closing the shutter. So a respone of FALSE is highly anomalous.  The reason why it is False is provided, but the explanation given '(Shutter battery low)' seems unlikely at first sight, since battery levels earlier 97% slightly earlier (18:45:23) and were 96% slightly later (18:48:29)

However its understandable when looking at the immediately prior lines in the log file that describing dome and shutter value like the following

   18:48:27.285 CommandString RX 264.9 0 0.000000 0.0 0 0 0 0 0 0 0 0 0 4

here the battery levels appears to be 0% (voltage 0v).   So it is probably that this apparent low battery level is why the dome driver communicated to DeviceHub.Dome that CanSetShutter=FALSE.

Whilst Dome Controller subsequently performed a hand shake with the Shutter shortly after and received new information that showed the battery level of 96% (voltage 14.955v), the CanSetShutter=False response had already been sent to DeviceHub.Dome  less than one second beforehand.

  18:48:28.276 CommandString RX 264.9 0 0.000000 0.0 0 5 960 14955 -3 0 1776 2352 0 0


The dome log doesn't show a CloseShutter request being made from the Client program at 18:49:35.  but the exception  "Method ASCOM.DeviceHub.Dome CloseShutter is not implemented in this driver") was recieved by the client. The exception is presumed to have come from DeviceHub.Dome as it it had previously ascertained that CanSetShutter=False at 18:48:27 and had to reason to think this had changed, though conceptionally it had. (the dome driver knew by 18:48:29 that the shutter had sufficient battery to operate the shutter

It is conjectured that the delay between resetting the Dome Controller and making the connection (21s) wasn't longer enough, for the dome controller to perform a handshake with the Shutter Controller and established its battery condition and shutterstatus.  A longer delay is required (prehaps of at least 30s or more to be certain)

Conclusions

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USBTreeView - V4.6.4

Introduction
USBTreeHub is an application  for displaying a Tree View of the USB Ports and Devices on a Windows PC, and getting information about each item.
  (see  https://www.uwe-sieber.de/usbtreeview_e.html

At the suggestion of the Pegasus Astro Support Team the UsbTreeView application (V4.6.4, x64) was downloaded and installed, to help with diagnosing an issue whereby PegasusAstro USB Control Hub (UCH) couldn't be seen by client ASCOM programs or by Unity Platform UI after restarting the AllSky/Weather Computer.

Whilst UsbTreeView hasn’t yet been used for that precise purpose,  a baseline USB Tree View picture for the AllSky/Weather Computer has been captured and  is shown in the section below.

The program was also installed onto the Observatory Computer on 2025-11-22 and the equivalent baseline USB Tree View picture for the Observatory Computer is shown below.

AllSky/Weather Computer - USB Tree View (2025-11-20)
Running the USB Tree View application on the AllSky/Weather Computer on 2025-11-20 showed the tree view diagram below.

The PegasusAstro USB Control Hub is present on Port 2 of the 'USB Root Hub (USB 3.0)' 

The Control Hub is shown with 7 ports :   Port 1 to Port 6 are the 6 USB ports used by the user on the front of the Control Hub, whilst Port 7 (Pegasus Astro USB Control Hub revA) is for the built-in USB Serial Port (COM4) which is used by the Unity Platform for controlling the USB ports on the Hub .

Image
Port 1 is connected to the Starlight Xpress CCD (Oculus Camera)
 
Port 2 is connected to the Eaton UPS 0463-L (Eaton UPS)
 
Port 3 is connected to Prolific USB-to-Serial Comm Port (COM3) which in turn connects to the CloudSensor Head (CloudSensor)

Port 4  is connected to HD USB Camera Composite Device (referred to as 'HD USB Camera' on the computer) (ObsCam)
  (Port 4 was observed to go off / come on in the UsbTreeView in line with operations in the AstroObsCam program turning off/ turning on the web camera).

Port 5 appears at first site to be not connected to any device,  but is actually cross-referred as Port 5 on Port 14 of the  'USB Root Hub (USB 3.0)' , which has Western Digital Passport 260D USB Mass  Storage Device / Disk Drive - Disk 1 - 5 TB - "Drive" - G:\.   (G Drive)
(when the 'Western Digital My Passport' is clicked a pink colour flag appears against Port 5 on the USB Control Hub )

Port 6 appears to be not connected to any device, but it the USB 6 (Ekowitt Station) is in fact connected to a Ekowitt Gateway Hub which draws 5V power from the Control Hub, but doesn't pass any data, and this explains why no device is shown in the UsbTreeView against the Port.

Observatory Computer - USB Tree View (2025-11-22)
Running the USB Tree View application on the Observatory Computer on 2025-11-22 showed the tree view diagram below.


Image

The PegasusAstro UPB v3 box on the Observatory Telescope is present on Port 1 of the 'USB Root Hub (USB 3.0)' 

The UPB is shown with 7 ports :   Port 1 to Port 6 are the 6 USB 3.0 ports used by the user,
whilst Port 7 (Espressif PegasusAstro UPBv3 USB Composite Device ) is for the built-in USB Serial Port (COM10) which is used by the Unity Platform for controlling the USB ports on the UPB box.

There seem to be multiple discrepencies amoungst the user ports. These can be readily be explained. It seems that either :

The 7-Port USB Hub in the Observatory Computing Bay is present on Port 2 of the 'USB Root Hub (USB 3.0)' 

The Hub has 7 ports, all 7 ports are available for the user.

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This Web Page: Notes - Session 1375 (2025-11-20)
Last Updated : 2026-01-01
Site Owner : David Richards
Home Page : David's Astronomy Web Site