David's Astronomy Pages
Notes - Session 893 (2021-04-30)

 
Bullet Session Aims & Highlights
 - Observing Result
 - Night Summary Plot
 - Session Event Log
 
Bullet Operational Issues
  - Critical Issues (0),  Major Issues (3),  Minor Issues (7),  Small Defects (2),  Continuous Improvement (6)
Bullet Images from 2021-04-30 >>      [ Local Files >> ]
2021-05-01
Bullet Investigation - JobQueue Freezing during Telescope.Jog

Session Aims & Highlights (2021-04-30)

Main aims

  1. Targets. Acquire images of a selection of variable stars, nearby stars, comets & deep sky targets as allowed by time & conditions

Equipment & Software

Highlights

Notes:

Summary Plots & Logs

Observing Plan
Image
  
Observing Result
Image
   
Dome & Scope Slewing Performance
Image
  
Slew/Centering Performance
Image
  
Guiding Performance
Dec Notes :
Run 5 (black) failed due to cloud/lost star
Run 3 & Run 7 (red) impacted by periods of ineffective Dec guiding
Image
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)
Image   
  
Actual Weather vs Pre-Session Weather Forecast
Image
Image   
  
Session Event Log
Time     Event Detail
21:48:37 Session Monitoring AutoStart monitoring for Live Session opportunity starting between 21:49 & 03:07
21:49:27   AutoStart Waiting AutoStart waiting till earliest start time at 21:49
21:49:28   AutoStart Delayed Session delayed due to cloud
22:16:35 Session AutoStarting Session autostarting (22:16)
22:17:17   Camera1 Connected SBIG Camera Connected (set point -25°C)
22:17:19 Session Created Live Session Created (2021-04-30 S00893, ImageSaveNum: 893001)
22:17:21   Scope Switched On Telescope Power has been switched on via UPB Powerbox.
22:19:04   Services Started Observatory Services started
22:19:11 Observatory (Auto) Observatory placed in Fully-Automated Mode
22:19:15 Session Pending Session pending (2021-04-30)
22:19:17 Session Initiating Session initiating (2021-04-30)
22:19:19   Plan Requested Observing Plan requested from AstroPlan (1.21.6)
22:20:43   Plan Loaded Observing Plan loaded to queue (, Plan ID: 632)
22:20:50   Camera1 Connected SBIG Camera Connected (set point -20°C)
22:20:59   Telescope Connected Telescope Connected (TheSky6)
22:21:09 Session Equilibration Session ready for dome & camera equilibration
22:22:00   Dome Opened Dome opened (opening time 45s)
22:22:16   Equilibration Started Dome Equilibration started
22:27:16   Equilibration Skipped Dome Equilibration skipped by user
22:27:18 Session Running Session running
22:27:20   Queue Started Observing Queue started (17 targets selected)
22:28:54       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
22:32:10       Focusing Completed Foc1 AutoFocus Completed (Profile No 1, wide)
22:34:01       Focusing Completed Foc1 AutoFocus Completed (Profile No 1)
22:34:05       Focusing Started-Foc2 Foc2 Focusing Started (Secondary Scope, using ShCap)
22:36:26       Focusing Completed Foc2 AutoFocus Completed (Profile No 2, wide)
22:38:20       Focusing Completed Foc2 AutoFocus Completed (Profile No 2)
22:38:36       Focusing Checked Foc2 Focusing Check Succeeded
22:39:15     Target Started (1/17) Target started (1/17, GCVS RZ LMi)
22:42:08       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
22:44:01       Focusing Completed Foc1 AutoFocus Completed (Profile No 3)
22:49:11     Target Completed Target completed (1/17, GCVS RZ LMi)
22:51:04     Target Started (2/17) Target started (2/17, NGC 4165 w/SN2021gno)
22:56:17       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
22:58:20       Focusing Completed Foc1 AutoFocus Completed (Profile No 4)
23:07:00   UPB.Switch Restart UPB.Switch has been restarted.
23:14:00     Target Completed Target completed (2/17, NGC 4165 w/SN2021gno)
23:14:02     Target Started (3/17) Target started (3/17, NGC 4227 w/SN2021biz)
23:15:33 Job Queue Frozen Job Queue appears to have frozen at around 23:14 - 23:15
23:20:35   Telescope Disconnected Telescope Disconected (TheSky6)
23:20:41   Telescope Connected Telescope Connected (TheSky6)
23:25:36 Session Suspended Session suspended
23:26:26   Dome Closed Dome closed (closing time 50s)
23:32:19     Target Failed Target failed due To centering error (3/17, NGC 4227 w/SN2021biz)
23:32:21   Queue Aborted Job Queue aborted
23:32:23   Dome Closed Dome closed (closing time 50s)
23:32:26 Observatory (Auto) Observatory placed in Fully-Automated Mode
23:32:28 Session Pending Session pending (2021-04-30)
23:32:30 Session Initiating Session initiating (2021-04-30)
23:32:34   Plan Loaded Observing Plan loaded to queue (, Plan ID: 632)
23:32:39   Camera1 Connected SBIG Camera Connected (set point -25°C)
23:32:45   Telescope Connected Telescope Connected (TheSky6)
23:32:55 Session Equilibration Session ready for dome & camera equilibration
23:33:41   Dome Opened Dome opened (opening time 46s)
23:33:43 Session Running Session running
23:33:45   Queue Started Observing Queue started (14 targets selected)
23:33:48 Session Suspended Session suspended
23:34:36   Dome Closed Dome closed (closing time 51s)
23:35:00 User Intervention User Intervention to start session to clear MakeObservatorySafe flags
23:35:28   Services Stopped Observatory Services stopped
23:36:12   Obs.Manager Started Obs.Manager started
23:36:14   Obs.Overseer Started Obs.Overseer started
23:36:18   Services Started Observatory Services started
23:36:30   Services Stopped Observatory Services stopped
23:36:42   Queue Aborted Job Queue aborted
23:36:44 Program Closed Program closed by User
23:36:46 Program Closed Program closed by User
23:37:07 Session Resumed Live Session Resumed (2021-04-30 S00893, ImageSaveNum: 893019)
23:37:12   Obs.Manager Started Obs.Manager started
23:37:14   Obs.Overseer Started Obs.Overseer started
23:37:18   Services Started Observatory Services started
23:38:46   Services Started Observatory Services started
23:38:55   Camera1 Connected SBIG Camera Connected (set point -25°C)
23:39:03   Telescope Connected Telescope Connected (TheSky6)
23:39:21 Observatory (Auto) Observatory placed in Fully-Automated Mode
23:39:22 Session Pending Session pending (2021-04-30)
23:39:24 Session Initiating Session initiating (2021-04-30)
23:39:31   Plan Loaded Observing Plan loaded to queue (, Plan ID: 632)
23:39:36   Camera1 Connected SBIG Camera Connected (set point -25°C)
23:39:41   Telescope Connected Telescope Connected (TheSky6)
23:39:51 Session Equilibration Session ready for dome & camera equilibration
23:39:53 Session Running Session running
23:39:55   Queue Started Observing Queue started (14 targets selected)
23:39:57     Target Started (4/17) Target started (4/17, UGC 8426 w/AT2021knq)
23:44:23       Focusing Skipped Foc1 focusing skipped - star is too dim (TCF-S)
23:58:47     Target Completed Target partially completed (4/17, UGC 8426 w/AT2021knq)
00:03:26     Target Started (5/17) Target started (5/17, C/2020 T2 (Palomar))
00:13:48 Critical Cloud Alert Critical Cloud Alert (Obs.Manager will close the Shutter)
00:13:50   HardSuspend Called Hard Suspend is called due to Critical Conditions (cloud)
00:13:52     Target Aborted (5/17) Target aborted (5/17, C/2020 T2 (Palomar)) due to cloud
00:13:54   Queue Paused Queue paused For Session Suspension
00:13:56 Session Suspended Session suspended
00:14:43   Dome Closed Dome closed (closing time 50s)
00:14:51     Target Cancelled Target cancelled (5/17, C/2020 T2 (Palomar)) due to cloud
00:28:58     Target Cancelled Target cancelled (6/17, Nova Per 2020 (CV)) due to cloud
00:32:00 Session Resuming Session resuming
00:32:45   Dome Opened Dome opened (opening time 45s)
00:32:47 Session Running Session running
00:32:49   Queue Resumed Observing Queue resumed
00:32:51     Target Started (7/17) Target started (7/17, NGC 5018 w/SN2021fxy)
00:40:23       Focusing Skipped Foc1 focusing skipped - unable to find a star (TCF-S)
00:54:34     Target Completed Target partially completed (7/17, NGC 5018 w/SN2021fxy)
00:54:36     Target Started (8/17) Target started (8/17, NGC 3310 w/SN2021gmj)
00:58:49       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
01:01:03       Focusing Completed Foc1 AutoFocus Completed (Profile No 7)
01:16:38     Target Completed Target completed (8/17, NGC 3310 w/SN2021gmj)
01:16:40     Target Started (9/17) Target started (9/17, UGCA 271)
01:20:08       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
01:22:22       Focusing Completed Foc1 AutoFocus Completed (Profile No 8)
01:53:21     Target Completed Target completed (9/17, UGCA 271)
01:53:23     Target Started (10/17) Target started (10/17, HIP 87937)
01:58:31       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
02:00:22       Focusing Completed Foc1 AutoFocus Completed (Profile No 9)
02:02:31     Target Completed Target completed (10/17, HIP 87937)
02:02:33     Target Started (11/17) Target started (11/17, UGC 11177 w/AT2021koq)
02:04:25 Program Hung Job Queue froze whilst conducting Telescope Jog
02:04:27 Job Queue Frozen Job Queue appears to have frozen at around 02:04 - 02:04
02:09:31   Telescope Disconnected Telescope Disconected (TheSky6)
02:09:36   Telescope Connected Telescope Connected (TheSky6)
02:14:35 Session Suspended Session suspended
02:15:05 Job Queue Frozen Job Queue appears to have frozen at around 02:14 - 02:15
02:15:25   Dome Closed Dome closed (closing time 50s)
03:33:16 Session Closing Session closing
03:33:18   Dome Closed Dome already closed (closed at 02:15, closing time 50s)
03:33:23   Dome Park Aborted Dome Park aborted (0s, Az=156.7degs)
03:33:48   Telescope Parked Telescope parked (parking time 19s)
03:34:00 Job Queue Frozen Job Queue appears to have frozen at around 03:33 - 03:34
03:34:18   Telescope Switched Off Telescope Power has been switched off via UPB Switch.
03:35:09   Services Stopped Night Services stopped
04:22:10 User Intervention User Intervention to dismiss dialog message in TheSky6 to release job queue & ObsManager
04:22:39 Session Housekeeping Housekeeping Started (Cleanup FITS, Create Fits Summary, Transfer Files)
04:22:59 Session Finished Session Finished
 
Session Alerts
Time     Alert Detail
23:07:00 UPB.Switch disconnected UPB.Switch has unexpectedly disconnected. Restart will be attempted
23:07:02 UPB.Switch UPB.Switch has been successfully restarted.
23:25:36 Job Queue Job Queue appears to be frozen (last IamAlive message at 23:14)
02:14:31 Job Queue Job Queue appears to be frozen (last IamAlive message at 02:04)
02:25:07 Job Queue Job Queue appears to be frozen (last IamAlive message at 02:14)
(this is a logic failure,  queue was frozen but it still related to 02:04 event)
03:33:23 Dome Failed To Park Dome at Az 156.7 degs)
(this is a reporting failure, scope did actually park)
03:44:05 Job Queue Job Queue appears to be frozen (last IamAlive message at 03:33)
(this is a logic failure,  queue was frozen but it still related to 02:04 event)

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Operational Issues (2021-04-30, S893)

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Critical Issues

Major Issues

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Small Defects

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2021-05-01


Investigation - JobQueue Freezing during Telescope.Jog

Issue : Job Queue held up by a blocking TheSky6/ASCOM dialog box "Unable to start direct slew" after calling Telescope.Jog causing loss of obsevring time, and eventually leads to the ObsOverseer initiating the MakeObservatorySafe routine, with sideeffects.

Description :
During session S893 there were two separate incidents involving this issue:

1)
Job Queue held up by blocking TheSky6/ASCOM dialog box "Unable to start direct slew" (23:14) .  During Locate Frame1 centering of Target 3/17 (NGC 4227) the JobQueue became held up by a frozen Telescope.jog call which eventually lead to the ObsOverseer initiating the MakeObservatorySafe routine at 23:25.  The problem occurred during a 2.77' S Jog at 23:14:49.48 which followed a 1.79' E Jog at 23:14:46.97 and a 1s settle delay at 23:14:48.46.   Job Queue was released by user interventing and acknowledging the dialog box message in TheSky6.  However after aborting the job it was difficult to successful restart the queue (the shutter kept closing). Eventually got back to starting Target 4/17 at 23:33 (loosing 19 mins of observing time).  A seperate ticket has been added for addition of  'A back door method is required to release flags that cause  'MakeObservatorySafe' to be reactivated'.    

2) Job Queue held up by an assumed blocking TheSky6/ASCOM dialog box "Unable to start direct slew" (02:04).  During Locate Frame2 centering of Target 11/17 (UGC 11177) the JobQueue became held up by a frozen Telescope.jog call .  Problem occurred during a 0.44' W Jog at 02:03:58.  ObsOverseer declared that the JobQueue was frozen 10 minutes later at 02:14. It is unclear if  the MakeObservatorySafe routine was initiated/run. It seems not but this is most likely due to Observatory entering suspended state at 02:14 . (some 90 mins of observatory time were lost)

Analysis

In the past there have been occasional problems with this or very similar issue using MeadeLX200GPS driver with POTH.Hub, but these problems largely went away using MeadeLX200GPS driver with DeviceHub.Telescope.   The issue affected session S888 and S889 badly when using an March 2021 verison of MeadeGeneric driver which had a bug that caused it to never set Slewing property to True, and in particular not setting it to True when the telescope was physically slewing (see Investigation - Jog Execution held up by "Unable to start the DirectSlew" dialog from TheSky6/ASCOM, 2021-04-20) . This prevented automated operations and the session had to be run in a semi-manual mode where the TheSky6/ASCOM dialog boxes was dismissed when it occured, releasing the block and allowimg Job Queue to continue before MakeObservatorySafe was initiated. This bug was fixed in 1.0.1.327 but due to DeviceHub not going immediately over to fast polling when there is a slew or slew request there is seeminngly a residual weakness that makes TheSky6 still prone to the issue occuring occasionally.

1) Case at 23:14 :

Client Log

23:14:46.97 | NGC 4227 Make E Jog Info | W= -1.79' (-2.14' at Dec 33.4)
23:14:48.46 | NGC 4227 WaitOn Scope.Settling Info | Sleeping For 1.0 secs

23:14:49.48 | NGC 4227 Make S Jog Info | N= -2.77'

Slew appeared to take <2s to finish before execution returned from TheSky.Telescope.Jog
(or ASynch is 1 rather than 0)

MeadeGeneric Log

23:14:47.080 SlewToCoordinatesAsync Ra=12.2867840874976, Dec=33.2890143017561
23:14:47.111 Slewing Result = False
23:14:47.376 DoSlewAsync Slewing to target

no slewing messages during this time (some 8 secs)

23:14:55.574 Slewing Result = True
23:14:57.016 Slewing Result = True
23:14:58.232 Slewing Result = True
to
23:15:08.794 Slewing Result = True
23:15:10.884 Slewing Result = False

It is evident that SlewToCoordinatesAsync at 23:14:47.080  is associated with E Jog Call from client at 23:14:46.97 
The log doesn't have any SlewToCoordinatesAsync message associated with S Jog Call from Client

Slew took 8.5s to turn Slewing=True,  Slew took some 21s to finish.

23:14:47.111 TargetDeclination Get 33.2852305555556
23:14:47.111 TargetRightAscension Set 12.2867840874976

DeviceHub log (for TheSky6)

23:14:47.376 SlewToCoordinatesAsync: RightAscension = 12.2867840874976, Declination = 33.2890143017561
23:14:48.453 Get Slewing: False (done)
23:14:48.562 Get RightAscension: 12:17:04 (done)
  to
23:14:49.373 Get RightAscension: 12:17:04 (done)
23:14:49.373 Get Declination: 33[B0] 17' 16" (done)
   gap in messages no Get Ra/Get Dec messages !
23:14:54.646 SlewToCoordinatesAsync: RightAscension = 12.2844006447618, Declination = 33.2419057267208 (failed)

 No Get Slewing: True messages !

(does this failed request produce any exceptions ? that find there way back to client ?)

2) Case at 02:04 :

Client Log

02:03:58.78 | UGC 11177 Make W Jog Info | W= 0.44' (0.45' at Dec 6.8)
02:04:00.37 | UGC 11177 Trace Telescope.Jog Ok | IamAlive: MakeJogCorrection, JogW
02:04:22.72 | UGC 11177 Get Scope.RaDec Fail | Exception in Scope.GetRaDec
02:04:22.72 | UGC 11177 Get Scope.RaDec Fail | Timed out waiting for received data
02:04:31.04 | Observatory Overseer Check JobQueue Info | Task In MakeJogCorrection/JogW is taking a Long time? (Telescope.Jog)
02:09:31.50 | Observatory Overseer Check JobQueue Info | Task In MakeJogCorrection/JogW is taking a Long time? (Telescope.Jog)
02:14:31.96 | Observatory Overseer Check Operation Info | Task In MakeJogCorrection/JogW appears to be frozen (Telescope.Jog)

MeadeGeneric Log

02:03:58.815 Slewing Result = False

02:03:58.878 SlewToCoordinatesAsync Ra=18.2830433880329, Dec=6.55555199894204
02:03:59.252 DoSlewAsync Slewing to target

02:04:00.500 SlewToCoordinatesAsync Ra=18.2847688498846, Dec=6.55520642849791

02:04:06.188 GetSlewing Result = True    (T+7.4s)
02:04:07.290 GetSlewing Result = True    (T+8.5s)

02:04:21.471 GetSlewing Result = False   (T+22.7s)

Notes:
Polling seems very limited between 02:04:08 & 02:04:21 . How much of this is associated with or has same underying cause as the ' Get Declination: (failed) messages received by DeviceHub.Telescope at 02:04:22.7 & 02:04:25.2


There were no slewing messages in the first 6s (ie in the time interval  between 02:04:00.5 & 02:04:06.1)
In fact there were no messages of any kind between 2:04:01.998 &  02:04:05.991  (1.5s), presumably slow polling by DH, frozen job queue,

3)  Control Case : Locate Frame 1 for NGC 4165  (22:51) was associated with 13.18' pointing error so long jogs must be involved.

22:52:11.33 | NGC 4165 Start Jog Info | 13.24 arc mins (W= 6.43', N= 11.57')
22:52:11.36 | NGC 4165 Make W Jog Info | W= 6.43' (6.60' at Dec 13.1)
22:52:26.17 | NGC 4165 WaitOn Scope.Settling Info | Sleeping For 1.0 secs

22:52:27.18 | NGC 4165 Make N Jog Info | N= 11.57'
22:52:41.76 | NGC 4165 WaitOn Jog Info | Sleeping For 1.0 secs
22:52:42.77 | NGC 4165 Finish Jog Ok | [W] [N] Jog Completed


W Jog took 15s to return
N Jog took  14s to return

MeadeGeneric Log

22:52:10.791 Slewing Result = False

22:52:11.415 SlewToCoordinatesAsync Ra=12.2098175517483, Dec=12.9327611237471
22:52:11.695 DoSlewAsync Slewing to target
22:52:14.800 GetSlewing Result = True   / 22:52:14.800 Slewing Result = True         Slewing (T+3.4s)
to
22:52:22.943 GetSlewing Result = True   /  22:52:22.943 Slewing Result = True
22:52:24.643 GetSlewing Result = False /  22:52:24.643 Slewing Result = True
22:52:25.876 GetSlewing Result = False /  22:52:25.876 Slewing Result = False        Slewing Stopped !

22:52:27.230 SlewToCoordinatesAsync Ra=12.2099158320193, Dec=13.1253423561364
22:52:27.496 DoSlewAsync Slewing to target

22:52:29.820 GetSlewing Result = True  /   22:52:29.820 Slewing Result = True        Slewing   (T+2.5s)
to
22:52:39.461 GetSlewing Result = True /   22:52:39.461 Slewing Result = True
22:52:41.567 GetSlewing Result = False / 22:52:41.567 Slewing Result = False       Slewing Stopped !

What is difference between
22:52:41.567 IsSlewingToTarget     IsSlewing = False : result =
22:52:41.567 GetSlewing            Result = False
22:52:41.567 Slewing               Result = False

Attempted Fix (2021-05-01)

Fixed attempted by creating new Scope.Jog routine, calling Telescope.Asynchronous=1 and entering a loop to monitor Scope.Slewing and use it to spot the start and end of slewing before returning, with 2 minute timeout.

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