David's Astronomy Pages Notes - Session 625 (2018-09-03)

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Notes (S626)

	Session Aims & Highlights
	- Observing Result  - Night Summary Plot
	Operational Issues
	- Critical Issues (0),  Major Issues (1),  Minor Issues (6),  Continuous Improvement (0)
	Investigation - Scope not slewing to target (Wrong Tracking State)
	Images from 2018-09-03  >>

Session Aims & Highlights (2018-09-03)

Main aims

1. Targets. Acquire images for a selection of variable stars, nearby stars and deep sky targets
2. Software. Test fixes & modifications made to the Observatory Control Program (CCDApp2) since the last session
3. Stability. Continue checking stability of the Observatory System 

Equipment & Software

•  12" LX200 and ST-10XME
•  80mm APO and ZWO ASI 178MC
• CCDApp2, TheSky6, CCDSoft5, PHD2,  POTH Hub

Highlights

• Targets. Images were successfully acquired from 13 targets
• Software. There was one significant problem with the Observatory Control Program CCDApp2 occurred when trying to make a slew with the 'wrong tracking state' which caused the job queue to lock up/freeze .  (However on the positive side the program was able to go on to safely close the observatory and park the dome and telescope ok at the end of the session)
• Stability. Observatory operations and system were reasonably stable during the session.   There were no problems with Observatory Control Program locking up during manipulation and movement of overlying windows etc 

Summary Plots & Logs

Observing Result (2018-09-03, S625) Observatory Unlocked at 20:50, Operations started at 20:56, Automated Mode from 20:59, Job Queue started at 21:26,  Session Suspended 21:34-21:52, 21:56-22:09, 22:23-22:59,  23:29-00:25 & 02:20-02:43 due to Cloud and/or Rain Forecast Slew Failure at 02:43 (this locked up the Job Queue & prevented further imaging) Obs.Manager intervened to Close Session at 05:33, Parking Scope & Dome  Session finished at 05:35

(Observation Status :  Green=Completed, Yellow= Partially Completed, Red= Failed)

Night Sky Summary Plot - 2018-09-03 Top axis: Sky Brightness at Zenith (in ADU/s) Lefthand axis: Local Time (hh LT). Righthand axis: Sun Altitude (degs)

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Operational Issues (2018-09-03, S625)

• Critical Issues (0)
• Major Issues (1)
• Minor issues (6)
• Continuous Improvement (0)

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Critical Issues

• None

Major Issues

• Scope not slewing to target (Wrong Tracking State) . During the first part of the session that was a slew failure to the 7th target (Hickson 66). The Job Queue executor picked up there had been a slewing discrepancy and ran newly added code to disconnect/reconnect the scope in case there had been a 'Timed out waiting for received data' event (details) to make a second slewing attempt.  TheSky6 / POTH had  put out a dialog box message 'Wrong Tracking State' The dialog' was manually acknowledged (by clicking the 'Ok button') and execution continued. Issue investigated (See Investigation - Scope not slewing to target (Wrong Tracking State) )
  Fixed (AstroMain)

Minor issues

• Autofocusing Failed (no star in image). An attempted autofocusing operation after slewing the 8th scheduled target (NGC 5322) failed when the routine failed to collect the necessary data to define a focus profile and consumed a significant amount of wasted time (5 minutes to get through just 7 out of 20 points before clouded skies suspended the session).  Without any inventory stars in the 3x3 binned Full Frame Image, the routine had no x/y star point to define the appropriate small (150x150 px) box area around the brightest star and no star ADU information to select an optimal exposure. Without the necessary logic to abort the focusing attempt ,  the routine continued on to take a series of full frame 1x1 binned images which were blank of any stars and/or generated an invalid FWHM values from random noise. Autofocussing code modified to test the star inventory (from the initial short full frame image) for an actual viable focus star, and to abort the routine early if one is not found.
  Fixed (AstroMain)

• Guiding continued whilst shutter was being closed.  (Guiding should be stopped first)
  Fixed (AstroMain)
   
• Scope moving whilst image was still being taken (long star trails across image #625019)
   (Imaging should be stopped before scope slew or slew delayed to after exposure has finished
  Fixed (AstroMain)
  
• An inappropriate prior comment  "Re-opening Dome" still visible in the 'txtCurrentFrame' field whilst the shutter was closed and not actually being opened (output of Observatory Manager comments and superposition should be reviewed)
  Fixed (AstroMain)
   
• Problem initiating Build Schedule' from the Observatory Control Program. Schedule building has to be manually initiated from within the Observing Database Tool (sqlform2) instead.
  Fixed (AstroMain/AstroPlan)
   
• Bug in the VMA part of AstroMain (CCDApp2).   Start Analysis  stops before analysing FIT files when running VMA2 analysis on 2x2 binned images after running analysis of 3x3 binned directly beforehand. Output would normally be appended to the first output file
  (is the file getting closed properly after its first access?). Running analysis after changing the output file name (or changing the VMA mode which also changes output file name in the process ) works ok. Attempting to save the first file after changes with a text editor afterwards produced a 'Sharing Violation occurred whilst accessing file' error message until the CCDApp2 program was closed.
  Fixed (AstroMain)

Continuous Improvement

• None

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Investigation - Scope not slewing to target (Wrong Tracking State)

Issue:  Scope not slewing to target (Wrong Tracking State)

Description: During the first part of the session that was a slew failure to the 7th target (Hickson 66). The Job Queue executor picked up there had been a slewing discrepancy and ran newly added code to disconnect/reconnect the scope in case there had been a 'Timed out waiting for received data' event (details) to make a second slewing attempt.  TheSky6 / POTH had  put out a dialog box message 'Wrong Tracking State' The dialog' was manually acknowledged (by clicking the 'Ok button') and execution continued.

Report File (from 1st incident)

  Hickson 66  (7/38)                    2018-09-03 22:59  (Local)
  Observing Program:          Ok        Hickson Groups    (ID: 13)
  Target:                     Ok        Hickson 66        (ID: 465)
 
  [ non relevant lines removed ]

  Checking Coordinates ...    Ok        J2000 Coords      RA: 13 38 33.497, Dec: +57 18 15.32
  Slewing ...                 Ok        
  Waiting for scope...        Ok        17.0s
  Checking Dome Position ...  Ok
  Scope Position Check..      Fail      Scope isn't pointing to the target (Ang Sep. = 42.1 arc degs)
  Checking Slew Issue...      Info      Possible 'Timed out waiting for received data' problem

  Trying Reconnection Fix...
  Disconnecting Scope...      Ok
  Reconnecting Scope...       Ok
  Telescope Coords...         Ok        Az: 271.1, Alt: 24.4
  Slewing(2) ...              Ok        
  Scope Position Check..      Fail      Scope is not pointing to the target (Ang Sep = 42.1°)

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TheSky6 / POTH - 'Wrong Tracking State'

During the second half of the session (and after retiring to bed) there was a further slew failure at 02:43 whilst attempting the 25th target in the schedule. Again a dialog message appeared  'Wrong Tracking State'.  Since the message couldn't be acknowledged /cleared by the Observatory Control program itself, the Job Queue locked up (waiting for POTH to complete the slew).  Operations were then held in limbo until 05:12 when the Observatory Manager intervened to close the shutter  due to cloud and to close the session (park dome/scope) at 05:33.  Parking the Telescope was successful because Tracking is set to ON by an ASCOM request prior to parking and because the park operation is commended by an ASCOM call to the POTH.Scope (without involving TheSky6).

Report File (from 2nd incident)

 Observatory Alert                     2018-09-04 02:21  (Local)
 Critical Cloud Conditions:  Alert     Observatory Manager will close the Dome Shutter
 Close Shutter...            Ok        Shutter is Closed (35s)

  
  Checking Conditions...      Ok        Conditions have improved
  Observatory Manager:        Action    Opening Dome again
  Turn On Tracking..          Ok        Telescope Tracking is ON   (<< Tracking Turned On 02:43:10)
  Turn Off Tracking..         Ok        Telescope Tracking is OFF  (<< Tracking Turned Off 02:43:15)
  Open Shutter...             Ok        Shutter is open (34s)
 
  [ non relevant lines removed ]

---

GCVS ER UMa  (25/38)                    2018-09-04 02:43  (Local)
  Observing Program:          Ok        Main Variables    (ID: 12)
  Target:                     Ok        GCVS ER UMa       (ID: 74)

  Including Offset ...        Ok        Offsets           W 2.0, N -2.0 [arc mins]
  Updating Target ...         Ok        J2000 Coords      RA: 09 46 55.133, Dec: +51 51 59.99
  Slewing ...                 (<< Job Queue locked up here, no return from Slew command )

---

Observatory Alert                       2018-09-04 05:12  (Local)
Critical Cloud Conditions:    Alert     Observatory Manager will close the Dome Shutter

---

Session Suspended                       2018-09-04 05:12  (Local)
  Session: 2018-09-03         Info      Session suspended
  Close Shutter...            Ok        Shutter is Closed (45s)

  Turn On Tracking..          Ok        Telescope Tracking is ON

---

Session Closing                         2018-09-04 05:33  (Local)

  Close Shutter                         
  Checking Shutter...         Ok        Shutter is Closed
  Park Dome                             
  Park Dome...                Ok        Dome is Parked
  Park Telescope                        
  Park Telescope ..           Ok        Telescope is Parked
 

Analysis . Issue is similar to the slew failure issue on 2018-08-14,  a command to Turn On Tracking was overturned immediately 5 second later by a command to Turn Off Tracking.

This can occur when a session resumes after being suspended for more than 20 minutes.
(Code in the Observatory Manager's main loop, executed every 5s, watches the Observatory State, Time Since Suspension started and whether Tracking is On/Off.  Believing that the state was suspended , that it was more than 20 minutes since suspension had started and seeing that Tracking was On, it turned in Off )

Attempts to resolve this earlier problem appear not to have worked.

Action:
- Review the logic and sequence of code execution when coming out of suspension. 
- Also update code to ensure Tracking is set to ON, immediately before each slew.

Update:
 Issue has been fixed.

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