David's Astronomy - Notes 2019-01-22 (S00649)

Two focusing profiles created during the session.

Focus Profiles, including new HFD measurements

Focusing attempt prior to Target 13/40 A (NGC 201)
i) Best Focus position was visually interpreted at a different position
(~ 4300) and the Focus Offset was manually entered on this occasion
ii) Focus Profile took nearly 6 minutes to complete and
should have been aborted by the program due to dimness of star
iii) The Inner HFD Focus Line is invalid and should not have been drawn

Re-focusing prior to Target 32/43 A (GCVS GK Per)
Excellent Profile, HFD data allows well Defined Inner & Outer focus lines

Issues

Inner and Outer HFD Line Fits should only be drawn within Graph Limits . Code to do this is difficult but potentially feasible
Fixed 2019-01-23 (AstroMain Code modified to only plot line within graph area)
Execution of Focus Profile should have been aborted. A tough call, but focus profiling of ahead of target NGC 201 should probably have been aboretd Working with a dim star and 3 sec exposures x out of first 12 images failed to show any recognisable inventory star At one time the routine would have aborted ok but code changes were recently made to prevent focus run aborting on the final or penultimate target.
>> Code to be reviewed and any appropriate fixes made.
Where there is insufficient data to produce a good quality inner or outer line, then line should either not be drawn or the default gradient line (if
gradient is available) should be drawn as a dashed line through the largest HFD point (usually the first or last point as appropriate)
>> Extend code for drawing of inner and outer limit lines
Where there is insufficient data to produce a good quality inner or outer line, then line should either not be drawn or the default gradient line (if
gradient is available) should be drawn as a dashed line through the largest HFD point (usually the first or last point as appropriate)
>> Extend code for drawing of inner and outer limit lines

Incident & Key Events

Checking the Observatory in the morning at 07:47 revealed that the dome shutter was unexpectedly still open and pointing to NE
Logging on remotely to observatory computer at 07:49 showed an Microsoft .NET Framework Error Message "Unhandled exception has occured in your application". AstroMain program interface was seemingly frozen, CCDSoft was running, TheSky6 seem to be running ok (no ASCOM / TheSky errors messages showing. UPB was displaying a pop-up dialog box, but it was hidden from view.
Dome was commanded to Park using POTH.Hub at 07:49, but it then locked up before commanding it to close the shutter.
Observatory was visited at ~ 07:52 .
- Dome had moved to Park Position but was still open.
- Scope was running and pointing to the NE Sky. Cables position were normal (ie no cable snags etc)
- There was no damage to equipment (skies had been clear for the additional 2.3 hours that the shutter had been remained open)
- Dome Controller was functioning
- Relay function from CloudSensor is presumed to have been active and operating ok
AllSky/Weather computer was running and actively sending weather and cloud sensor data to Observatory computer throughout

Analysis

ASCOM Logs shows that POTH.Hub was in communication with the Dome up until the POTH.Hub closed or killed at 07:50.
It show that dome was moving in 1° steps between 05:30 and 07:45 (indicating that it was actively slaved to the motion of LX200 which must have been still tracking at sidereal pace since its ealier slew to GCVS Z And
(ASCOM logs show that the dome was as Azim 43° at 07:49 , TheSky shows that Z And lay at Azim 42° 20' at this time, confirming this conclusion)
The session (monitor).dat file shows that the Observatory Monitoring thread continued to run ok until 07:59 when AstroMain program was terminated
Report Log shows normal behavior up until the start of Session Shutdown at 05:38, at which point the Obs.Manager appears to have stopped functioning (probably due to a Unhandled Exception of some kind) before initiating closure of the shutter (No Close Shutter reporting or action)
Relay protection to Close Shutter had evidently not kicked in the time the observatory was visited and the Shutter Closed via the Dome Controller's panel & keypad
CloudSensor head was set to relay alerts at following threshold (Clarity/Sky 20, Rain 1, Light 10)
Data files show that Light reached a value of 10.1 at 07:48:48.
This should have trigger a relay alert, which the Dome Controller should have then actioned 10s later at 07:48:58

Coincidentally this is precisely around the time that Dome was commanded to Park via remote operation of POTH.Hub after which POTH .Hub was terminated. It is possible that these actions had inadvertently interferred with the Relay operation in someway

During a daytime test at 12:28 in which the shutter was commanded to open it was evident that the Relay protection was not operating.
CloudSensor Relay was 'Unsafe' yet the Shutter was allowed to open fully (rather than shut at a point 10s into opening)

Checking the Dome's Relay settings showed that Polarity was set to NO (which is the correct setting for my relay configuration). After playing around setting Polarity to NC and back to NO, performing a power cycle on the Relay's Power Supply, and setting relay thresholds for Light to Disabled and then back to enablsed, it was confirm that Relay Protection was again active and correctly working (Shutter Can Open when Relay is 'Safe', Shutter Closes when Relay is 'Unsafe')

So why was Relay protection seemingly not working when first tested and apparently also not working at 07:49 when Light levels exceeded the safety threshold . Power to Dome Controller was turned off when the Encoder Arm spring was replaced 4 days beforehand (on 2019-01-18). Had this upset things ?

Risks & Risk Preventation

Cable Wrap/Equipment Damage. If the scope had been in NNW sky at time of incident the scope could have continued tracking beyond N position and led to wrapping of cable around the pier/mount leading to damage to equipment.
Extra protection has been added to AstroGuard.
Equipment damage from Rain. There was no danger in this particular case as there was a robust weather forecast with clear/dry conditions.

Should the Weather Conditions deteriorated though, either AstroGuard or Relay Protection should have kicked in to close the Dome when AstroMain's Obs Manager had stopped working. On this occasion neither would have operated and provided protection
- AstroGuard program had not been launched for this session
- Relay Protection was not working for some reason

>> AstroGuard should always be operating whilst a session is in progress
>> Relay Protection should be checked regularly and ideally before the start of each session
Relay Issue resolved (date ??) by changing the relay configuration & settings.

Time Line

Time		Event
17:42		Session started
00:30		Unattended operations from 00:30 onwards (weather forecast clear for next 18 hours)
05:30		Started Target 30/31 GCVS Z And (Azim 19.8° Alt 19°)
05:37		Completed Target 30/31
05:37		Skipped Target 31/31 (Failed due to Airmass Limit)
05:38		Queue Completed (Telescope Azim 21° Alt 20°)
05:38		Closing Session
05:38		Shutdown Begun
05:38?		Program Exception probably appeared at this point
05:38		Absence of report lines introducing the 'Close Shutter' routine
05:38 to 07:45		Telescope continued tracking. Dome continued slave motion (Scope and Dome gradually moved from Azim 21° to Azim 43°)
07:47		Checked Observatory. Noticed that Dome was open and not parked
07:49		Logged in. Collected Lock-Down data (Shutter at Azim 43.0)
07:50		Parked Dome (using POTH.Hub Controls)
07:53		Visited Observatory. Closed Shutter (using Controller). Parked Scope (using Autostar II Keypad)


	Session Aims & Highlights
	- Observing Result - Night Summary Plot - Session Event Log

	Operational Issues
	- Critical Issues (1), Major Issues (3), Minor Issues (3), Continuous Improvement (6)

	Investigation - Failure to Close Shutter and Park Scope at end of Session S649

	Images from 2019-01-22 >>

Time	Event	Detail
22:21	Target Started (30/42)	Target started (30/42, GCVS RX And)
22:21	Critical Conditions Alert	Critical Conditions Alert (Obs.Manager will close the Shutter
22:22	Target Aborted (30/42)	Target aborted (30/42, GCVS RX And) due to cloud
22:22	Session Suspended	Session suspended
22:23	Shutter Closed	Shutter closed (closing time 48s)
22:24	Session Resuming	Session resuming
22:25	Shutter Opened	Shutter opened (opening time 45s)
22:28	Target Started (32/43)	Target started (32/43, GCVS GK Per)

This Web Page:	Notes - Session 649 (2019-01-22)
Last Updated :	2023-11-26
Site Owner :	David Richards
Home Page :	David's Astronomy Web Site

David's Astronomy Pages
Notes - Session 649 (2019-01-22)

Session Aims & Highlights (2019-01-22)

Operational Issues (2019-01-22, S649)

Autofocussing / HFD Profiles

Investigation - Failure to Close Shutter and Park Scope at end of Session S649

David's Astronomy Pages Notes - Session 649 (2019-01-22)

Session Aims & Highlights (2019-01-22)

Operational Issues (2019-01-22, S649)

Autofocussing / HFD Profiles

Investigation - Failure to Close Shutter and Park Scope at end of Session S649

David's Astronomy Pages
Notes - Session 649 (2019-01-22)