• On Wenesday morning (27/03/19) :
  • With Holger and Robert (MPI) , many telescope "park in/park out" operations have been performed in order to refine the positionning in the acces tower and at the elevation locking bolt
    Holger and Robert applied many mechanical modifications on the acces tower to make the telescope park operations very smooth
    ==> Conclusive operations. 

new session of high speed drive tests after issues with Power Supply.

• Tests of emergency stop (with a speed at 25% and 43 % GRB speed) with a modification of the jerk value from 0.08 to 0.2 ==> OK
• Tests of azimuth movements : (-90 to 270 degres)
  • at 60% of GRB speed. ==> Ok for 6 movements
  • at 80% of GRB speed
    • Ok for 4 movements
    • Failures due to resistance  (sur-tension). Breaking modules in failure then reset
    • Ok for 2 next movements
  • at 100% of GRB speed :
    • 3 movements from -90 to 90 ==> OK
    • Temperature of breaking resistance are getting very high (at least the top one) 

After pointing Polaris yesterday, it seems that the zero position of the telescope was incorrect but It's never had been calibrated (zero was equals to parking position towards center of tower).

So I shift the zero position of telescope by 0.869°.

As the consequence the new Parking Position = -0.869° don't be surprised.

We sent a tracking with with RA211,08 and DEC29,52

1st time the goto position of azimuth was sent at +42° and the trajectory requierts  -52° !!! (speed limit of the tracking 0,001 rad/s)

After a cancel the azimuth was sent at -54° !!!

Yesterday we had the same problem with the same RAD/DEC coordinates. -31° and after a cancel +270° !!!

Is it a problem of trajectory with the 1st point positionning or with this coordinates does we need a higher speed in tracking ?

During this 2 weeks we solve this problems:

_ Park In: Sometimes the final locking position was too limit and the "In Position" sensor was lost

During this weeks we solve this problems:

_ Park In: Sometimes the final locking position was too limit and the "In Position" sensor was lost during the locking witch put the sytems in bad state vs safety constaint (we can't unlock if the sensor In Position is not active). So now the final poition is now adjusted dynamically with the difference betwwen motors and encoders to be sure to stop on torque limit. No more problems since this modification.

_ Problem of communication between the 2 main PLC of the Drive. Due to this error randomly the PLC receive a 2ndTracking command after a Cancel Command. An other random error is to receive the Start Tracking before the Goto Position witch gives errors in the PLC sequence. Communication was rewritten between the 2 PLC. No more problems since this modification.

_ Some change were done in Cancel and Emergency Stop sequence.

_ Now the Power and the Intensity of Main Electrical Cabinet can be available in the OPCUA of the Drive.

_ The High speed of west ALS was decreased since sometimes the variator gives overspeed error. The speed are now identical between the two ALS

+ other minors improvement.

Last week we put in sevice the new ALS completly modified:

_ Main System with new reducer.

_ New Speed parameters for Main System (motor is at full speed but due to reducer the spped is slow). Decceleration sensors not installed since the speed is very slow.

_ All the sensors were replaced by new ones (2 logic embedded in each sensor (NC + NO) ) = only one type of sensor in the ALS. Sensor with connector to ease maintenance.

_ All sensor cabling were changed and new ducts were installed to ease maintenance.

_ The damaged cable of the loadcell was welded again and protected (Heat shrink tube + tape).

_ Add mechanical part to protect loadcell cable when opening over the opening position. It's now impossible to damage Loadcell cable.

_ Increase speed of plier. We add a deceleration sensor in each plier.

_ All the sensors support are new to avoid dammage if there is over position due to manual operation.

The ALS is now functionnal with human interface. The system are so slow 180s !!!, They were not integrated into automatic cycles.

Shifters must manage the Opening/Closing of the ALS at the Start/End od telescope operations.

A new error code is ride up if a door is opened during motion (3002).

Installation of the new PLC code and re-initilalisation of the system.

We tracked stars at various zenith angles and changed the Az and Zd offsets, taking images with the PSF camera for each position. After Armand's changes during the day the offset is the same for all Zenith angles.

Star Zd Az
dAz, dZd image

Polaris 61.5 0.7
0, 0 1568923765.fits
0.5, 0 1568923985.fits
0, 0.5 1568924088.fits
0.5, -0.5 1568924324.fits

Eltanin 29.2 327.9
0, 0 1568924558.fits
0.5, 0 1568924683.fits
0, 0.5 1568924747.fits

Benetnasch 66.6 314.7
Vega 15.6 313.8
0, 0 1568925023.fits
0.5, 0 1568925090.fits
0, 0.5

Kochab 57.3 342.0
Sulafat 8.7 299.5
0, 0 1568925265.fits
0.5, 0 1568925420.fits
0, 0.5 1568925485.fits

Alphecca 52.6 283.0
Arcturus 72.2 282.5
Oph Alpha-55 32.2 246.0
Albireo 1.2 229.1
0, 0 1568925734.fits
0.5, 0 1568925842.fits
0, 0.5 1568925917.fits

Nunki 55.8 190.6
Altair 20.2 168.3
Enif 35.7 115.2
Alpheratz 59.0 71.4
Caph 54.8 35.6
Deneb 21.2 33.9
Polaris 61.5 0.7

- CDM images at park out position.
Exposure 100ms.
OARL on.
Leds 255-200-150-100-50-25-10-1

- CDM image  Az=0 Zd=75-70-65-60-55-50-45-40-35-30-25-20-15-10-5-0
 exposure 100ms
OARL on
Leds On 255

Then we track serie of stars, all affected by clouds unfortunately

- Gamma Peg
- Markab
- Vega
- Altair
- Deneb
For each we took 1 image 100ms led/oarl on + 60 1s images led/oarl off
Then we moved by 2 deg on dark region at took 60 1s images
 

We found out a bug in drive repointing that was affecting the image quality in the first seconds after repositionning. It has been correct in drive SW.

Few first images at 5s with LED @1

Tonight, we tracked Vega to test (a correction of) the pointing offset of the Drive.

Around 22:30UTC, we tried different Az offsets of the pointing in the Semi-expert GUI, followed by taking an image with the PSF camera to see the effect of the offset choice.

We tried delta_az = 0.3°, 0.1°, 0.26°, 0.6°. Strangely, we saw some unexpected (much too large) shifting of the spot for delta_az = 0.3° and delta_az = 0.6° (but looked reasonable for delta_az = 0.26°), which appeared quite puzzling to us (see specific Camera Elog here).

After having tracked with delta_az = 0.6°, we stopped again, and selected delta_az = 0.4°. We submitted the command ("Start"). Some seconds after submission, we became unsure whether we used the right field in the GUI where we entered the delta_az values. We hit "abort current action" (to check our previous command), when probably the slewing to the new offset position wasn't finished yet (about 5 seconds after the previous "Start" command). Then, the GUI became stuck displaying "abort current action", and not displaying the field to enter new positions/targets. According to the GUI, the telescope had in fact stopped tracking, but without any possibility to receive further commands.

We restarted the GUI, but the state remained the same, and checked the telescope outside. Then we called the experts, who could solve the problems after some non-trivial intervention.

At parking in, the telescope got stuck at 94.254°. We checked in the container that fuse Q21 went off. We did not see any errors both in the Drive cointainer and the GUI. We texted the experts. After 15 minutes, we pressed again "ParkIn" (without having touched the fuse). After nothing happend in the GUI, we called the experts. They authorized us to switch back the fuse. After that, still heavy intervention by the experts was needed, who finally made the telescope successfully park (fuse was on during all the trials). Thanks to the experts solving the issue at late night!

When parking in the telescope, accidently hit "Shutdown" button instead of "Parkin" in Drive Semi-epert GUI. Nothing seem to happen for minutes despite telling command in progress "Shutdown"

Texted Drive experts, they told to just hit again the correct "Parkin" button.

Near the end of parkin in, procedure got stuck. Drive expert identified fuse Q21 having gone off. Switched back the fuse, acknowledged error, retried park in. Then, tower close. After expert intervention, did close and everything was fine.

Here is the first entry in the DRIVE ELOG logbook

After finishing the normal start-up procedure, we tried to park out by GUI, but got an error (22:30 local time): "MSG_WARNINGPark_Out_TimeOut"

The Drive, FSM and Command Statuses were "Parked", "in parking Area" and "No command in progress," respectively.

We closed&reopend the GUI and "Park Out" three times, but everytime got the same error.

We then send a message to the WhatsApp group of Drive experts (22:32).

Thierry asked us to restart the server on 10.1.8.3 and we killed the corresponding process (ps -ef | grep MOS), but the statuses didn't change (still FSM "in parking Area").

Thierry asked us to press the "General Abort" button, but didn't improve the situation.

After Ino's intervention (probably, we don't know detail), Thierry asked us to restart the GUI and we did so. The statuses got improved (Drive&FSM: Parked, Command: Started). So, we pushed the park out button, but the same error happend.

Ino suspected if the telescope wasn't unlocked by ALS, but we could visually confirm the ALSs unlocked the telescope properly.

Ino found the problem that "the Flywheel interlock says no motion allowed so PLC refuse to do Park out". He wanted to see the screen shot of Flywheel page. But, we could not connect to the server 10.1.200.1 which means the Flywheel PLC is probably down.

Daniel M. asked us to go to UC1 and we went there (23:45). After some discussion between Daniel and Ino, they asked us to try "stop" -> "run" -> "reset" in the PLC (lower white one, in the cabinet opposite side of the Flywheels). But, still there was no connection to 10.1.200.1 (also no two LEDs in the right side of the PLC turned on). See attachment 1, the LEDs were ON when it was working fine. Attachment 2 was taken tonight (the LEDs were OFF).

Daniel M. suggested us to close the shop because we need Koji's help to fix this problem (00:01).

Regarding the problem on the Flywheel PLC (see here), we entered UC1 under the supervision of Daniel M. and Koji (11:16 local time).

First we checked the LEDs of the black Ethernet cable. LINK in green was constantly ON and ACT in orange was blinking.

Then, we disconnected the black cable and reconnected again after 20 sec (11:30). But, the LEDs of the PLC in the right side were OFF.

Finally, we removed the two red power lines connected to the PLC with a screw driver and reconnected again (11:52). The LEDs of the PLC turned ON. The UC1 web page was back (12:08).

Drive GUI stacked due to a wrong shutdown procedure (Jul. 27th 01-02UTC). This was simply a human error.

First, we pushed ParkIn button as usual in the end of the night. We confirmed the telescope was in Locking Position in GUI, but most probably overlooked to check the statuses of access tower and CSS.

Next, we went to the drive container, turn the key into Service mode and pull it out. (Before get into the drive container, we saw the telescope in parking position, but apparently this inspection was not enough.)

Then, we visually found the camera shutter/SIS was not closed/put back (this was also our misoperation). BUT, at this time, we couldn't notice that access tower was open. (Since it was complete dark time, it was not clear to see even using a fully charged flash light.)

After closing/putting back the camera shutter/SIS (visually checked), we inserted the elevation bolt and locked the azimuth properly. Then, inserted the key back and went back to CC.

Finally, we found that the status of access tower/CSS was opened/unlocked. At first we though this was a bug of the GUI, so closed and opened the GUI, but (of course) it didn't change.

Then, we tried to push the parkin button after turning the key into Automatic mode, but the GUI didn't response. So, we contacted to the drive expert at this point (01:35UTC).

Ino asked us to visullay check the access tower and CSS (01:52UTC). After turning the key into Service mode, we confirmed that the CSS seemed to be locked but the tower was indeed open (02:00UTC). We turned the key into Automatic mode and got out the telescope area. Ino successfully locked and closed remotely (02:21UTC). We turned the key into Service mode and closed the shop.

In the late afternoon shifters noticed the semi-expert drive GUI was not updating, several restarts did not help. Checking into the issue with the drive team connecting from remote it was found that the MOS server is not running and cannot be restarted. This issue could not be solved and will be revisited tomorrow, Jan 17, during the day.

Actions applied for solving this issue: (T. Le Flour)

The status is the following

• The MOS OPCUA Server cannot be relauched since the port used by server was not properly released after the last stop.
• We decided to reboot the VM running on TCS02 but after this operation , the concerned port was still in use.
• By using the commend lsof , we relased the port and relaunched successfully the server.
• Actions : releasing the port has been included in the script used to launch the server to prevent such an issue.