Problem identification

Depending on the problem, you can be able to resolve it. The first thing is to identify the origin of the error. Check the presence of error messages on the different monitor panels, the jlog, ACS and the ACU control panel.

MinorServo

Errors, warning and failure of the MinorServoBoss can be related to the crash of the server that manages the minor servos: MSCU. Check first if the server crashed and restart it if needed. Ask the project friend to complete the procedure from viewer01 (VLBI console). The instructions are on this link: https://srtsupervisoronduty.readthedocs.io/it/latest/sd/srt/procedures/minor_servo.html#mscu-restart.

After restarting the server it is necessary to restart the containers of the minor servos on the discos-manager computer.

Quicklook

If the Quicklook stop running correctly and is frozen to a previous session, you can restart it from a terminal with the user “observer”:

$ su - discos service quicklook restart

Please, ask the project friend to complete the procedure with the password.

Monitor panels

Look at the 9 panels. The error messages usually come out in red.

Attention

operatorInput

Check that the command you have insterted is written correctly. If the error is not related to a typo, try to identify the origin of the problem. Check the different panels (Scheduler, MinorServo, Receivers, etc…) and the jlog.

Attention

Scheduler

srt-scheduler when the schedule is not running correctly. If the Scan/SubScan number is proceeding correctly, the FAILURE can be associated with skipped scans because of the too high or too low elevation of the source (> 85° or < 5°).

Solution: Stop the schedule with > stopSchedule and check the elevation of the target with CASTIA. Then start again the schedule with > startSchedule=[projectID]/[schedulename].scd,[N] when the target is visible.

Attention

Receivers

If the local oscillator (LO) value is set to 0 on the Receivers panel while you have inserted a correct value (in MHz) on the operatorInput, the LO container is probably down (check also the operatorInput and jlog errors). Contact the person in charge of the observations (observer’s friend) to resolve the problem.

Jlog

Attention

LoggingClient

Error messages on the LoggingClient appear in red while warning are in yellow. If the Subscan skipped message appears, the scheduler is skipping subscans because of a too high or low elevation of the target (see previous section).

ACU control panel

If one or different boxes appear in yellow (warning) or red (error), put the mouse on the box and read the associated message.

Attention

Servo DC warning

If the wa_Servo_DC_Warn label appears on the yellow warning box, the observations must be immediately interrupted. Give the following commands to stow the antenna:

> antennaPark

> servoPark

> asPark

Communicate the problem to the person in charge of the observations, as indicated by your project friend.

Attention

Servo system and axis errors

After the stow of the antenna, errors related to the main servo system or to the azimuth/elevation axes may occur.

To solve the problem, give the following commands in the operatorInput console:

> antennaReset

> antennaTrack

Wait 10 seconds. If the errors disappear, you can proceed to the observations by setting first the minor servo setup > servoSetup[code], with [code=LLP,PPP,CCB,KKG].

Instead, if the errors remain, give again the previous commands:

> antennaReset

> antennaTrack

Wait 10 seconds. If the errors disappear, you can proceed to the observations. Please, set first the minor servo setup as indicated before.

If the errors persist:

• push the emergency stop button
• release the emergency stop button

> antennaReset

> antennaTrack

At this point, the problem should be resolved. You can proceed with the observations. Please, set first the minor servo setup as indicated before.

If the problem persits, please contact the person in charge of the observations (observer’s friend).

Attention

Power errors

In the case of err_Power_Error label, look at the jlog window. The MAIN POWER ERROR message should appear, being assigned a CRITICAL priority. To resolve the problem, give the following commands in the operatorInput console:

> antennaReset

> antennaTrack

If the error message is different or the problem still unresolved, contact the person in charge of the observations (observer’s friend).

Wind velocity

Attention

MeteoClient

Check regularly the wind velocity using the $> meteoClient & on a shell of nuraghe-mng. For observations in K-band, the wind speed should not exceed 30 km/h (value to be checked) otherwise the pointing accuracy will probably be lost.

Attention

Unstow of the antenna

The antenna is automatically stowed when the wind speed exceeds 60km/h. If you want to continue the observations without redoing the setup from the beginning (receiver, bandwidth, attenuations, etc…), you can simply unstow the antenna and start again the observations where you left off, following the sequence of commands:

> antennaUnstow

> antennaTrack

> startSchedule=[schedulename].scd,[N] where you were previously.

Stow of the antenna

Attention

Put the antenna in stow with the green button

In the case the control software has some problems or is disable and you cannot communicate anymore with the antenna, you can use the green button to park the antenna. The green button is located close to the red emergency stop button in the control-room.

When the antenna is parked, look at the ACU monitor, wait until Axis blocked appears in red (Fig.37). Only at this moment, you can press on the emergency stop button (Fig.38).