If the robot detects a failure while doing a setup, thus while physically moving fibres, it is essential to apply the following approach, not less and not more:
1) record the sequence with the video recorder (reminder, should be already on)
2) before issuing the command 'af2 recover' make sure the backillumination is switched on
3) use the command 'af2 viewfibre xx' to view the fibre that failed, checking as well the adjacent fibres to either side
4) issue 'af2 recover' ONCE
5) is this not working it's time to SEEK EXPERT ADVICE
  Usually the way forward will be to:
6) bring the t/s to AP3
7) move the prime rotator with the push buttons in such manner that the TV camera (AG) is pointing upwards. This is the best position to separate the fibre module from the robot
8) separate the module using the studs that should be kept in the red trolley on the dome floor. This is a 4 hands job for people who have done this before. The module is quite heave and needs to be separated parallel and smoothly
9) investigate the fibre situation using the AF2 fibre sniffer camera (kept in the AF2 cabinet on the dome floor), cable and monitor (control room) or the mirror (kept behind the tools cabinet on the observing floor)
10) if you detect a problem with the failed fibre, correct the situation by carefully pulling the fibre in the load-ring. Compare the position required with the position of already disabled fibres!
11) switch the backillumination on and check if light (the light is infrared and not visible!) is coming out of the fibre/prism using the AF2 sniffer camera (is there no light the fibre can't be recovered and has to be disabled)

N.B. To check the if the light is coming out of the fibre/prism, you can also use your mobile phone camera.

12) mount the module back on the robot
13 ) before reloading the fibre, check a couple of other fibres with: af2 viewfibre xx, to check that they appear close enough to the centre. This then proves that the module has been put back in the same place, as there is always a bit play on the mounting bolts
14) switch the backillumination on and issue the command 'af2 loadfibre xx'
15) if loadfibre does not recover the fibre you need to 'af2 disablefibre xx'. This bears the consequence that the observer has to produce a new configuration considering the fibre just disabled is not available anymore
16) check all fibres can be found by the robot by running 'af2 loadmodule'
17) check everything is back in place (module, covers, cable ties) and no tools are left behind before moving the telescope to zenith
18) continue with the setup.
 

Last updated 21st May 2015 by Renee Pit