The following keys are used to define a AMBER setup:
INS.GRAT1.NAME: PRISM, GMR (medium-resolution), GHR (high-resolution)
OCS.OBS.SPECCONF: spectral configuration (Low_JHK, Medium_K_1_2.1 for ex.)
The central wavelength INS.GRAT1.WLEN is also checked to associate the P2VM to the SCIENCE_FRINGE
A P2VM has to be taken at most 4 hours (.17 days) before the science/calib OB,
A calibrator is valid for -1.2/+1.2 hour (.05 day)
In the "nok" case the time is given in days