Count of seconds since last link up that there was:
xTU-C: CRC-8 >= 1 for one or more bearer channels OR
LOS >= 1 OR SEF >=1 OR LPR >= 1
xTU-R: FEBE >= 1 for one or more bearer channels OR
LOS-FE >=1 OR RDI >=1 OR LPR-FE >=1 .
This parameter is inhibited during UAS.