  We summarize the results of BeppoSAX ToO observation of blazars that were
known to be in a high state from observations carried out in the optical or
X-ray or TeV bands.In some of the observed sources, two spectral components
were detected, which are interpreted as synchrotron and inverse Compton
emission, respectively. Fast variability was detected in three sources (ON 231,
BL Lac and S5 0716+714), but always only for the synchrotron component. Most of
the triggers are from optical observations, consequently most of the observed
sources are LBL or intermediate objects. They were in a high state in the X-ray
band, but not in an exceptionally high state. No strong shifts in the
synchrotron peak frequency are reported. This is in line with the findings that
the synchrotron peak frequency is more variable for HBL objects, i.e. sources
that have this peak at higher energies.
