Light curve of PKS 2155−304 as seen by the FPMA module of NuSTAR during the observation 60002022012 (epoch 8). The energy range is 3–60 keV and the plotted data are not background subtracted. However, the background rate is always lower than 0.03 counts per second and the background was steady (within 5%) throughout the observation. Each point corresponds to data taken over roughly one orbit, during the time indicated by the red markers.