Performance of the digitizer during Pb--Pb 2018 data taking in the operating conditions chosen for Run 3. On the left plot: the lower part of the triggered spectrum of ZNC common photomultiplier in Pb--Pb collisions where the emission of a single $\SI{2.76}{\tera\electronvolt}$ neutron and multiples are visible. The spectrum is fitted to a superposition of gaussian functions whose peak positions $\mu_i$ are related to the neutron multiplicity by the relation $\mu_i=\mu_{1n}\times i$ and their widths by the relation $\sigma_{i}=\sigma_{1n}\sqrt{i}$, where $i$ is the neutron multiplicity and $\mu_{1n}$ and $\sigma_{1n}$ are the mean and the r.m.s. of the single neutron peak, respectively. The autotrigger algoritm effectively rejects pedestal events. On the right plot: the arrival time of ZNC common photomultiplier signals w.r.t. the reference ALICE L0 trigger signal.