This reports the highest total received optical power across the whole multiplexed line during the bin. Because this reading is a cumulative, non-resettable running figure tracked only from a single start reference rather than any fixed bin, an elevated line-wide max can flag an amplifier overshoot right after a channel add/drop event, which briefly overdrives every receiver on that fiber. For example, a spike in total OTS power right after a new wavelength was provisioned on this line is consistent with the amplifier's gain loop briefly overcompensating before settling, accumulated since this row's single start reference, with no periodic reset.