  SNO+ is a neutrinoless double beta decay and low energy neutrino experiment
located in Sudbury, Canada. To improve our understanding of the detector energy
resolution and systematics, calibration systems have been developed to
continuously monitor the optical properties of the detector, such as:
absorption, re-emission, scattering and timing. A part of this in-situ optical
calibration system is the Embedded LED/Laser Light Injection Entity (ELLIE). It
consists of three subsystems: AMELLIE, SMELLIE, TELLIE. The attenuation module
(AMELLIE) is designed to monitor the total optical attenuation, whereas the
optical scattering over a wavelength range of 375nm -- 700nm will be
characterized by the scattering module (SMELLIE). The timing module (TELLIE)
aims to measure the timing characteristics of the photomultiplier tubes. We
present the planned commissioning of these three systems, the running of which
began early 2017.
