(1) University of Glasgow, Kelvin Building, Glasgow G12 8QQ, Scotland.
This note describes the performance of the algorithm used to determine and subtract the pedestal values in the TELL1. The algorithm is implemented in the TELL1 boards and emulated in the Vetra framework. This algorithm is performed as the first stage of the Non-Zero Suppressed data processing. Pedestal values determined in the Vetra emulation can be stored and later uploaded to the TELL1s. The time stability of the algorithm is assessed using data taken during commissioning. The monitoring of the pedestal values is also described.