The Spirent DLS 400HE is a two wire ETSI HDSL / ETSI SDSL / ITU-T G.shdsl cable simulator which can be equipped with up to two xDSL DLS 5A01 Impairment Generator Modules. The DLS400HE is offered in three pre-configured versions designed to provide an effective partial or complete solution for the simulation of ETSI HDSL & SDSL. As with other Spirent DLS wireline simulators, wireline length, line configuration, and various noise impairments are set using the IEEE 488 or the RS-232 interface. The command language used is based on the Standard Commands for Programmable Interfaces (SCPI) standard (a subset of IEEE 488.2 (GPIB)).