This standard defines the functional requirements and application protocols associated with traffic data collection stations equipment, both as stand-alone equipment , hereinafter referred to as ETD, and as integrated equipment , hereinafter referred to as ETDI, and intended for use in combination with an universal remote station (ERU). For both ETD and ETDI equipment, the functional requirements of this standard apply in full, with no differentiation between the two variants unless expressly stated otherwise. The application protocols defined here can only be verified in the ETD and not in the ETDI for constructive reasons. NOTE 1 In this version of the UNE 135421-3 standard, the information that the ETD is able to provide to the systems connected to it is extended, considering that the classification of 9 categories based on the German BAST TLS 9 standard is the most appropriate for the categorisation of the Spanish vehicle fleet. This extension of information is intended to provide data that were not included in the previous version of the UNE 135421-3 standard: - Instantaneous vehicle data: o Number of axles, distance between axles, weight per axle. o Electromagnetic profile o Euro9 classification (based on BAST TLS 9 (8+1)). - Instant data on the status of detectors. - Retrieval of historical data for both vehicles and detectors. NOTE 2 From a normative point of view, a single generic equipment is referred to as data collection station (DTS) whether it is a stand-alone DTS or an integrated DTSDI version and unless otherwise explicitly specified.