Pearl Communications Digital Voice & Data Logger (DVDL) is specifically designed for demanding applications. It uses a state of the art rugged server with 16-channel Line Interface cards to provide recording capability for up to 32 audio channels in 3U high chassis. Built-in redundancy of the critical components coupled with ruggedized design makes DVDL well suited for critical applications requiring 24/7 operation. The DVDL is capable of interfacing and recording AN/TPX-42 Radar video data via an optional RS-422 interface using the HDLC protocol. Additional data interfaces and protocol support can also be provided.

Since voice and data recordings play such an important role in Air Traffic Control , Command & Control, Home Land Security and many other applications, every effort has been made to enhance and improve the quality of recorded audio and data. Audio compression formats available on the market range from 1:1 (16-bit PCM, no compression) to 15:1 (Real Audio). A higher degree of audio compression though reduces storage requirements, however, it results in degradation of recorded audio quality. Archives created on systems that prioritize the reduction of storage requirements at the expense of audio quality may not be justifiable for demanding environments. During investigations, the quality of recorded audio/data become even more important. The DVDL utilizes low noise differential amplifiers with 16-bit linear digitization and voice compression as per CCITT G-729B to reduce storage requirements without sacrificing the quality of audio. CCITT G-729 encoding scheme has the second highest audio quality Mean Opinion Score (MOS) of 3.92 for speech signals. CCITT G-711 u-law 64 Kbit/s encoding scheme (if recorded without any additional compression) has the next highest MOS score of 4.1. Differential amplifiers reduce common mode line noise pickup, hum and intra-system ground noise, and therefore, help increase signal to noise ratio (Typical value achieved is 60 dB). Smart Audio Noise Discrimination (AND) scheme prevents recording of extraneous noise and the resulting wasted storage space. Therefore, DVDL provides the best cost effective recorder system, a solution which is especially suitable for applications where reliability, quality of voice/data, efficient use of recording media and economy are critical.