Aeroflex 2852/S & 2853/S Digital Analyzers - AEROFLEX - #2

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n x 64 kbit/s Channel Testing The expanding services at n x 64 kbit/s can be tested where they are carried within T1, 704, 2048, 8448 and 34368 kbit/s digital signals. All systems and n x 64 kbit/s cross-connect switches are catered for with the flexibility of contiguous and non-contiguous channel selection. Tributary and Channel Testing 2048 kbit/s tributaries within 8448 kbit/s digital signals and 2048 and 8448 kbit/s tributaries within 34 Mbit/s digital signals can be tested to ensure correct functioning of multiplexes. Unstructured Where the structures on digital links do not conform to the usual ITU-T Recommendations, for example inter-computer links, they can be tested using an unframed format. DATA INTERFACE TESTING All commonly used data interfaces are provided as standard to give a comprehensive data test capability together with primary, second and third order PCM rate testing. Thus PCM and data circuits and equipment can be tested with one compact, fully integrated test instrument, from 50 bit/s to 34 Mbit/s. Data test interfaces provided are RS-232, X.21, RS-449 (V.36), V.35 (2853), codirectional and contra- directional (2852 and 2853). DTE is standard, DCE optional. EUROCOM D/1 is optionally available for European military network applications. Modes Both synchronous and asynchronous modes are possible with a wide range of standard and user programmable data rates, so that traditional data interface testing can be addressed together with modern digital data services at 64 kbit/s, n x 64 kbit/s and other rates. REMOTE LOOPBACK Remote loop activation and deactivation is provided for the RS-232 test interface according to ITU-T recommendation V.54 by means of control lines. This facilitates testing of data circuits automati-cally without the need for manual intervention. FLEXIBLE ERROR MEASUREMENTS Where appropriate, 2852 and 2853 have the ability to detect, simultaneously, Code Errors, Framing Errors, made Pattern Errors and CRC Errors. Further measure-ments are then on a selected error type, including error distribution. Error Distribution/Histogram The results are displayed in the form of a histogram with accumulation over 72 hours, and a maximum resolution of 1 minute. Other events such as sync loss are also stored on the histogram. All stored results are tagged with time and date, so that a comprehensive record of long term measurements is available to assist in fault localisation. A permanent record of results can also be obtained by printing a text equivalent or a facsimile of the histogram subsequent to the test. In addition the instrument can be pro-grammed to Autoprint selected parame-ters on event or at timed intervals. G.821 and G.921 Measurements with Histograms Where availability measurements are being made on 64 kbit/s channels, results in G.821 format will be provided, while for higher rates Annex D of G.821 is applied. In addition up to 100 day histograms are provided for each of the G.821 parameters with automatic recognition of exceeding daily limits, defined by circuit grade and length for G.821, or circuit classification for G.921. Alternatively user defined limits can be entered directly. Where short tests are required histograms can be selected up to 25, 50 or 100 hours with a resolution of 15, 30 or 60 minutes. RESIDUAL BIT ERROR RATE Assessment of background error performance is useful in systems subject to periodic degraded performance, such as radio or satellite systems. This measurement is a long term error rate ignoring severely errored seconds. BURST ERROR CAPABILITY Qualification of Burst Errors within networks, and network performance under burst error conditions is difficult to achieve. 2852 and 2853 provide comprehensive facilities to stress network equipment with test patterns injected with programmable error bursts and burst rates, while on the receive side, different burst sizes can be detected and recorded. Thus, since the errors can be injected at both logic and code level, network performance under burst conditions can be determined. HIGH TOLERANCE TO BURST ERRORS 2852 and 2853 are particularly suited to measurements on systems subject to high error rates and burst errors, with the ability to ride through rapid fades as experienced on digital radio systems. CRC BLOCK ERROR INJECTION TO G.962 2048 kbit/s systems with CRC for ISDN applications can register G.821 parameter events when certain CRC block error rate thresholds are exceeded. The instrument is able to check the thresholds for Severely Errored Seconds, Degraded Minutes and Errored Seconds. The thresholds can be preset for each parameter, and multiplex and other equipment can be quickly and easily checked for conformance to the G.962 Recommendation. ISDN ERROR REPORT BIT MONITORING TO G.962 A further facility for the 2048 kbit/s systems with CRC is to carry information within the Not Frame Word bits 6, 7 and 8, on the occurrence of G.821 events (Severely Errored Seconds, Degraded Minutes and Errored Seconds), and where the events originated. The origin is determined by the position of these bits with respect to the CRC multiframe. The instrument decodes and displays this information in real time or latched mode, and can Autoprint it if required. PROGRAMMABLE ERROR GATING In addition to long term mean error ratio, a current error ratio measurement is available with fixed gating periods of 1, 2, 5 or 10 seconds, as well as automatic gating adjustment. Flexibility of application is thus assured, for example fade margin adjustment on digital radios. IN-SERVICE AND OUT-OF-SERVICE MEASUREMENTS 2852 and 2853 are equally suited to both installation and in-service maintenance measurements at rates up to 34 Mbit/s. Interfaces are provided to enable the receiver to be connected to a number of network points at varying impedances and signal sensitivities.