IT-102, IT-108 Simulator-Tester of Е1, Е2 Streams

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     An IT-102 simulator-tester of Е1 streams (a tester hereafter) is intended for a testing of E1 digital stream transmitting paths (a PDH system ) and digital radio relay stations. The testing is effected with a calculation of error rate and other parameters according to the recommendations ITU-T G.821, G.826, M.2100. The inner structure of the streams is not analysed.
    The device enables effecting efficient measurements of a network and a long-term monitoring .
    The measuring results are represented in the form of tables and diagrams.
    Device operation is effected with the help of a graphical interface.
     A IT-108 simulator-tester of streams is intended for testing of E1 and E2 digital stream transmitting paths (a PDH system ) and digital radio relay stations. The principle of operation of the device is analogous to the principle of operation of the IT-102
    The simulator shapes unstructured streams E1 and E2 which are a pseudorandom pulse sequence.

Product specifications Stream E1 Stream E2
Transmission speed 2048 Kbit/s 8448 Kbit/s
Maximum relative error of transmission speed ±25ppm ±15ppm
Used linear code AMI; HDB3 HDB3
Input and output resistance 120 Ω 75 Ω
Interface type symmetric coaxial
Allowable attenuation of an input signal 12dB - Short Haul mode
14dB - Long Haul mode
20dB
Test signal structure Pseudorandom sequence or a loop constant 8 bit
Error rate measurement range from 10-10 to 10-2
Monitoring range (parameter accumulation) from 15 min. to 7 days
Energizing From a power adapter or from accumulator batteries
AC mains voltage 220V ± 20%
AC mains frequency 50 Hz
Mains power consumption (including a charger) ≤ 20 W
Operation time from built-in accumulators ≥ 2.5h
Weight 0.4 kg
Dimensions 87x173x39 mm

Preparation and Turning on of Tester

     Before tuning on the device install the accumulators included into a delivery set into a battery compartment. Connect a power cable of a mains supply unit, connect a supply unit to a mains.
    Press the "ВКЛ/POWER" button to turn on the tester. A static picture will be displayed within 0,5 s. During this time initialization and configuration of internal tester devices occurs.
    The tester transfers into a measuring mode afterwards. A metering table is displayed the appearance of which is shown in fig. 1.

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Figure 1 - The appearance of a measuring mode

    BER - is error rate, Err - an error counting device, Sync - is a skip counting device, FRQ - is the frequency of the clock pulses regenerated during reception.

    While having bit errors a LED flashes for a short time and the tester generates an auditory message (it can be deactivated in the menu of settings). If there is a great error stream an auditory message is turned off automatically.

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Figure 2 - The appearance of a dialog box "selection from multitude" on the basis of
a menu of standard choosing to present reports

    A status line located in the upper part of the display shows the symbols characterising a supply source, an accumulator charge and current time.

    Key Function:
    / < / , / > / - moving of a pointing tool (a dot) over the dialog box options;
    /Отмена/Cancel/ - exit from the dialogue box without any actions
    /Выбор/Choice/ - fulfilment of actions in the chosen mode (for example displaying of a chosen report type).

Reduction of the measured parameters according to the G0.821 standard
No Shorthand name Parameter designation
1 ES Quantity of seconds with errors
2 %ES Second percentage with errors
3 SES Quantity of seconds heavily damaged by errors
4 %SES Second percentage heavily damaged by errors
5 FES Quantity of seconds without errors
6 UAT Time of channel unavailability
Reduction of the measured parameters according to the G.826 standard
No Shorthand name Parameter designation
1 ES Quantity of seconds with errors
2 ESR Frequency of seconds with errors
3 SES Quantity of seconds heavily damaged by errors
4 SESR Frequency of seconds heavily damaged by errors
5 UAT Time of channel unavailability

    A time monitoring is effected using three parameters: error rate, quantity of errors, quantity of skips. A skip may occur while sliding of a received sequence by 1 bit or more or while having a high error rate, or while disappearing of a test sequence of reception. Display error rate corresponds to the maximum value per a single observation period specified on a diagram by one dot of a horizontal axis (a sampling period). A mode of bit error accumulation displays a decimal logarithm of error sum per a sampling period. A mode of skip accumulation is analogous to a mode of bit error accumulation.
    A set monitoring period - 15 min, 1 h, 8 h, 24 h, 7 days.
    While having a power supply blackout the monitoring results are saved in a long-term memory of the tester.

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Fig.3 - The appearance of a monitoring box