DEVICES OF THE UNIVERSAL TIME SYSTEM

Fields of use: universal time systems in I&C systems; automated systems for measuring, monitoring, signalling, control at power facilities; digital substations; other systems requiring high-precision universal time reference. The devices of the universal time system assure two variants of transmission of standard time signals:

  • via communication links based on “twisted pair” or optical fiber;
  • via an Ethernet network according to the standard IEEE 1588-2008 (PTPv2).


The devices of the universal time system:

  • an SKhr-2 synchronometer;
  • URSM-1, URSM-2, URSM-3 main signal amplifiers-retransmitters;
  • an USKhr-2 synchronizing device (can contain SKhr-2, URSM-1, URSM-2, URSM-3).

Functions of SKhr-2:

  • receiving time synchronization signals from:
  • satellite navigation systems (SNS);
  • an NTP server (RFC 1305) via an Ethernet network;
  • two independent synchronized time sources;
  • shaping and delivering standard time signals via communication links based on optical fiber;
  • delivering second mark signals (1PPS) in the form of a TTL-compatible pulse;
  • delivering messages via a 100Base-FX optical interface for time synchronization in an Ethernet network;
  • time keeping in an autonomous mode (when there are no external sources of synchronization);
  • displaying time, date, diagnostic information, as well as possibility to configure with the help of a touch screen;
  • monitoring operability with generation of diagnostic messages into an Ethernet network;
  • possibility to connect both single and redundant power supply.

Functions of USKhr-2:

  • multiplying output signals of SKhr-2 with transmission via a fiber-optical communication link;
  • converting optical signals into electric ones with transmission via “twisted pair” in accordance with the Ch7-43 synchronometer protocol;
  • assuring connection of the main optical cable via an optical cross;
  • providing uninterruptible power supply for SKhr-2 and auxiliary equipment (direct current with voltage 27±0.8 V with operation from a network and from 19 to 28 V with operation from a backup accumulator battery);
  • monitoring operability and diagnosing component parts.

Functions of URSM-1, URSM-2, URSM-3 – amplifying and multiplying signals to build a branched universal time network, converting optical signals into electric ones with transmission via “twisted pair” in accordance with the Ch7-43 synchronometer protocol and backwards.
URSM-1 has:

  • one input (optical or “twisted pair”);
  • one optical output;
  • two “twisted pair” outputs for mainline connection of up to 25 abonents.

URSM-2 has:

  • one input (optical or “twisted pair”);
  • six optical outputs
  • one “twisted pair” output for mainline connection of up to 25 abonents.

URSM-3 has:

  • four inputs (two optical ones and two “twisted pair” ones);
  • two optical outputs;
  • six “twisted pair” outputs for mainline connection of up to 75 abonents;
  • automatic disconnection of synchronization from a faulty source;
  • automatic time keeping when there is no connection with all sources.

One of arrangement variants for the universal time system based on USKhr-2, SKhr-2, URSM-1, URSM-2, URSM-3 is given in the figure.

 

Fig. 1. – One of versions of the universal time system

 

TECHNICAL CHARACTERISTICS OF THE DEVICES
Characteristic Value
Metrological characteristics of SKhr-2
1 Error of standard time signal shaping as related to UTC during synchronization from SNS, ms, not more than ±1
2 Accuracy of seconf mark signal delivery (1PPS), µs ±1 per 1000 periods
3 Error of event affixing to the universal time of the system, ms, not worse than ±2
Characteristics of communication links
4 Distance of a receiving antenna from SKhr-2, m up to 100
5 Types of communication links based on “twisted pair” or optical fiber
6 Length of communication links between amplifiers-retransmitters, m:
  • “twisted pair”
  • optical fiber

  • up to 100 (pseudomainline)
    up to 1000 (radially)
7 Quantity of ports of SKhr-2:
  • optical Ethernet
  • optical fiber

  • 2
    4 (2 inputs and 2 outputs)
8 Type of connectors:
  • “twisted pair”
  • optical fiber
  • optical Ethernet

  • RJ-45
    SC
    MTRJ
Characteristics of power supply of SKhr-2
9 Operating voltage (direct current), V from 19 to 35
10 Power consumption, W, not more than 15
11 Power supply channels 2
Characteristics of design
12 Overall dimensions, mm:
  • SKhr-2
  • USKhr-2

  • 205 x 145 x 130
    750 x 610 x 900
13 Weight, kg, not more than:
  • SKhr-2
  • USKhr-2

  • 3,5
    100
Conditions of operation
14 Ambient air temperature, °C from +15 to + 50
15 Relative air humidity, % from 10 to 75
16 Atmospheric pressure, kPa from 86 to 108

SRPA “Impulse” is a leading Ukrainian designer, manufacturer, and supplier of highly-reliable instrumentation and control systems for nuclear power engineering and railways.
 
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