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).
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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
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- up to 100 (pseudomainline)
up to 1000 (radially)
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7 |
Quantity of ports of SKhr-2:
- optical Ethernet
- optical fiber
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- 2
4 (2 inputs and 2 outputs)
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8 |
Type of connectors:
- “twisted pair”
- optical fiber
- optical Ethernet
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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:
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- 205 x 145 x 130
750 x 610 x 900
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13 |
Weight, kg, not more than:
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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 |