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