Four-port backup device for coupling of circular networks of communication network

FIELD: radio engineering, communications.

SUBSTANCE: four-port backup device (FPBD), comprises two switchboards (2) of data packets, every of which is connected to the other switchboard (2) and with two ports (3 and 4), designed for connection into the first and second circular communications networks, and a clock synchronisation unit (5). To the unit (5) the outlets of two receivers (6) and (7) are connected, as well as inlets of two transmitters (8) and (9), designed for the first circular network, outlets of two receivers (10 and 11), inlets of two transmitters (12 and 13), designed for the second circular network, and the outlet of the receiver (14) of the external synchronisation signal. The unit (5) is made as capable of generation of a clock signal synchronised with output signals of receivers with introduction of a fixed delay of an output signal for each receiver, issue of a generated signal to inlets of transmitters, and as capable of translation of output signals of receivers to inlets of transmitters designed for the identical network. The device is equipped with a configuration interface (15) as capable of setting the receivers and transmitters of the synchronising signal, delay values of output signals of receivers and permit or prohibition of transmission of output signals of receivers to inlets of transmitters.

EFFECT: improved accuracy of clock synchronisation.

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The technical FIELD

The invention relates to the field of construction of communication data networks with ring redundancy and can be used in automation systems, energy facilities, built according to international standard IEC61850 [IEC 61850-5 "Systems and communication networks in substations. Part 5. Communication requirements for functions and equivalent circuits (electronic) devices". 2003 (Electronic resource). Access mode http://www.standards.ru/document/3643715.aspx] with high requirements for precision timing.

In particular, the proposed four-port device can be used for coupling a pair of ring networks in a shared communication network Protocol (HSR international standard IEC 62439-3 [IEC 62439-3 "Industrial communication network. Network with high willingness to automatic processing. Part 3. The Protocol parallel redundancy (PRP) and seamless redundancy with high availability (HSR)". 2010 (Electronic resource). Mode of access: http://www.standards.ru/document/4561443.aspx].

The LEVEL of TECHNOLOGY

In IEC 62439-3 described device QuadBox, which is a four-port device for coupling two ring networks into a single communication network with a ring redundant data.

Synchronize data in the internetwork, use the known device is the primary objective, made through the use of specific regulations of the packet data, which does not allow for increased demands on the accuracy of the synchronization imposed by the standard IEC61850 (for example, in accordance with the classes of T4 or T5 specified standard, the timing accuracy must be within ±4 μs or ±1 µs, respectively).

DISCLOSURE of INVENTIONS

The technical result of the invention is to improve the accuracy of clock synchronization in data transmission in a communication network with redundant formed by coupling at least two ring networks. In the case of use of the invention in the automation system of a plant constructed in accordance with the standard IEC 61850, ensures precise synchronization in accordance with the class T5.

The above technical result is achieved due to the fact that in four-port device reservation (hereinafter referred to MIND), containing two interconnected switch data packets, each of which is associated with two data ports, and block clock synchronization, added four receivers, four of the transmitter clock and the receiver of the external synchronization signal, the outputs of the receivers and the inputs of the transmitters connected to the block clock synchronization, which is made with the possibility of what enerali clock signal, synchronized outputs of the receivers with the introduction of a fixed delay for each of the receivers, the issuance of the generated signal to the inputs of the transmitters, and streaming output signals, at least two receivers of the clock signals at the inputs of the respective transmitters, the device is equipped with the interface configuration with the ability to set the modes of the receivers and transmitters of the clock signals, values of the delay signals of the receivers and enable or disable broadcast clock signals.

BRIEF DESCRIPTION of DRAWINGS

Figure 1 shows the proposed scheme CHUR.

Figure 2 shows an exemplary diagram of a communication network with two ring networks, related offer CHUR.

The IMPLEMENTATION of the INVENTION

CHUR 1 contains (see figure 1):

two switch 2 data packets, which are interconnected;

two communication port 3 connected to switch 2 and intended for the first ring network;

two communication port 4 connected to another switch 2 and destined for the second ring network;

unit 5 clock synchronization;

the first 6 and second 7 receivers clock signals intended for the first ring network;

- the first 8 and second 9 transmitters clock signals intended DL the first ring network;

the first 10 and second 11 receivers clock signals intended for the second ring network;

the first 12 and second 13 transmitters clock signals intended for the second ring network;

receiver 14 external synchronization;

interface 15 configuration.

Part CHUR 1, includes a pair of communication ports 3, a pair of communication ports 4 and two interconnected switch 2 data packets, operates similarly to the device QuadBox"described in the standard IEC 62439-3. Work the rest of CHUR, which includes the block 5, the receivers 6, 7, 10, 11 and 14, the transmitter 8, 9, 12 and 13, described below.

The receivers 6, 7, 10, 11 and 14 carry out reception of signals of clock synchronization from an external communication channels and broadcast the received signals to the block 5. Transmitters 8, 9, 12 and 13 transmit obtained from block 5 signal clock synchronization in the corresponding ring network. At the same time as the receivers 6, 7, 10, 11 and 14, and the transmitter 8, 9, 12 and 13 provide almost deterministic operation broadcast clock signal with the magnitude of the uncertainty of the time of operation is not more than ±0,01 ISS.

The operation unit 5 clock synchronization depends on the selected mode of operation CHUR, which allows operation in one of two modes: mode source and relay signals so the new synchronization.

When working CHUR mode source clock synchronization unit 5 in the structure of the device 1 performs the following functions:

- accepts external signal receiver 14 and introduces a fixed delay of the output signal for the receiver.

- generates a clock signal synchronized detainees output signal of the receiver 14;

- outputs the generated signal to the transmitter 8, 9, 12 and 13.

This ensures the continuous formation of an internal timeline, its correction by synchronizing the delayed signal of the receiver 14, the formation and transmission of the output signal of clock synchronization on the transmitters 8, 9, 12 and 13.

The introduction of fixed delay compensates delivery time of a clock signal from an external clock source via a communication channel to the device TOO. The value of this delay can range from zero to several microseconds and must be in increments of not greater than 0.25 μs.

When working CHUR mode repeater clock synchronization operation unit 5 clock synchronization depends on the location of the source of clock synchronization, which can be located in both the first and the second ring communication network to which the device CHUR connected.

When the clock source is the synchronization in the first ring communication network unit 5 receives the clock signals from the receivers 6 and 7, when the clock source to synchronize the second ring communication network, respectively, of the receivers 10 and 11.

When the clock source synchronization in the first ring communication network clock signal received from the receiver 6 is transmitted to the transmitter 9 and the clock signal received from the receiver 7, a transmitter 8. When the clock source to synchronize the second ring communication network is broadcasting the clock signal received from the receiver 10, the transmitter 13, and the signal received from the receiver 11, a transmitter 12.

When the above broadcasts a clock signal unit 5 provides almost deterministic execution time of individual operations broadcast clock signal with the magnitude of uncertainty run-time operations broadcast from the receiver to the corresponding transmitter is not more than ±0.1 microsecond).

When working CHUR in extender mode, the unit 5 performs the following functions:

- introduces a fixed delay for the output signal to the receivers 6 and 7 or receivers 10 and 11;

- generates a clock signal synchronized detainees output signals of the respective receivers;

- outputs the generated signal to the respective transmitters.

This provides continuously the formation of the internal time scale, its correction due to the synchronization of the delayed signals of the receivers 6 and 7 or receivers 10 and 11, the formation and transmission of the output signal of clock synchronization on the transmitters 12 and 13 or transmitters 8 and 9 depending on which ring network is a source of clock synchronization.

The introduction of fixed-delay signal receivers, and in this mode compensates delivery time of a clock signal from an external clock source via a communication channel to the device CHUR.

The interface 15 configuration provides connectivity to CHUR external workstation to perform configuration of devices, in particular, the settings of the operation unit 5 clock sync. When performing configuration CHUR via the interface 15 is provided:

- set the mode of functioning of the CHUR - source mode or repeater mode signals, clock synchronization, and also in the case of the mode selector relay sets the location of the source clock synchronization (in the first or second ring communication network);

- assignment of values to the fixed delay of the output signals for each of the receivers 6, 7, 10, 11 and 14.

In the case of an assignment operation CHUR mode source as the receiver clock signal is set on the in the receiver 14, prohibited the transmission of signals between all pairs of receivers and transmitters connected to the first and second ring communication network (pair receiver - transmitter 6-9, 7-8, 10-13, 11-12).

In the case of an assignment operation CHUR in extender mode, and specify the location of the source of clock synchronization in the first ring communication network as the receiver clock signals are the receivers 6 and 7, set the resolution of the broadcast clock signals between pairs of receivers and transmitters 6-9 7-8 and ban broadcast between pairs of receivers and transmitters and 11-12 10-13. In the case of an assignment operation CHUR in extender mode, and specify the location of the source of clock synchronization in the second ring communication network as the receiver clock signals are receivers 10 and 11, set the resolution of the broadcast clock signals between pairs of receivers and transmitters and 11-12 10-13 and ban broadcast between pairs of receivers and transmitters 6-9 7-8;

The receivers 6, 7, 10, 11 and 14 and the transmitter 8, 9, 12 and 13 in the device CHUR can be implemented on the basis of standard optical receivers and transmitters, for example, HFBR-24×6Z and HFBR-1712TZ from the manufacturer Avago Technologies. Unit 5 clock synchronization can be performed on the basis of the programme is Miramas logical integrated circuit (FPGA) and highly stable crystal oscillator. The interface 15 of the configuration can be made on the basis of the standard Ethernet interface (IEEE 802.3).

Figure 2 shows an example of constructing a communication network using the proposed device. The communications network shown in figure 2, comprises two annular communication network connected via CHUR. Figure 2 shows:

external source 16 signals of clock synchronization;

single - wire segments 17 and 18 to transmit data in the first and second ring network, respectively;

- two wire segments 19 and 20 for the bidirectional transmission of the clock signals in the first and second ring network, respectively;

- Quad-port device 1 redundancy, connected to the segments 17, 19 of the first ring network and to the segments 18 and 20 of the second ring network and, thus, included in each ring network as its host;

- intelligent electronic device 21 that supports the inclusion in the ring communication network directly (without using an intermediate device redundancy);

- intelligent electronic device 22 that do not support the inclusion in the ring communication network and connected to the rings 17 and 18 through nodes 23.

The network presented in figure 2, in terms of data transfer functions in accordance with IEC 62439-3, and in part II of the passing of signals of clock synchronization - as follows.

The alarm clock comes in the first ring network (segment 19) from an external source 16 (which may be, for example, the system software universal time power facility) through one of the nodes 23, which functions in the source mode, generating and sending a clock signal synchronized with other devices of the first ring network, the associated segments 19, as well as intelligent electronic device 22 included in the first ring network through the node 23. Other nodes 23 in the first ring network when receiving the signal timings from the neighboring node 23 relay this signal to another adjacent node 23, providing, thus, a bidirectional signal transmission clock synchronization segment 19.

CHUR 1 relays the signals of clock synchronization from the first ring network connected to the source 16 of the clock signals in the second network, the nodes of which are connected by segments 20. In the internetwork is provided a ring redundancy as data transmission, and signal timings.

The segments 19 and 20 for the bidirectional transmission of signals of clock synchronization can be implemented, for example, on the basis of fiber-optical networks transmit signals 1PPS (one-pulse-per-second"). In the case of the especiany execution nodes 22 and CHUR compensation delivery time of the clock signal from the signal source to the receiver increments the value of the temporal compensation is not greater than 0.25 μs and with the above valid magnitudes of uncertainties delays provided by the nodes 22 and CHUR with the broadcast clock signals (±0.01 µs - uncertainty of the delay introduced by the receiver or transmitter, ±0.1 microsecond - the uncertainty of the delay introduced by the block clock synchronization of the device with the broadcast from the receiver to the transmitter) precision clock synchronization devices in the communication network at least ±1 µs.

The four-port device backup, containing two interconnected switch data packets, each of which is associated with two data ports, and block clock synchronization, characterized in that the device entered four receivers, four of the transmitter clock signal and the external signal receiver synchronization, outputs, receiver inputs and transmitter clock signals connected to the block clock synchronization, which is configured to generate a clock signal synchronized output signals of the receivers with the introduction of a fixed signal delay of each of the receivers, the issuance of the generated clock signal to the inputs of the transmitters and streaming clock signal outputs, at least two receivers of the clock signals at the inputs of the respective transmitters, the device is equipped with an interface konfigurirovanie is capable modes of receivers and transmitters clock signals, values of the delay signals of the receivers and enable or disable broadcast of the clock signals.