CN201557118U

CN201557118U - GPS dipper dual-mode precision network clock

Info

Publication number: CN201557118U
Application number: CN2009202117052U
Authority: CN
Inventors: 张强; 邱祖雄; 苏金广
Original assignee: Shanghai Taitan Communication Engineering Coltd
Current assignee: NS communication technology (Shanghai) Co., Ltd.; Shanghai Taitan Communication Engineering Co.Ltd
Priority date: 2009-11-02
Filing date: 2009-11-02
Publication date: 2010-08-18
Anticipated expiration: 2019-11-02

Abstract

The utility model relates to a GPS dipper dual-mode precision network clock, comprising a GPS/dipper dual-mode receiving machine. The GPS dipper dual-mode precision network clock is characterized in that the GPS/dipper dual-mode receiving machine is connected with an FPGA unit that is connected with a synthesizer, an oscillator and a second pulse generator respectively. The GPS dipper dual-mode precision network clock has the following advantages: the GPS/dipper dual-mode redundant input of one clock is realized, the reliability of the system is improved; the traditional time signals, such as pulse, can be output, furthermore, the output of the high-precision network time is realized mainly; the FPGA contains a large amount of software arithmetic so as to process various state/control information output by the GPS/dipper receiving machine; and the SNMP alarm and dry contact alarm are supported.

Description

GPS Big Dipper bimodulus precision net clock

Technical field

The utility model relates to a kind of GPS Big Dipper bimodulus precision net clock, this clock can be realized obtaining standard time UTC from GPS and big-dipper satellite system, not only exportable traditional pulse equal time sign indicating number, can also export state-of-the-art in the world at present network to the time signal PTP (Precision Time Protocol, be IEEE 1588), belong to communication technical field.

Background technology

Along with developing rapidly of electronic communication, many industries are more and more higher to the requirement of time precision.Particularly in fields such as communication, electric power, traffic, finance, the precise time signal is the necessary guarantee of the normal operation of various automation equipments, and the time deviation of millisecond even microsecond level all might cause system works unusual, causes the loss that can't retrieve.

Be synchro system settling time at the general solution of this problem at present.Promptly obtain absolute time UTC, again this system time is applied to each system, make that the equipment of free mark demand all uses reference frame at the same time in this system by GPS or other satellite system, thus the unanimity of realization various kinds of equipment time.

Current application is the most ripe be gps satellite to the time technology.GPS is the GPS (Global Position System) of the U.S., is made up of 24 gps satellite and ground control stations at space motion.Anywhere, any time gps satellite signal receiver all can be received sufficient amount (at least four s') gps satellite signal at the earth's surface.Although gps system is quite ripe, it is subjected to the control of US military after all, and the U.S. also never does with regard to the reliability of this system to any country and appears promise.Simultaneously, U.S. official announces constantly that also the problem of paralysing may soon appear in gps system owing to reasons such as lifetime of system in recent years.Given this, adopt GPS/ Big Dipper bimodulus to receive necessary.

The signal type of time synchronized comprise pulse by common cable transmission, IRIG-B, serial ports message and based on the network of TCP/IP transmitted in both directions to the time agreement NTP and PTP etc.Pulse, IRIG-B and serial ports message to the time mode be widely used in communicating by letter, a lot of fields such as electric power, be very ripe to the time technology.NTP also has been widely used in many fields, and its outstanding advantage is that it can arbitrarily realize time synchronized in the IP network, its inferior position then show its to the time precision have only Millisecond.And PTP not only has the two-way time delay of the NTP ability of compensation automatically, the more important thing is that its precision is a nanosecond.And nanosecond to the time precision can satisfy nearly all field to the time requirement.

PTP (Precision Time Protocol) agreement is also referred to as IEEE 1588, and this standard is a precision interval clock synchronous protocol standard of being devoted to industry control and measurement at the beginning of proposing, and target provides the synchronization accuracy of submicrosecond and uses.This standard had received the concern of the especially distributed motion control field of automatic field afterwards, and started to walk in application of military field in the world, and linked groups such as telecommunication and electric power system also show keen interest to it.

It should be noted that more the PTP agreement is a kind of procotol based on TCP/IP, the beyond challenge flexibility of data network has made it become the topmost communication mode in each field.Traditional pulse, IRIG-B etc. firmly to the time mode can only be confined to the time synchronized in very little field, and manageability not, it will by based on the PTP of data network transmission to the time mode replace.Particularly along with the arrival of 3G communication, the PTP The Application of Technology will be developed on an unprecedented scale.

Summary of the invention

It is the clock of time reference with GPS/ Big Dipper dual-satellite system that the purpose of this utility model provides a kind of, except that can exporting traditional pulse equal time signal, can also export state-of-the-art in the world at present network to the time signal PTP.

In order to achieve the above object, product technology scheme of the present utility model has provided a kind of GPS Big Dipper bimodulus precision net clock, comprise GPS/ Big Dipper dual mode receiver, it is characterized in that, GPS/ Big Dipper dual mode receiver connects the FPGA unit, and the FPGA unit connects synthesizer, oscillator and second pulse generator respectively.

Further, described FPGA unit connects the PTP protocol stack module, and the PTP agreement connects ICP/IP protocol stack module, and ICP/IP protocol stack module connects the MAC unit, and the MAC unit connects the PHY unit, and the markers engine connects PTP protocol stack module and PHY unit respectively.

Described FPGA includes a large amount of software algorithms, to handling from the various message and the time of GPS/ Big Dipper dual mode receiver.The information that GPS/ Big Dipper dual mode receiver is provided wants complicated more than simple GPS receiver or Big Dipper receiver, relates to the switching of different system satellite and the judgement of operating state etc.And time signal is shaken filtering, further improve time precision.FPGA handles PTP information simultaneously.

The utility model adopts the hierarchy design, as PHY unit, MAC unit, ICP/IP protocol stack module, PTP (1588v2) protocol stack module etc., has fully guaranteed the high-precision requirement of PTP time.

Advantage of the present utility model is:

1. realize a clock GPS/ Big Dipper duplication redundancy input, improved the reliability of system;

2. except that exportable traditional time signal such as pulse, mainly realized the output of high-accuracy network time;

3.FPGA comprising various state/control informations that a large amount of software algorithms exported GPS/ Big Dipper receiver handles;

4. support SNMP alarm, dry contact alarm.

Description of drawings

The connection diagram of a kind of GPS Big Dipper bimodulus precision net clock that Fig. 1 provides for the utility model.

Embodiment

Specify the utility model below in conjunction with embodiment.

Embodiment

As shown in Figure 1, a kind of GPS Big Dipper bimodulus precision net clock that provides for the utility model, comprise GPS/ Big Dipper dual mode receiver, product technology scheme of the present utility model has provided a kind of GPS/ Big Dipper bimodulus input PTP time synchronized networking clock, comprise GPS/ Big Dipper dual mode receiver, GPS/ Big Dipper dual mode receiver connects the FPGA unit, and the FPGA unit connects synthesizer, oscillator and second pulse generator.

Processing for the PTP time is finished by the FPGA unit, for guaranteeing its precision, has adopted the thought of hierarchical design.Described FPGA unit connects PTP (1588v2) protocol stack module, and PTP (1588v2) agreement connects ICP/IP protocol stack module, and ICP/IP protocol stack module connects the MAC unit, and the MAC unit connects the PHY unit.The markers engine connects PTP (1588v2) protocol stack module and PHY unit.

PTP (Precision Time Protocol, IEEE 1588): i.e. chronometer time agreement.IEEE1588 has defined one in measurement and Control Network, with internet exchange, the local agreement (PTP, Precision Time Protocol) of calculating the precise synchronization clock relevant with distributing object.This agreement is not exclusive, and it is particularly suitable for the technology based on Ethernet, and precision can reach nanosecond.The mechanism of the next synchronous local zone time of its seal service time.Even synchronous control signal produces certain fluctuation when network service, by adopting the corresponding software algorithm, the precision that it reached still can meet the demands, and this makes it be particularly useful for system based on Ethernet.PTP has inherited the low cost pattern of NTP based on Ethernet, provide again simultaneously be better than IRIG-B to the time accuracy, and PTP can transmit in general network, too many time delay and shake can not exert an influence.Experiment shows that this technology precision time calibration can reach 1 μ s at present behind the time receiving system of selecting high-quality, can also further improve from now on.

Wherein the FPGA unit pack contains related software and the algorithm that is useful on the PTP processing.

Claims

1. a GPS Big Dipper bimodulus precision net clock comprises GPS/ Big Dipper dual mode receiver, it is characterized in that, GPS/ Big Dipper dual mode receiver connects the FPGA unit, and the FPGA unit connects synthesizer, oscillator and second pulse generator respectively.

2. a kind of GPS Big Dipper bimodulus precision net clock as claimed in claim 1, it is characterized in that, described FPGA unit connects the PTP protocol stack module, the PTP agreement connects ICP/IP protocol stack module, ICP/IP protocol stack module connects the MAC unit, the MAC unit connects the PHY unit, and the markers engine connects PTP protocol stack module and PHY unit respectively.