CN201557117U

CN201557117U - GPS and nanosecond NTP two-way inputted synchronous networking clock

Info

Publication number: CN201557117U
Application number: CN2009202117033U
Authority: CN
Inventors: 朱亚; 邱祖雄; 李凤军
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 and nanosecond NTP two-way inputted synchronous networking clock which comprises a FPGA processor, wherein the FPGA processor is respectively connected to a host machine processing interface, a memorizer and a bus. A GPS receiving unit, a package filtering unit, a clock synchronous unit and a bus host machine are hung on the bus. The package filtering unit is connected to a MAC controller; the clock synchronous unit is respectively connected to an input/output module, a constant temperature control DAC and bus host machine; and the bus host machine is connected with an oscillator. The utility model has the advantages that the GPS and nanosecond NTP two-way redundant input promotes the reliability of the system, the time output is provided while a frequency signal accorded with the ITU-T G. 811 standard is outputted, the FPGA control has a powerful function of the operation panel and the equipment can be remotely managed and monitored through web.

Description

The synchronous network clock of a kind of GPS and the input of nanosecond NTP two-way

Technical field

The utility model relates to the synchronous network clock of a kind of GPS and the input of nanosecond NTP two-way, can obtain the UTC time by following the tracks of the gps satellite system, and is perhaps synchronous with upstream clock by the NTP input.It is the NTP time of exportable nanosecond not only, can also export simultaneously to meet the G.811 frequency signal of standard of ITU-T, can be used as the frequency reference of communication network, belongs to communication technical field.

Background technology

Progress along with development of science and technology and society, many industries are more and more higher to the requirement of time precision, high-precision system time is the prerequisite of numerous areas safe and reliable operation synchronously, as electric power, traffic, communication, financial instrument, radio and television, national defense and military, space flight scientific research etc.

At present the most frequently used time dissemination system is the gps satellite navigation system regularly of US military exploitation, time synchronized in can being divided among a small circle to the application of split-second precision signal from locking range and time synchronized on a large scale.

Time synchronized among a small circle promptly this among a small circle in for each equipment provides a cover gps system, more reliable mode be by a cover gps system for all devices in this scope by cable directly carry out to the time.Nei time synchronized is more extensive from the region on a large scale, as the whole network system of a province; On the basis of each inter-sync system among a small circle,, guarantee the time synchronized between all systems by transmission network synchronizing network settling time.

Present existing GPS synchronised clock brand is more, the system's time service in can both satisfying substantially among a small circle, but it is considerably less to be used for setting up the GPS network clocking of time synchronization network.

Summary of the invention

The purpose of this utility model provides a kind of GPS network clocking that can be used for setting up time synchronization network, can play simultaneously among a small circle in system's master clock, network master clock, network from the effect of clock, its networking precision reaches nanosecond.

In order to achieve the above object, product technology scheme of the present utility model has provided the synchronous network clock of a kind of GPS and the input of nanosecond NTP two-way, comprise the FPGA processor, it is characterized in that, the FPGA processor connects host process interface, memory and bus respectively, on bus, hang with GPS receiving element, packet filtering unit, clock synchronization unit and bus host, the packet filtering unit connects mac controller, the clock synchronization unit connects input/output module, thermostatic control DAC and bus host respectively, the bus host connection oscillator.

Further, described bus is I ²The C bus.Described oscillator is a time holding unit OCXO oscillator.

The input of the two-way of the clock that the utility model provides can be set priority, and PTP not only can be used as input, also can be used as output and uses.

Advantage of the present utility model is:

1. realize a clock GPS, the redundant input of nanosecond NTP two-way, improved the reliability of system;

2. except that time output can be provided, can also export simultaneously and meet the G.811 frequency signal of standard of ITU-T;

3. during networking, a large amount of software algorithms has overcome the accuracy error that is caused by the Network Transmission shake;

4.FPGA control, guidance panel is powerful, can carry out telemanagement and monitoring to equipment by Web;

5. unique nanosecond data network networking precision particularly also can reach the precision that is better than 1 microsecond by router;

6. support SNMP alarm, dry contact alarm etc.

Description of drawings

The connection diagram of the synchronous network clock of a kind of GPS that Fig. 1 provides for the utility model and the input of nanosecond NTP two-way;

Embodiment

Specify the utility model below in conjunction with embodiment.

Embodiment

As shown in Figure 1, the synchronous network clock of a kind of GPS that provides for the utility model and the input of nanosecond NTP two-way, comprise the FPGA processor, it is characterized in that, the FPGA processor connects host process interface, memory and bus respectively, on bus, hang with GPS receiving element, packet filtering unit, clock synchronization unit and bus host, the packet filtering unit connects mac controller, the clock synchronization unit connects input/output module, thermostatic control DAC and bus host respectively, the bus host connection oscillator.Described bus is I ²The C bus.Described oscillator is a time holding unit OCXO oscillator.

When this clock during, obtain the UTC time by the GPS receiver, as fiducial reference source as system's master clock.The signal of GPS receiver output communicates with other circuit by the mode and the FPGA processor of bus.

NTP:Network Time Protocol, i.e. NTP (Network Time Protocol).NTP (Network Time Protocol) (NTP) be a kind of by Internet service in the agreement lock in time of computer clock.It provide a kind of lock in time mechanism, can in huge and complicated various internet, distribute with the whole time of light velocity modulation.But what it used is the return time design, and be characterized in: time server is a kind of distributed subnet, and the operation of energy self, multi-zone supervision configuration meet international standards the time through wired or wireless mode synchronous logic clock.In addition, by local Route Selection algorithm and time background program, server can be redistributed the standard time.

The design of NTP has brought three kinds of product-clock skews, time delay and residual quantity, and all these three kinds all are associated with the designated reference clock.Clock skew represents to adjust local clock and the variation that produce consistent with reference clock; Time delay is illustrated in the delay time that sends in the fixed time between message and reference clock; Residual quantity has been represented the maximum deviation mistake with respect to the reference clock local clock.Because most of main frame time servers reach synchronous by other reciprocity time server, so each in these three kinds of products all has two parts: the first is by the part of equity decision, and this part is for the reference source of primary standard time; It two is parts of being weighed by main frame, and this part is for equity.Each part is all independently kept in agreement, thereby can make the bookkeeping of wrong control and subnet itself become easy.The accurate measurement that they not only provide skew and have postponed, and clear and definite maximum error range is provided, user interface not only can determine the time like this, and can determine the accuracy of time.

Input module is a kind of module that is used for the time of reception signal, can receive the NTP time signal by network, and with the NTP decoding, thereby output serial ports time message signals and 1PPS signal.Traditional NTP beats markers in application layer, the time precision that this technology can reach has only the hundreds of microsecond, and nanosecond NTP network clocking is beaten markers by driving at Ethernet, precision depends on the interruption reaction time of interrupt service routine of Ethernet and the transmission hardware of Ethernet, and precision can reach the ns level.

Also be to control by the mode of bus between the output unit of equipment and the core processor, the output unit of nanosecond NTP networking clock can be exported various types of time signals, as IRIG-B, 1PPS, TOD etc.As a gps time product, it can also meet the G.811 E1 frequency signal of level of ITU-T by output accuracy simultaneously, and this is the present not available function of other any a clock.

Claims

1. the synchronous network clock of GPS and nanosecond NTP two-way input, comprise the FPGA processor, it is characterized in that, the FPGA processor connects host process interface, memory and bus respectively, on bus, hang with GPS receiving element, packet filtering unit, clock synchronization unit and bus host, the packet filtering unit connects mac controller, and the clock synchronization unit connects input/output module, thermostatic control DAC and bus host respectively, the bus host connection oscillator.

2. the synchronous network clock of a kind of GPS as claimed in claim 1 and the input of nanosecond NTP two-way is characterized in that described bus is I ²The C bus.

3. the synchronous network clock of a kind of GPS as claimed in claim 1 and the input of nanosecond NTP two-way is characterized in that described oscillator is a time holding unit OCXO oscillator.