CN201557123U

CN201557123U - Device for converting network time signal into direct current time code

Info

Publication number: CN201557123U
Application number: CN200920211700XU
Authority: CN
Inventors: 苏金广; 邱祖雄; 王以诚
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 device used for converting a network time signal into a direct current time code, which comprises a controlling unit; and the device is characterized in that the controlling unit is respectively connected with a physical layer transceiver, an MAC controller, a microcontroller, an oscillator, a filter, a drive circuit I, a drive circuit II and an LED indicator lamp, wherein the physical layer transceiver is connected with an RJ45 interface, the MAC controller and the microcontroller are connected with an microcontroller module respectively through a USB line concentrator, and the microcontroller is connected with an FPGA configuration controller and also connected with the oscillator through an analog-digital conversion circuit. The utility model has the advantages that the processing to the PTP timing mark is realized through the FPGA chip, and the accurate extraction of the PTP time input can be ensured without a complex circuit; the PTP port can be taken as the management port of the device at the same time; the appearance and the port of the device can be customized according to the requirements of the timed device; and the time-delay compensation of the cable can be automatically calculated, the precision is high, and the application is convenient.

Description

A kind of network time signal commentaries on classics direct current timing code device

Technical field

The utility model relates to a kind of network time signal commentaries on classics direct current timing code device, is used for precision net time signal PTP (Precision Time Protocol) is converted into the DCLS time signal, belongs 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.Current locus, accurate Calculation receiver place and time, the relative UTC time error of its time precision can reach nanosecond.Gps clock is a point-device time source, most Time Synchronization Network all it as reference time source.

The signal type of time synchronized comprise pulse by common cable transmission, IRIG-B (wherein the IRIG-B of direct current is called DCLS), 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 was subjected in 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.Along with developing rapidly of PTP setting network, a large amount of traditional based on DCLS to the time equipment to insert the PTP network, just must at first finish the conversion of PTP to DCLS.But what do not have a kind of maturation so far finishes the device of PTP to DCLS conversion.

Summary of the invention

The purpose of this utility model provides the equipment of a kind of PTP of realization time signal to traditional DCLS conversion of signals.

In order to achieve the above object, product technology scheme of the present utility model has provided a kind of network time signal commentaries on classics direct current timing code device, comprise control unit, it is characterized in that, control unit connects physical layer transceiver respectively, mac controller, microcontroller, oscillator, filter and drive circuit, drive circuit and LED light, physical layer transceiver connects the RJ45 interface, mac controller and microcontroller connect external microprocessor module by usb hub respectively, and microcontroller connects the FPGA Configuration Control Unit, and by mould/number conversion circuit connection oscillator.

Further, described control unit is FPGA.

The utility model is handled the PTP network time that receives by fpga chip.FPGA is extensive programmable logic chip, have characteristics such as logical block is flexible, integrated level height, can directly handle the PTP signal, and need not to adopt complicated circuit that the PTP signal is transformed, thereby can guarantee from the PTP message that receives, to recover precise time.The built-in crystal oscillator of the utility model carries out " training " by FPGA control to it, and FPGA receives the frequency output of this crystal oscillator simultaneously, and further exports the high accuracy clock signal and give drive circuit, physical layer transceiver, mac controller etc.

The utility model has the advantages that:

Target is handled when (1) realizing PTP by fpga chip, and need not to adopt complicated circuit, can guarantee the accurate extraction that the PTP time is imported;

(2) the PTP port can be used as the management mouth of this device simultaneously;

(3) equipment profile and interface can according to by to the time equipment requirement customize;

(4) calculate the cable delay compensation automatically, the precision height, it is convenient to use.

Description of drawings

The connection diagram that a kind of network time signal that Fig. 1 provides for the utility model changes direct current timing code device.

Embodiment

Specify the utility model below in conjunction with embodiment.

Embodiment

As shown in Figure 1, a kind of network time signal that provides for the utility model changes direct current timing code device, comprise control unit, control unit adopts FPGA in the present embodiment, FPGA connects physical layer transceiver, mac controller, microcontroller, oscillator, filter and drive circuit, drive circuit and LED light respectively, physical layer transceiver connects the RJ45 interface, mac controller and microcontroller connect external microprocessor module by usb hub respectively, and microcontroller connects the FPGA Configuration Control Unit, and by mould/number conversion circuit connection oscillator.

The network that PTP is based on ICP/IP protocol to the time agreement, this equipment adopts general RJ45 interface.PTP and traditional difference of NTP (Network Time Protocol) are that PTP beats markers in physical layer, and precision is far above target NTP technology when application layer is beaten, the nanosecond that the PTP precision reaches.Physical layer transceiver carries out markers to the PTP message that receives and extracts, and the time scale information that is obtained is sent to FPGA, is handled by FPGA.Because also can beating markers to the temporal information of FPGA output simultaneously, a kind of bidirectional protocol during PTP, physical layer transceiver in the PTP agreement, transmit.

The RJ45 mouth can also carry out the transmission of network management information simultaneously except that carrying out the transmission of PTP.

FPGA (Field-Programmable Gate Array), i.e. field programmable gate array.FPGA has adopted the such new ideas of logical cell array LCA (Logic Cell Array), and inside comprises configurable logic blocks CLB (Configurable Logic Block), output input module IOB (Input OutputBlock) and three parts of interconnector (Interconnect).There are abundant trigger and I/O pin in FPGA inside, and FPGA adopts high speed CHMOS technology, and is low in energy consumption, can with CMOS, Transistor-Transistor Logic level compatibility.Time for high accuracy nanosecond handles, and the fast advantage of FPGA processing speed has obtained putting to good use fully.Fireballing advantage derives from the hard logic mode of FPGA.Because the logic function of FPGA realizes with hardware circuit that all so all delays only derive from gate circuit, and the delay of general gate circuit is all in the ns rank.

FPGA contains a large amount of software algorithms, can eliminate the shake that PTP contained that upstream transmission is got off.Generally speaking, the network that is used for the PTP transmission is not to work in perfect condition, and it comprises many shakes of not planning, these shakes have significant effects for the precision of PTP.Therefore, FPGA need provide corresponding soft algorithm according to the situation of heterogeneous networks, thereby guarantees that it can recover high precision time.

Oscillator is another core component of system.FPGA adjusts oscillator by microcontroller after PTP is handled.The utility model adopts constant-temperature crystal oscillator OCXO, and this oscillator adopts temperature-control circuit to keep crystal and Key Circuit to be operated in the environment of an accurate constant temperature.FPGA and microcontroller collaborative work are controlled OCXO, guarantee the stability of OCXO frequency output.

The utility model is converted to the DCLS time with PTP network time and exports, and DCLS is a kind of digitally encoded signal with regular coding form, and the coding of this signal generates by FPGA, exports by drive circuit.Except that exporting the DCLS, according to user's actual requirement, this equipment can also output AC IRIG-B sign indicating number.Simultaneously, 10MHz and the 1PPS signal directly exported by FPGA have high precision, and 1PPS can directly be used for reflecting the available accuracy of this equipment, detects use for the user.

Claims

One kind network time signal change direct current timing code device, comprise control unit, it is characterized in that, control unit connects physical layer transceiver, mac controller, microcontroller, oscillator, filter and drive circuit, drive circuit and LED light respectively, physical layer transceiver connects the RJ45 interface, mac controller and microcontroller connect external microprocessor module by usb hub respectively, and microcontroller connects the FPGA Configuration Control Unit, and by mould/number conversion circuit connection oscillator.
2. a kind of network time signal commentaries on classics direct current timing code device as claimed in claim 1 is characterized in that described control unit is FPGA.