The devices and methods therefor of detecting long term frequency stability of clock
Technical field
The present invention relates to the computer communication technology field, relate in particular to a kind of devices and methods therefor of detecting long term frequency stability of clock.
Background technology
SDH (synchronous transmission series) equipment is present main telecom transmissioning equipment, a most important character of this kind equipment just is based on clock synchronization, its clock module has tracking, maintenance and three kinds of mode of operations of free oscillation, related advisory requirement according to ITU (International Telecommunications Union (ITU)), maximum frequency deviation can not be greater than 0.37ppm under the maintenance pattern for the SDH clock, and maximum frequency deviation can not be greater than 4.6ppm under free-run mode.
Demand in view of above-mentioned requirement and practical application, an important test event to testing equipment the time is exactly that the frequency stability of clock module under maintenance pattern and free-run mode tested (more than or equal to 24 hours) for a long time, so that obtain the degree of stability data of clock frequency, promptly obtain the frequency accuracy of clock.Frequency accuracy is used to describe the actual frequency of clock and the extent of deviation of nominal frequency (being ideal frequency).Because test result all is based on and finishes certain observing time, therefore for the signal that certain phase jitter and drift are arranged, the frequency accuracy confidence level of the longer test of Measuring Time is just higher.
At present, at SDH equipment carry out method of testing that this test adopts be per at least 30 minutes to the correspondent frequency data sampling once, promptly provide real-time frequency numerical value, by actual frequency values of artificial per 30 minutes records by frequency meter; Then,, depict the frequency stability curve of clock, record minimax frequency deviation value according to the frequency data of being sampled.Therefore, the long clock rate testing method that prior art adopted can't regularly be gathered, handle, add up data and real-time depiction goes out the frequency stability curve; And method of testing is loaded down with trivial details, sampled data is not enough, test result is not directly perceived, is difficult to guarantee higher measuring accuracy.
Summary of the invention
The devices and methods therefor that the purpose of this invention is to provide a kind of detecting long term frequency stability of clock can regularly be gathered, handle, add up data and real-time depiction goes out the frequency stability curve, thereby guarantees the measuring accuracy to clock.
The object of the present invention is achieved like this: a kind of device of detecting long term frequency stability of clock comprises:
Frequency meter: be used to receive clock signal to be measured, and after the frequency of test clock signal to be measured, measured value exported;
Digital sampling and processing: be used for the frequency data of the clock signal to be measured of receive frequency meter output, and these data are carried out statistical treatment, the frequency data after the processing are sent to the data processing output module;
The data processing output module: be used for frequency data are after treatment carried out the frequecy characteristic information of the clock signal to be measured in the overall treatment generation certain hour section, and output.
Described digital sampling and processing comprises:
Data acquisition submodule: be used for the initialization of frequency meter, the setting of parameter information and the reception of clock signal to be measured;
Data computation submodule: be used to calculate each eigenwert of the frequency of the clock signal to be measured in the certain hour section, comprise the maximal value of calculating the frequency of clock signal to be measured in the certain hour section, value, mean value etc.
Described data processing output module comprises:
The data processing submodule: the frequency data information after the processing that is used for the data acquisition processing module is sent is put in order to generate the graph data under each time scale;
Generate figure historical data display sub-module: the graph data under each time scale that is used for the data processing submodule is generated carries out overall treatment, forming the graph data of the clock signal to be measured in the certain hour section, and together show output with historical data.
Described digital sampling and processing and data output processing module are arranged in the computing machine, and link to each other with frequency meter by serial port.
What the reference clock of described frequency meter adopted is the clock of following the tracks of rubidium frequency standard.
The method of the detecting long term frequency stability of clock that a kind of device that utilizes the described detecting long term frequency stability of clock of claim 1 is realized comprises:
A, frequency meter are gathered clock signal to be measured, and test its frequency values;
B, frequency meter send to digital sampling and processing with the frequency values of the clock signal to be measured that test obtains, and by digital sampling and processing these data are carried out computing;
C, data output processing module carry out overall treatment to the frequency data that receive after digital sampling and processing is handled, and with the graph data of the frequency values that generates the clock signal to be measured in the certain hour section, and this graph data and historical data are shown output.
Described step b comprises:
The frequency values of the clock signal to be measured that b1, frequency meter regularly will record sends to computing machine by the RS-232 serial ports;
Data acquisition submodule receive frequency data in b2, the computing machine, and deliver to the data computation submodule and carry out computing comprise the maximal value of calculating the frequency of clock signal to be measured in the certain hour section, value, mean value.
Described step c comprises:
C1, data processing submodule are handled the result of calculation of data computation submodule, generate the graph data under each time scale;
C2, the graph data under each time scale is carried out overall treatment, to obtain the graph data of the frequency of clock signal to be measured in the certain hour section;
C3, the historical data that the above-mentioned graph data that obtains and data computation submodule are calculated show and export on the computer display.
By technique scheme as can be seen, the present invention adopts computing machine to carry out the processing of test data, and therefore, it is big to have a sampled data output, and sampling time interval is littler, and test result is science, advantage such as objective more; And adopt computer testing to alleviate tester's labour intensity greatly, improved the test automation level; Process, handle, add up and draw testing later data, make test result more directly perceived; Realization of the present invention only need only increase a computing machine on original Manual Test Equipment basis and Serial Port Line gets final product, and realizes that cost is lower.In addition, the present invention adopts the high precision clock reference source of rubidium frequency standard clock as frequency meter, has guaranteed the precision of test, has satisfied SDH clock accuracy test request.
Description of drawings
Fig. 1 is the structural drawing of the device of detecting long term frequency stability of clock;
Fig. 2 is digital sampling and processing and the data output processing modular structure synoptic diagram that links to each other with frequency meter;
Fig. 3 is the process flow diagram of the method for detecting long term frequency stability of clock.
Embodiment
The present invention is used for the frequency of high precision clock is tested for a long time, and according to the data of being sampled, real-time depiction goes out the frequency stability curve of clock, writes down the minimax frequency deviation value of clock signal to be measured.
The device of detecting long term frequency stability of clock of the present invention as shown in Figure 1 and Figure 2, concrete structure comprises:
Frequency meter: be used to receive clock signal to be measured, and after the frequency of test clock signal to be measured, export measured value to digital sampling and processing; And what the reference clock of frequency meter adopted is the clock of following the tracks of rubidium frequency standard, to guarantee the accuracy of frequency stability measurement; It is the frequency meter of HP53132 than the model of the Hewlett-Packard Corporation of the high order of magnitude of clock accuracy under the SDH hold mode that the frequency that is adopted is counted clock accuracy;
Digital sampling and processing: be used to receive the frequency data of clock signal to be measured, and these data are carried out statistical treatment, the frequency data after the processing are sent to the data processing output module; Digital sampling and processing further comprises again:
Data acquisition submodule: be used for the initialization of frequency meter, the setting of parameter information and the reception of clock signal to be measured;
Parameter information comprises: the calculating and setting information of sampling time scale etc.;
Data computation submodule: each eigenwert that is used to calculate the frequency of the clock signal to be measured in the certain hour section;
The data processing output module: be used for frequency data are after treatment carried out the frequecy characteristic information of the clock signal to be measured in the overall treatment generation certain hour section, and output; The data processing output module further comprises again:
The data processing submodule: the frequency data information after the processing that is used for the data acquisition processing module is sent is put in order to generate the graph data under each time scale;
Generate figure historical data display sub-module: the graph data under each time scale that is used for the data processing submodule is generated carries out overall treatment, forming the graph data of the clock signal to be measured in the certain hour section, and together show output with historical data;
Digital sampling and processing described in the present invention and data output processing module are arranged in the computing machine, and link to each other with frequency meter by serial port; Wherein the SDH network element is exported clock to be measured, rubidium frequency standard output high accuracy clock reference source, offering frequency meter locks, to guarantee the precision of test, frequency meter links to each other with computing machine by the RS-232 mouth again, finish collection and transmission, by computing machine the data of being gathered are done further processing again data.
The method of the detecting long term frequency stability of clock that the device that utilizes above-mentioned detecting long term frequency stability of clock of the present invention is realized as shown in Figure 3, specifically may further comprise the steps:
Step 1: frequency meter is gathered the clock signal to be measured of SDH network element output, and tests the frequency values of this clock signal to be measured;
Step 2: the frequency values of the clock signal to be measured that frequency meter regularly will record sends to computing machine by the RS-232 serial ports;
Step 3: data acquisition submodule receive frequency data in the computing machine, and deliver to the data computation submodule and carry out computing comprise the maximal value of calculating the frequency of clock signal to be measured in the certain hour section, minimum value, mean value etc.;
Step 4: the data processing submodule is handled the result of calculation of data computation submodule, forms the numerical value of each scale graduation and time scale, to generate the graph data under each time scale;
Step 5: the graph data under each time scale is carried out overall treatment, to obtain the graph data of the frequency of clock signal to be measured in the certain hour section;
Step 6: the historical data that the above-mentioned graph data that obtains and data computation submodule are calculated shows and exports on the computer display, and this historical data can be the maximal value of the frequency of clock signal to be measured in this time period, minimum value, current frequency values and the time period length of test etc.;
The user operates by the operation keyboard or the mouse of computing machine, on different time scales or scale graduation, to switch, because the data of each time scale and scale graduation all calculate, like this, the graph data that the user needs just can switch between different time and scale graduation smoothly, and the various information of the frequency of clock signal to be measured are provided for the user easily.
Can realize gathering in real time the frequency data information of clock signal to be measured easily by said process the present invention, and draw out corresponding graphic data output according to this data message and be shown to the user, so that the user understands the frequency stability of clock signal to be measured.