CN106444351A - Multi-source decoding timing system and working method thereof - Google Patents
Multi-source decoding timing system and working method thereof Download PDFInfo
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- CN106444351A CN106444351A CN201610752876.0A CN201610752876A CN106444351A CN 106444351 A CN106444351 A CN 106444351A CN 201610752876 A CN201610752876 A CN 201610752876A CN 106444351 A CN106444351 A CN 106444351A
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- G—PHYSICS
- G04—HOROLOGY
- G04R—RADIO-CONTROLLED TIME-PIECES
- G04R20/00—Setting the time according to the time information carried or implied by the radio signal
- G04R20/02—Setting the time according to the time information carried or implied by the radio signal the radio signal being sent by a satellite, e.g. GPS
- G04R20/04—Tuning or receiving; Circuits therefor
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- G—PHYSICS
- G04—HOROLOGY
- G04R—RADIO-CONTROLLED TIME-PIECES
- G04R20/00—Setting the time according to the time information carried or implied by the radio signal
- G04R20/02—Setting the time according to the time information carried or implied by the radio signal the radio signal being sent by a satellite, e.g. GPS
- G04R20/06—Decoding time data; Circuits therefor
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- Radar, Positioning & Navigation (AREA)
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- Position Fixing By Use Of Radio Waves (AREA)
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Abstract
The invention provides a multi-source decoding timing system and a working method thereof. The multi-source decoding timing system comprises a GPS (Global Positioning System) signal receiving device, a GPS signal timing output device, an IRIG-B (Inter-range Instrumentation Group-B) signal receiving device, an IRIG-B signal timing output device and a CPU (Central Processing Unit), wherein the GPS signal receiving device, the GPS signal timing output device, the IRIG-B signal receiving device and the IRIG-B signal timing output device are respectively connected with the CPU. The multi-source decoding timing system can simultaneously receive GPS signals and IRIG-B code signals, adopts two kinds of mutually-spare signals for timing, sufficiently utilizes the advantages of two timing modes, and effectively overcomes the defects of the two timing modes.
Description
Technical field
The present invention relates to time dissemination system field, decode time dissemination system and its method of work particularly to a kind of multi-source.
Background technology
In power system, unified high precision clock is for the running state information obtaining in generating set running
Extremely important.By trend curve (inclusion real-time tendency curve and historical trend to control system recording events time device
Curve) analysis it can be determined that accident occur sequencing, thus searching cause of accident.This for search cause of accident, point
Analysis accident generating process, thus reduce accident potential, the stability of raising system equipment has vital effect.State at present
The most time service mode of inside and outside application is gps satellite time service and IRIG-B code time service.Gps satellite time signal mostlys come from U.S.
The global positioning system (GPS) of state, this system operates in the satellite in 6 geocentric orbit planes by 24 and forms, this system
Receiver can receive the accurately temporal information to nanosecond (ns) level, and timing accuracy is very accurate.IRIG(Inter-Range
Instrumentation Group) be target range commandant committee of the U.S. affiliated institutions.This IRIG time standard code division is big for two
Class, a class is parallel time form type code, and transmission range is nearer；One kind is serial time form type code, point six kinds of lattice of A, B, D, E, G, H
Formula, it main difference is that timing code frame rate is different.The frame rate of IRIG-B code is 1 frame/second, carries and contains much information, and band is wide,
It is applied to long-distance transmissions.
The principle of gps satellite time service is first to use gps satellite antenna to receive satellite-signal, through GPS, signal is entered
After row parsing, sent to single-chip microcomputer using universal serial bus sending method, after single-chip microcomputer decoding, send according to specific agreement
To pair when equipment, deadline time service.The timing code for B form that IRIG timing code generally utilizes, i.e. IRIG-B timing code, letter
Claim B code.This timing code is mainly made up of the different pulse of some pulsewidths.The time service principle of this timing code, that is, pass through controller
The pulse signal that capture parsing receives, parses temporal information therein according to the standard agreement of IRIG-B code, then passes through logical
Equipment when communication interface is sent to pair, completes time service.
Gps time signal is serial signal, has got final product the reception of pair signals with RS-232 transceiver, from GPS
The signal time sending is very short, is received using interrupt mode, is easy for completing with single-chip microcomputer, relatively simple.
The many of complexity are then wanted in the parsing of IRIG-B code, and its timing code is a series of continuous pulses composition, and middle do not have interval, if will
Capture time code is accomplished by ceaselessly, and it is larger to take resource, generally to adopting fpga chip the parsing of such time signal more,
Fpga chip is parallel schema, can use different pins to process same information simultaneously, but FPGA operation is more complicated, difficulty is relatively
High.
The parsing of this two classes timing code therefore to be completed, generally will individually be made in different time service equipments, that is, a kind of
Time service equipment only completes a kind of parsing of signal, if there are equipment need GPS time service, some equipment need IRIG-B code time service
If, both time service equipments can only be installed simultaneously, time signal is changed, equipment is also required to change therewith, and installation operation compares
Loaded down with trivial details, cost is larger.
Content of the invention
In order to solve above-mentioned installation both time service equipments simultaneously, time signal is changed, and equipment is also required to change therewith, peace
Dress operates comparatively laborious, the larger technical problem of cost, and the present invention provides one kind need not install both time service equipments simultaneously, when
Between signal need not change, equipment need not be changed, and installation operation is simple, cost less multi-source decoding time dissemination system and its work side
Method.
The present invention provide multi-source decoding time dissemination system include gps signal reception device, gps signal time service output device,
IRIG-B signal receiving device, IRIG-B signal time service output device and CPU, described gps signal reception device, described GPS letter
Number time service output device, described IRIG-B signal receiving device and described IRIG-B signal time service output device respectively with described
CPU connects.
Decode in a kind of preferred embodiment of time dissemination system in the multi-source that the present invention provides, described gps signal time service output
Device, described IRIG-B signal time service output device all include RS-232 EBI, RS-484 EBI and CAN and connect
Mouthful.
Decode in a kind of preferred embodiment of time dissemination system in the multi-source that the present invention provides, described gps signal reception device
Including GPS, RS-232 incoming line, GPS isolating chip and RS-232 input pin, described GPS with described
RS-232 incoming line connects, and described GPS isolating chip leads to located at described RS-232 incoming line, described RS-232 incoming line
Cross described RS-232 input pin to be connected with described CPU, described CPU includes gps signal frame head time detecting unit, described GPS
Signal frame head time detecting unit is decoded to gps time signal or verifies.
Decode in a kind of preferred embodiment of time dissemination system in the multi-source that the present invention provides, described IRIG-B signal receives dress
Put including RS-422 transceiver, RS-422 incoming line, optical coupling isolator and IRIG-B input capture pin, described RS-422 receives
Send out device to be connected with described IRIG-B input capture pin by described RS-422 incoming line, described optical coupling isolator is located at described
RS-422 incoming line, described IRIG-B input capture pin is connected with described CPU, and described IRIG-B input capture pin is double
The capture pin of edge acquisition mode, described CPU includes IRIG-B signal frame head time detecting unit, described IRIG-B signal frame
Head time detecting unit is decoded to IRIG-B time signal or verifies.
The described multi-source that the present invention provides decodes the method for work of time dissemination system, the work side of the mastery routine of described CPU
Method comprises the steps：
Step one, work start, and CPU initializes, each system module initialization；
Step 2, open each functional module and interrupt, detected whether that time signal sends, without time signal, verified
Whether system time is correct, and system time as being correct, then sends system time information, and system time is for example incorrect, then continue
Detect whether that time signal sends, if there are time signal, then entered step 3；
Step 3, detection signal are the gps time signals being sent by UART, or the IRIG-B time being sent by CAN believes
Number, UART sending signal or CAN sending signal are entered with next step and is decoded or the positioning that verifies and signal transmission processe；
Whether step 4, first detection UART sending signal or CAN sending signal position, if positioned, sending signal,
If do not positioned, return determination time signal species in described step 3, if signal sends successfully, in completing this time
Make, if signal sends unsuccessfully, again detected whether that time signal sends.
Decode in a kind of preferred embodiment of method of work of time dissemination system in the multi-source that the present invention provides, the GPS of described CPU
The method of work of timing code decoding program comprises the steps：
Step one, proceed by gps time code decoding program；
Whether step 2, detection UART sending signal overflow, and if any spilling, labeling position position, such as non-spill are overflowed in detection,
Enter next step；
Step 3, write data into input register, and detect whether frame head, such as no frame head, return described step 2, such as
There is frame head, enter next step；
Step 4, pulse per second (PPS) flag bit set, solution is separated by decantation to UTC time, or when UTC time can be converted into specific
Between, such as it is converted into Beijing time；
Step 5, UTC time or special time are put into transmitter register, transmission time information；
Step 6, data output, depositor resets.
Decode in a kind of preferred embodiment of method of work of time dissemination system in the multi-source that the present invention provides, described CPU's
The method of work of IRIG-B timing code decoding program comprises the steps：
Step one, proceed by IRIG-B timing code decoding program；
Step 2, capture pulse, and horizontal pulse width analysis are rushed in input capture depositor middle arteries；
Step 3, pulse-width are respectively 8MS, 5MS and 2MS and carry out data analysiss, and parse the time of IRIG-B
Information, if not being 8MS, 5MS, 2MS pulse width, then enters capture and interrupts；
Step 4, output time information, and enter capture interruption.
Decode in a kind of preferred embodiment of method of work of time dissemination system in the multi-source that the present invention provides, in described step 2
Capture pulse and pulse width analysis are specially：Including rising edge acquisition mode, trailing edge acquisition mode and bilateral edge capture mould
Formula, by the value of free counter timer during trailing edge acquisition mode, deducts free counter timer during rising edge acquisition mode
Value, you can obtain the pulse width of high level pulse, obtain the required time by judging the high-level pulse width that obtains
Information；By bilateral along acquisition mode when detect rising edge capture depositor lifting endpoint value, and trailing edge capture depositor
Decline endpoint value, by lifting endpoint value deduct decline endpoint value can obtain pulse width time value.
Decode in a kind of preferred embodiment of method of work of time dissemination system in the multi-source that the present invention provides, in described step 3
8MS analysis is specially：
Step 3 one, to judge whether continuously to connect a pulse be 8MS, if it is not, then data break, marker is 2, will
Marker entry time information analysis working area, if it is, labelling reference pulse, and enter next step；
Step 3 two, initialization data Bcode, and the numerical value that the pulse labeling of subsequent capture is 0 and 1 is stored in array
Bcode, and parse the temporal information of IRIG-B code.
Decode in a kind of preferred embodiment of method of work of time dissemination system in the multi-source that the present invention provides, in described step 3
5MS, 2MS analysis is specially：If pulse width is 5MS, marker is 1, and is stored in array Bcode, then by labelling arteries and veins
Rush in angle of incidence information analysis working area；If pulse width is 2MS, marker is 0, and is stored in array Bcode, then will
Marker entry time information analysis working area.
With respect to prior art, the multi-source decoding time dissemination system of the present invention has following beneficial effect：
First, during a kind of multi-source time service based on GPS and IRIG-B code, bulk cargo is put, when this device detects and captures GPS letter
Number when, time service is carried out to external equipment using GPS time service mode；When receiving IRIG-B code, using IRIG-B code time service mode；
If be detected simultaneously by two kinds of signals, because IRIG-B code carries more times and control information, time service precision is higher, therefore
Using the external time service of IRIG-B code time service mode；When two kinds of signals all cannot detect, the output system time.Thus realize right
Outer time service uninterrupted it is ensured that the output of time signal can be realized in all cases, improve time dissemination system stability and
Reliability.
System adopts modular construction, including passage during 2 road CAN output pair, 3 road RS-485,2 road RS-232 serial communications
Pair when passage, a road IRIG-B code input channel, 1 tunnel pulse per second (PPS) output channel, 1 road sectors rushes output channel, 1 tunnel warning output
Passage.Module can be concurrently accessed GPS and 1 road IRIG-B code external synchronization signal, standby each other.During work, module both can be followed the tracks of
Gps satellite obtains accurate time, positional information it is also possible to receive IRIG-B code signal acquisition temporal information, passes through after parsing
CAN and serial ports isolation outwards export.When module normally receives gps satellite timing signal and IRIG-B (DC RS-422) time-code,
, as the external time reference of master clock, GPS time-code is as standby for the second synchronizing signal that IRIG-B (DC RS-422) sends.When
During GPS step-out, the time signal of IRIG-B (DC) interface is preferably as the external time reference of master clock.
The system completes the decoding process of two kinds of signals using a single-chip microcomputer, and single-chip microcomputer is passed through in the parsing of gps signal
Completing, the parsing of IRIG-B code is then to be realized by the edge capturing function of single-chip microcomputer to RS-232 transceiver.
2nd, timing code Analytic principle
(1) gps time code Analytic principle
The gps time form type code that GPS sends is the signal of Transistor-Transistor Logic level, and this signal enters after isolating chip
The RS-232 input pin SIN0 of single-chip microcomputer, by frame head and the interval of detection signal, solves time signal and check code part,
Pass through RS-232 EBI, RS-484 EBI, the external output time information of CAN interface after calculating through single-chip microcomputer,
Produce PPS pps pulse per second signal and minute pulse signal, when carrying out verification pair for external equipment simultaneously.
Gps time code decoding program is：
Decoding process calls UART interrupt routine to realize by single-chip microcomputer.Two are had inside MB90F543G single-chip microcomputer
Individual UART interrupt control register UART0 and UART1, gps time code is received by UART0.Single-chip microcomputer receives
Gps data is " $ GPRMC " frame format, for example：
$GPRMC,235953.031,V,0000.0000,N,00000.0000,E,,,270908,,,N*7B
After the UART0 data register of single-chip microcomputer receives data message, first determine whether the data frame header receiving
Point, i.e. " $ GPRMC ", then according to gps signal, the standard of each data bit is defined, parse year, month, day, hour, min, second respectively
Temporal information and check code part, if verification is correct, the temporal information parsing are sent out by external sendaisle
Go.
(2) IRIG-B time format code demodulation principle
Because IRIG-B code is direct current DC pulse, need to identify representated by pulse by the dutycycle detecting each pulse
Different implications.After RS-422 transceiver and light-coupled isolation device, the input capture accessing single-chip microcomputer draws IRIG-B code
Foot INT7, by capture pin be set to bilateral along acquisition mode, deducted with the numerical value in depositor during trailing edge and post during rising edge
Numerical value in storage obtains the width value of this pulse, then according to the definition of IRIG-B code each position code, identifies IRIG-B code
Frame head part, then demodulates temporal information, passes through RS-232 EBI, RS-484 EBI, CAN interface respectively
Externally output time information, also produces PPS pps pulse per second signal and minute pulse signal simultaneously, and it is right to carry out verifying for external equipment
When.
IRIG-B time format code decoding program is：
IRIG-B code is a series of pulse composition that cycles are 10ms, and the key of decoding is the dutycycle of measurement pulse.This
System be by the input capture functions of modules in single-chip microcomputer capture input signal level edge come decision level width
Mode judging IRIG-B code dutycycle, and then judge the implication of each pulse, thus parsing the scheme of temporal information to solve
Analysis IRIG-B code.2 road input capture function registers are had, input capture depositor has defeated in 3 inside MB90F543G single-chip microcomputer
Enter acquisition mode：Rising edge acquisition mode, trailing edge acquisition mode and bilateral along acquisition mode.Input capture unit is used as capture
The saltus step of incoming level, if effective edge edge is detected, by set interrupt identification, and by that time 16 free counter timers
Count value is stored in capture depositor.Deduct free counter timer during rising edge with the value of counter timer free during trailing edge
Value can get the pulse width of high level pulse, obtains required time letter by the high-level pulse width judging to obtain
Breath.
By the input capture controller of single-chip microcomputer be set to bilateral along acquisition mode, when single-chip microcomputer detects rising edge,
Record value rising_edge of input capture depositor, when single-chip microcomputer detects trailing edge, record input capture at that time
Value falling_edge of depositor, the value of the value as falling_edge of pulse width pulse_clocks deducts
The value of rising_edge.
IRIG-B (DC) time-code, according to IEEE Std 1344-1995 standard output per second one frame, comprises 100 code elements, often
Individual code element 10ms.
It is defined as follows：
“0”：First high level continues 2ms, and rear low level continues 8ms
“1”：First high level continues 5ms, and rear low level continues 5ms
“p”：First high level continues 8ms, and rear low level continues 2ms
The previous bit of the reference position (being its time reference point) of IRIG-B code is P code, and datum mark bit is also a P
Code.And continuously two or more P codes in no other any positions in IRIG-B code sequence.Continuous by finding out
In IRIG-B code, continuous two P codes are it may be determined that go out the starting point of IRIG-B code.Crystal oscillator used by single-chip microcomputer is 16MHZ crystal oscillator, heavy duty
The time cycle of angle of incidence intervalometer setting is 2us.IRIG-B code code element information p parsing represents.When monolithic machine testing
During to P code, p set 2；When being consecutively detected two P codes, IRIG-B code original bench mark point mark pr set 1, then solve successively
Separate out the other information of the IRIG-B code code element in this second subsequent.Parse when, minute, second be standard Greenwich mean time
Between, year information only have rear two information (such as 2013, comprise only year information 13 in code element, parsing display send the year letter
Front two information need to be added during breath), and natural law is the total natural law starting to current time from January 1 this year, needs to add natural law
Natural law is converted into current date information by exchange program.
3rd, system adopts RS-232 universal serial bus, RS-485 bus, the external time service of three kinds of communication modes of CAN, is provided with
2 tunnel RS-232 interface, 3 road RS485 interfaces and 2 tunnel CAN interfaces, interface resource enriches, and is applicable to most of time services and sets
Standby, have wide range of applications.
System mastery routine is mainly used to carry out system initialization work to MB90F543G single-chip microcomputer, including correlation function mould
The mode of operation of block selects, and interrupts setting etc.；The interrupt identification that constantly detection interrupt routine returns, and according to these interrupt identifications
Make corresponding interruption reaction.
Gps signal and IRIG-B code signal can be connected to simultaneously, carry out time service using two kinds of signals, two kinds of signals are standby each other
With, the advantage taking full advantage of mode when two kinds pairs, and effectively prevented the shortcoming of mode when two kinds pairs, there is very high pushing away
Wide value.
The system adopts modularized design, is directly received using the UART pin interface of single-chip microcomputer and is sent by GPS
GPS time information, design is simple, and position-sensitive is rapid, and after software program carries out time calibration, output time error exists
Delicate level, complies fully with the demand of currently most of time service equipments.In terms of IRIG-B code decoding, mainly pass through single-chip microcomputer
Input capture function captures IRIG-B code signal pulse, and most work is also to be realized by software, after being easy to system
The maintenance upgrade of phase, effectively reduces the design difficulty of system；Simultaneously because signal is through RS-422 receptor, through numeral every
From after be directly entered single-chip microcomputer and carried out data processing, decrease transmission time on hardware circuit for the signal, improve the time
Degree of accuracy；Avoid the external interference being subject to due to Chief Signal Boatswain time tranfer process, improve the capacity of resisting disturbance of system.
The system adopts a piece of single-chip microcomputer, is simultaneously achieved the work(of parsing gps time signal and IRIG-B time format code
Can, that is, achieve the multi-source input of signal.System can be concurrently accessed GPS and 1 road IRIG-B code external synchronization signal, standby each other.
During work, module both can have been followed the tracks of gps satellite and obtained accurate time, positional information it is also possible to reception IRIG-B code signal obtains
Take temporal information, pass through CAN after parsing and serial ports isolation outwards exports.When module normally receive gps satellite timing signal and
During IRIG-B (DC RS-422) time-code, second synchronizing signal that IRIG-B (DC RS-422) sends is as the external time of master clock
Benchmark, GPS time-code is as standby.When GPS step-out, the time signal of IRIG-B (DC) interface is preferably as master clock
External time reference.Simultaneity factor peripheral communication interfaces enrich, and can carry out RS232, RS485 and double CAN communication simultaneously, basic culvert
Cover currently popular both at home and abroad interface communication way, can be in multiple sector application such as electric power, communication, exploration.
Brief description
For the technical scheme being illustrated more clearly that in the embodiment of the present invention, will make to required in embodiment description below
Accompanying drawing be briefly described it should be apparent that, drawings in the following description are only some embodiments of the present invention, for
For those of ordinary skill in the art, on the premise of not paying creative work, can also be obtained other according to these accompanying drawings
Accompanying drawing, wherein：
Fig. 1 is the structural representation that the multi-source that the present invention provides decodes time dissemination system one preferred embodiment；
Fig. 2 is the work side of the mastery routine of described CPU of method of work that the multi-source that the present invention provides decodes time dissemination system
The flow chart of method；
Fig. 3 is the gps time code decoding program of the described CPU of method of work that the multi-source shown in Fig. 2 decodes time dissemination system
Method of work flow chart；
Fig. 4 is the IRIG-B timing code decoding journey of the described CPU of method of work that the multi-source shown in Fig. 2 decodes time dissemination system
The flow chart of the method for work of sequence.
Specific embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete
Site preparation describes it is clear that described embodiment is only a part of embodiment of the present invention, rather than whole embodiments.It is based on
Embodiment in the present invention, it is all other that those of ordinary skill in the art are obtained under the premise of not making creative work
Embodiment, broadly falls into the scope of protection of the invention.
Refer to Fig. 1, be the structural representation that the multi-source that the present invention provides decodes time dissemination system one preferred embodiment.
Described multi-source decoding time dissemination system 1 include gps signal reception device 11, gps signal time service output device 12,
IRIG-B signal receiving device 13, IRIG-B signal time service output device 14 and CPU15.Described gps signal reception device 11, institute
State gps signal time service output device 12, described IRIG-B signal receiving device 13 and described IRIG-B signal time service output device
14 are connected with described CPU15 respectively.
Described gps signal time service output device 12, that described IRIG-B signal time service output device equal 14 includes RS-232 is total
Line interface 20, RS-484 EBI 30 and CAN interface 40.
Described gps signal reception device 11 includes GPS 111, RS-232 incoming line 112, GPS isolating chip
113 and RS-232 input pins 114.Described GPS 111 is connected with described RS-232 incoming line 112, described GPS every
Located at described RS-232 incoming line 112, described RS-232 incoming line 112 passes through described RS-232 input and draws off-chip piece 113
Foot 114 is connected with described CPU15.Described CPU15 includes gps signal frame head time detecting unit 151, described gps signal frame head
Time detecting unit 151 is decoded to gps time signal or verifies.
Described IRIG-B signal receiving device 13 include RS-422 transceiver 131, RS-422 incoming line 132, optocoupler every
From device 133 and IRIG-B input capture pin 134.Described RS-422 transceiver 131 pass through described RS-422 incoming line 132 with
Described IRIG-B input capture pin 134 connects, and described optical coupling isolator 133 is located at described RS-422 incoming line 132, described
IRIG-B input capture pin 134 is connected with described CPU15, and described IRIG-B input capture pin 134 is bilateral along capture mould
The capture pin of formula, described CPU15 includes IRIG-B signal frame head time detecting unit 152, during described IRIG-B signal frame head
Between detector unit 152 IRIG-B time signal is decoded or verifies.
See also Fig. 2, Fig. 3 and Fig. 4, wherein Fig. 2 is the work side that the multi-source that the present invention provides decodes time dissemination system
The flow chart of the method for work of the mastery routine of described CPU of method；Fig. 3 is the work side that the multi-source shown in Fig. 2 decodes time dissemination system
The flow chart of the method for work of gps time code decoding program of the described CPU of method；Fig. 4 is the multi-source decoding time service system shown in Fig. 2
The flow chart of the method for work of IRIG-B timing code decoding program of the described CPU of method of work of system.
Described multi-source decodes in the method for work of time dissemination system, the method for work of mastery routine S1 of described CPU include as
Lower step：
Step S11, work start, and CPU initializes, each system module initialization；
Step S12, open each functional module and interrupt, detected whether that time signal sends, without time signal, verified
Whether system time is correct, and system time as being correct, then sends system time information, and system time is for example incorrect, then continue
Detect whether that time signal sends, if there are time signal, then entered step 3；
Step S13, detection signal are the gps time signals being sent by UART, or the IRIG-B time being sent by CAN believes
Number, UART sending signal or CAN sending signal are entered with next step and is decoded or the positioning that verifies and signal transmission processe；
Whether step S14, first detection UART sending signal or CAN sending signal position, if positioned, sending signal,
If do not positioned, return determination time signal species in described step 3, if signal sends successfully, in completing this time
Make, if signal sends unsuccessfully, again detected whether that time signal sends.
Method of work S41 of the gps time code decoding program of described CPU comprises the steps：：
Step S411, proceed by gps time code decoding program；
Whether step S412, detection UART sending signal overflow, and if any spilling, labeling position position is overflowed in detection, such as no overflows
Go out, enter next step；
Step S413, write data into input register, and detect whether frame head, such as no frame head, return described step 2,
If any frame head, enter next step；
Step S414, pulse per second (PPS) flag bit set, solution is separated by decantation to UTC time, or when UTC time can be converted into specific
Between, such as it is converted into Beijing time；
Step S415, UTC time or special time are put into transmitter register, transmission time information；
Step S416, data output, depositor resets.
Method of work S42 of the IRIG-B timing code decoding program of described CPU comprises the steps：
Step S421, proceed by IRIG-B timing code decoding program；
Step S422, capture pulse, and horizontal pulse width analysis are rushed in input capture depositor middle arteries；It is specially：
Including rising edge acquisition mode, trailing edge acquisition mode and bilateral along acquisition mode, by trailing edge acquisition mode
When free counter timer value, deduct the value of free counter timer during rising edge acquisition mode, you can obtain high level arteries and veins
The pulse width of punching, obtains required temporal information by the high-level pulse width judging to obtain；By bilateral along acquisition mode
When detect rising edge capture depositor lifting endpoint value, and trailing edge capture depositor decline endpoint value, end will be lifted
Point value deducts decline endpoint value and can obtain pulse width time value；
Step S423, pulse-width are respectively 8MS, 5MS and 2MS and carry out data analysiss, and parse IRIG-B when
Between information, if not being 8MS, 5MS, 2MS pulse width, then enter capture interrupt；It is specially：
8MS analysis is specially：
Step one, to judge whether continuously to connect a pulse be 8MS, if it is not, then data break, marker is 2, will mark
Note pulse entry time information analysis working area, if it is, labelling reference pulse, and enter next step；
Step 2, initialization data Bcode, and the numerical value that the pulse labeling of subsequent capture is 0 and 1 is stored in array
Bcode, and parse the temporal information of IRIG-B code.
5MS, 2MS analysis is specially：If pulse width is 5MS, marker is 1, and is stored in array Bcode, then
By marker entry time information analysis working area；If pulse width is 2MS, marker is 0, and is stored in array
Bcode, then by marker entry time information analysis working area.
Step S424, output time information, and enter capture interruption.
The multi-source decoding time dissemination system 1 of the present invention has following beneficial effect：
First, a kind of multi-source time dissemination system device 1 based on GPS and IRIG-B code, when this device detects and captures GPS letter
Number when, time service is carried out to external equipment using GPS time service mode；When receiving IRIG-B code, using IRIG-B code time service mode；
If be detected simultaneously by two kinds of signals, because IRIG-B code carries more times and control information, time service precision is higher, therefore
Using the external time service of IRIG-B code time service mode；When two kinds of signals all cannot detect, the output system time.Thus realize right
Outer time service uninterrupted it is ensured that the output of time signal can be realized in all cases, improve time dissemination system stability and
Reliability.
System adopts modular construction, including passage during 2 road CAN output pair, 3 road RS-485,2 road RS-232 serial communications
Pair when passage, a road IRIG-B code input channel, 1 tunnel pulse per second (PPS) output channel, 1 road sectors rushes output channel, 1 tunnel warning output
Passage.Module can be concurrently accessed GPS and 1 road IRIG-B code external synchronization signal, standby each other.During work, module both can be followed the tracks of
Gps satellite obtains accurate time, positional information it is also possible to receive IRIG-B code signal acquisition temporal information, passes through after parsing
CAN and serial ports isolation outwards export.When module normally receives gps satellite timing signal and IRIG-B (DC RS-422) time-code,
, as the external time reference of master clock, GPS time-code is as standby for the second synchronizing signal that IRIG-B (DC RS-422) sends.When
During GPS step-out, the time signal of IRIG-B (DC) interface is preferably as the external time reference of master clock.
The system completes the decoding process of two kinds of signals using a single-chip microcomputer, and single-chip microcomputer is passed through in the parsing of gps signal
Completing, the parsing of IRIG-B code is then to be realized by the edge capturing function of single-chip microcomputer to RS-232 transceiver.
2nd, timing code Analytic principle
(1) gps time code Analytic principle
The gps time form type code that GPS sends is the signal of Transistor-Transistor Logic level, and this signal enters after isolating chip
The RS-232 input pin SIN0 of single-chip microcomputer, by frame head and the interval of detection signal, solves time signal and check code part,
Pass through RS-232 EBI, RS-484 EBI, the external output time information of CAN interface after calculating through single-chip microcomputer,
Produce PPS pps pulse per second signal and minute pulse signal, when carrying out verification pair for external equipment simultaneously.
Gps time code decoding program is：
Decoding process calls UART interrupt routine to realize by single-chip microcomputer.Two are had inside MB90F543G single-chip microcomputer
Individual UART interrupt control register UART0 and UART1, gps time code is received by UART0.Single-chip microcomputer receives
Gps data is " $ GPRMC " frame format, for example：
$GPRMC,235953.031,V,0000.0000,N,00000.0000,E,,,270908,,,N*7B
After the UART0 data register of single-chip microcomputer receives data message, first determine whether the data frame header receiving
Point, i.e. " $ GPRMC ", then according to gps signal, the standard of each data bit is defined, parse year, month, day, hour, min, second respectively
Temporal information and check code part, if verification is correct, the temporal information parsing are sent out by external sendaisle
Go.
(2) IRIG-B time format code demodulation principle
Because IRIG-B code is direct current DC pulse, need to identify representated by pulse by the dutycycle detecting each pulse
Different implications.After RS-422 transceiver and light-coupled isolation device, the input capture accessing single-chip microcomputer draws IRIG-B code
Foot INT7, by capture pin be set to bilateral along acquisition mode, deducted with the numerical value in depositor during trailing edge and post during rising edge
Numerical value in storage obtains the width value of this pulse, then according to the definition of IRIG-B code each position code, identifies IRIG-B code
Frame head part, then demodulates temporal information, passes through RS-232 EBI, RS-484 EBI, CAN interface respectively
Externally output time information, also produces PPS pps pulse per second signal and minute pulse signal simultaneously, and it is right to carry out verifying for external equipment
When.
IRIG-B time format code decoding program is：
IRIG-B code is a series of pulse composition that cycles are 10ms, and the key of decoding is the dutycycle of measurement pulse.This
System be by the input capture functions of modules in single-chip microcomputer capture input signal level edge come decision level width
Mode judging IRIG-B code dutycycle, and then judge the implication of each pulse, thus parsing the scheme of temporal information to solve
Analysis IRIG-B code.2 road input capture function registers are had, input capture depositor has defeated in 3 inside MB90F543G single-chip microcomputer
Enter acquisition mode：Rising edge acquisition mode, trailing edge acquisition mode and bilateral along acquisition mode.Input capture unit is used as capture
The saltus step of incoming level, if effective edge edge is detected, by set interrupt identification, and by that time 16 free counter timers
Count value is stored in capture depositor.Deduct free counter timer during rising edge with the value of counter timer free during trailing edge
Value can get the pulse width of high level pulse, obtains required time letter by the high-level pulse width judging to obtain
Breath.
By the input capture controller of single-chip microcomputer be set to bilateral along acquisition mode, when single-chip microcomputer detects rising edge,
Record value rising_edge of input capture depositor, when single-chip microcomputer detects trailing edge, record input capture at that time
Value falling_edge of depositor, the value of the value as falling_edge of pulse width pulse_clocks deducts
The value of rising_edge.
IRIG-B (DC) time-code, according to IEEE Std 1344-1995 standard output per second one frame, comprises 100 code elements, often
Individual code element 10ms.
It is defined as follows：
“0”：First high level continues 2ms, and rear low level continues 8ms
“1”：First high level continues 5ms, and rear low level continues 5ms
“p”：First high level continues 8ms, and rear low level continues 2ms
The previous bit of the reference position (being its time reference point) of IRIG-B code is P code, and datum mark bit is also a P
Code.And continuously two or more P codes in no other any positions in IRIG-B code sequence.Continuous by finding out
In IRIG-B code, continuous two P codes are it may be determined that go out the starting point of IRIG-B code.Crystal oscillator used by single-chip microcomputer is 16MHZ crystal oscillator, heavy duty
The time cycle of angle of incidence intervalometer setting is 2us.IRIG-B code code element information p parsing represents.When monolithic machine testing
During to P code, p set 2；When being consecutively detected two P codes, IRIG-B code original bench mark point mark pr set 1, then solve successively
Separate out the other information of the IRIG-B code code element in this second subsequent.Parse when, minute, second be standard Greenwich mean time
Between, year information only have rear two information (such as 2013, comprise only year information 13 in code element, parsing display send the year letter
Front two information need to be added during breath), and natural law is the total natural law starting to current time from January 1 this year, needs to add natural law
Natural law is converted into current date information by exchange program.
3rd, system adopts RS-232 universal serial bus, RS-485 bus, the external time service of three kinds of communication modes of CAN, is provided with
2 tunnel RS-232 interface, 3 road RS485 interfaces and 2 tunnel CAN interfaces, interface resource enriches, and is applicable to most of time services and sets
Standby, have wide range of applications.
System mastery routine is mainly used to carry out system initialization work to MB90F543G single-chip microcomputer, including correlation function mould
The mode of operation of block selects, and interrupts setting etc.；The interrupt identification that constantly detection interrupt routine returns, and according to these interrupt identifications
Make corresponding interruption reaction.
Gps signal and IRIG-B code signal can be connected to simultaneously, carry out time service using two kinds of signals, two kinds of signals are standby each other
With, the advantage taking full advantage of mode when two kinds pairs, and effectively prevented the shortcoming of mode when two kinds pairs, there is very high pushing away
Wide value.
The system adopts modularized design, is directly received using the UART pin interface of single-chip microcomputer and is sent by GPS
GPS time information, design is simple, and position-sensitive is rapid, and after software program carries out time calibration, output time error exists
Delicate level, complies fully with the demand of currently most of time service equipments.In terms of IRIG-B code decoding, mainly pass through single-chip microcomputer
Input capture function captures IRIG-B code signal pulse, and most work is also to be realized by software, after being easy to system
The maintenance upgrade of phase, effectively reduces the design difficulty of system；Simultaneously because signal is through RS-422 receptor, through numeral every
From after be directly entered single-chip microcomputer and carried out data processing, decrease transmission time on hardware circuit for the signal, improve the time
Degree of accuracy；Avoid the external interference being subject to due to Chief Signal Boatswain time tranfer process, improve the capacity of resisting disturbance of system.
The system adopts a piece of single-chip microcomputer, is simultaneously achieved the work(of parsing gps time signal and IRIG-B time format code
Can, that is, achieve the multi-source input of signal.System can be concurrently accessed GPS and 1 road IRIG-B code external synchronization signal, standby each other.
During work, module both can have been followed the tracks of gps satellite and obtained accurate time, positional information it is also possible to reception IRIG-B code signal obtains
Take temporal information, pass through CAN after parsing and serial ports isolation outwards exports.When module normally receive gps satellite timing signal and
During IRIG-B (DC RS-422) time-code, second synchronizing signal that IRIG-B (DC RS-422) sends is as the external time of master clock
Benchmark, GPS time-code is as standby.When GPS step-out, the time signal of IRIG-B (DC) interface is preferably as master clock
External time reference.Simultaneity factor peripheral communication interfaces enrich, and can carry out RS232, RS485 and double CAN communication simultaneously, basic culvert
Cover currently popular both at home and abroad interface communication way, can be in multiple sector application such as electric power, communication, exploration.
The foregoing is only embodiments of the invention, not thereby limit the present invention the scope of the claims, every using this
Equivalent structure or equivalent flow conversion that bright description and accompanying drawing content are made, or directly or indirectly it is used in the skills of other correlations
Art field, is included within the scope of the present invention.
Claims (10)
1. a kind of multi-source decoding time dissemination system is it is characterised in that include gps signal reception device, gps signal time service output dress
Put, IRIG-B signal receiving device, IRIG-B signal time service output device and CPU, described gps signal reception device, described GPS
Signal time service output device, described IRIG-B signal receiving device and described IRIG-B signal time service output device respectively with described
CPU connects.
2. multi-source according to claim 1 decoding time dissemination system it is characterised in that described gps signal time service output device,
Described IRIG-B signal time service output device all includes RS-232 EBI, RS-484 EBI and CAN interface.
3. multi-source decoding time dissemination system according to claim 1 is it is characterised in that described gps signal reception device includes
GPS, RS-232 incoming line, GPS isolating chip and RS-232 input pin, described GPS and described RS-
232 incoming lines connect, and described GPS isolating chip passes through located at described RS-232 incoming line, described RS-232 incoming line
Described RS-232 input pin is connected with described CPU, and described CPU includes gps signal frame head time detecting unit, described GPS letter
Number frame head time detecting unit is decoded to gps time signal or verifies.
4. multi-source according to claim 1 decoding time dissemination system is it is characterised in that described IRIG-B signal receiving device bag
Include RS-422 transceiver, RS-422 incoming line, optical coupling isolator and IRIG-B input capture pin, described RS-422 transceiver
It is connected with described IRIG-B input capture pin by described RS-422 incoming line, described optical coupling isolator is located at described RS-
422 incoming lines, described IRIG-B input capture pin is connected with described CPU, and described IRIG-B input capture pin is bilateral
Along the capture pin of acquisition mode, described CPU includes IRIG-B signal frame head time detecting unit, described IRIG-B signal frame head
Time detecting unit is decoded to IRIG-B time signal or verifies.
5. in a kind of Claims 1-4 multi-source described in any one decode time dissemination system method of work it is characterised in that
The method of work of the mastery routine of described CPU comprises the steps：
Step one, work start, and CPU initializes, each system module initialization；
Step 2, open each functional module and interrupt, detected whether that time signal sends, without time signal, check system
Whether the time is correct, and system time as being correct, then sends system time information, and system time is for example incorrect, then continue detection
Whether there is time signal to send, if there are time signal, then enter step 3；
Step 3, detection signal are the gps time signals being sent by UART, or the IRIG-B time signal being sent by CAN, right
UART sending signal or CAN sending signal enter next step and are decoded or the positioning that verifies and signal transmission processe；
Whether step 4, first detection UART sending signal or CAN sending signal position, if positioned, sending signal, if
Do not position, then return determination time signal species in described step 3, if signal sends successfully, make in completing this time, such as
Fruit signal sends unsuccessfully, then again detected whether that time signal sends.
6. multi-source according to claim 5 decodes the method for work of time dissemination system it is characterised in that during the GPS of described CPU
Between the method for work of code decoding program comprise the steps：
Step one, proceed by gps time code decoding program；
Whether step 2, detection UART sending signal overflow, and if any spilling, labeling position position, such as non-spill are overflowed in detection, enter
Next step；
Step 3, write data into input register, and detect whether frame head, such as no frame head, return described step 2, if any frame
Head, enters next step；
Step 4, pulse per second (PPS) flag bit set, solution is separated by decantation to UTC time, or UTC time can be converted into special time, such as
It is converted into Beijing time；
Step 5, UTC time or special time are put into transmitter register, transmission time information；
Step 6, data output, depositor resets.
7. multi-source according to claim 5 decodes the method for work of time dissemination system it is characterised in that the IRIG- of described CPU
The method of work of B timing code decoding program comprises the steps：
Step one, proceed by IRIG-B timing code decoding program；
Step 2, capture pulse, and horizontal pulse width analysis are rushed in input capture depositor middle arteries；
Step 3, pulse-width are respectively 8MS, 5MS and 2MS and carry out data analysiss, and parse the temporal information of IRIG-B,
If not being 8MS, 5MS, 2MS pulse width, then enter capture and interrupt；
Step 4, output time information, and enter capture interruption.
8. multi-source according to claim 7 decodes the method for work of time dissemination system it is characterised in that catching in described step 2
Obtain pulse and pulse width analysis are specially：Including rising edge acquisition mode, trailing edge acquisition mode and bilateral along acquisition mode,
By the value of free counter timer during trailing edge acquisition mode, deduct free counter timer during rising edge acquisition mode
Value, you can obtain the pulse width of high level pulse, obtains required time letter by the high-level pulse width judging to obtain
Breath；By bilateral along acquisition mode when the lifting endpoint value that rising edge captures depositor is detected, and trailing edge captures depositor
Decline endpoint value, lifting endpoint value is deducted decline endpoint value and can obtain pulse width time value.
9. multi-source according to claim 7 decodes the method for work of time dissemination system it is characterised in that in described step 3
8MS analysis is specially：
Step 3 one, to judge whether continuously to connect a pulse be 8MS, if it is not, then data break, marker is 2, by labelling
Pulse entry time information analysis working area, if it is, labelling reference pulse, and enter next step；
Step 3 two, initialization data Bcode, and the numerical value that the pulse labeling of subsequent capture is 0 and 1 is stored in array Bcode,
And parse the temporal information of IRIG-B code.
10. multi-source according to claim 7 decodes the method for work of time dissemination system it is characterised in that in described step 3
5MS, 2MS analysis is specially：If pulse width is 5MS, marker is 1, and is stored in array Bcode, then by labelling arteries and veins
Rush in angle of incidence information analysis working area；If pulse width is 2MS, marker is 0, and is stored in array Bcode, then will
Marker entry time information analysis working area.
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