外文翻譯---雙速mil-std-1553b兼容的光纖數(shù)據(jù)總線

1、<p>　　A DUAL SPEED, MIL-STD-1553B COMPATIBLE</p><p>　　FIBER OPTIC DATA BUS</p><p>　　M.S. Blaha. C.H. DeGennaro, S.F. Utley</p><p>　　AT&T Bell Laboratories </p><p

2、>　　Whippany, New Jersey 07981</p><p><b>　　Abstract</b></p><p>　　A demonstration system of a dual speed, fiber optic data bus is described. This work is based on a previously desc

3、ribed concept (1) which envisioned a data bus populated with MIL-STD-1553B avionic components which evolve as equipment is upgraded to higher data rates. </p><p>　　The approach described herein provides for

4、the coexistence of bus nodes operating at 1 Mb/s, and 20 Mb/s, on a single fiber bus medium. The 1 Mb/s interface of each node is 1553B compatible, making use of readily available hardware and software. Both exist

5、ing, 1 Mb/s 1553B compatible interfaces and new equipment operating at 20 Mb/s have been shown to work simultaneously on the single bus structure. The design provides a sound, low-risk method for transitioning

6、 from current 1Mb</p><p>　　Introduction</p><p>　　The AT&T Fiber Optic 1553/MSDRT Data Bus provides an efficient means of improving the data handling capabilities of the 1553B data bus. Thro

7、ugh the use of fiber optics and high speed digital multiplexing techniques, a single fiber optic bus can provide both 1 Mb/s and 20 Mb/s transmission capability when supported by 1553B bus hardware. The 20 Mb/s

8、operation is based on the Multiple Speed Data Rate Transmission (MSDRT) concept, which involves multiplexing 20 Mb/s data with standard 155</p><p>　　A dual speed single fiber transmission bus was chosen over

9、 an approach using separate busses for 1 Mb/s transmission and for higher speed transmission because the single fiber bus approach is more reliable, less expensive, and lighter weight. The fiber optic bus is c

10、ompatible with 1553B hardware, application and protocol software, and error handling routines, resulting in reduced cost and schedule impact for future technology upgrades. In addition, the use of fiber optics offers inh

11、er</p><p><b>　　Approach</b></p><p>　　The fiber optic data bus was designed to directly interface with existing 1553B bus controllers and remote terminal hardware. This was done to ta

12、ke advantage of existing technology and thereby reduce development time and cost. Operational control and error handling routines of the bus were accomplished by the 1553B application and protocol software. </p>&

13、lt;p>　　The bus is configured as a common point broadcast network capable of supporting up to 31 nodes. It is composed of Fiber Optic Interface Units (FOIUs), and an optical bus structure consisting of fiber

14、 optic cables, connectors, and dual-redundant passive star couplers. The 20Mb/s operation is based on the MSDRT concept, which involves the multiplexing of 20Mb/s Manchester encoded data in place of 1553B data

15、 words. The 20Mb/s transfers are initiated whenever the bus contr</p><p>　　Figure 1. Message Containing High-Speed Data</p><p>　　Figure 2 depicts the basic architecture of the 1553B MSDRT D

16、ata Bus. Each FOIU has an optical output and optical input, which are connected via fiber to the star coupler. FOIU outputs are connected to inputs of the transmissive star coupler, and the optical signal is distributed

17、 to all of its outputs. Each of the star coupler's outputs are subsequently connected by fiber back to the FOIU's inputs. This effectively forms an optical broadcast bus, which is identical in function to the 155

18、3B bus i</p><p>　　Figure 2. Fiber Optic Network Architecture</p><p>　　For purposes of increased reliability, the 1553B standard requires that the bus consist of dual-redundant transmission chan

19、nels. As a consequence, the fiber optic 1553Bl MSDRT Data Bus was configured as a dual-redundant system, as represented in Figure 3. All FOIUs actually consist of two separate channels, labeled A and B in

20、 the figure, each having a separate 1553B interface connection, and each having optical connections to separate star couplers.</p><p>　　Figure 3. Dual-Redundant Fiber Optic 15638/20-Mbit Bus Configur

21、ation</p><p>　　FOIUs are connected directly to 1553B I/O ports associated with user equipment, and provide the necessary translation of tri-level 1553B signal format to the bi-level optical format. In additi

22、on, the FOIU provides the optical transceiver function, which transmits and receives the optical signals on the fiber optic bus structure. This makes it possible to retrofit any system interconnected by a 1553B electr

23、ical bus with a fiber optic 1553B bus by merely replacing the wire portion of the </p><p>　　The demonstration system was developed as a direct replacement for the wire portion of any existing 1553B bus

24、. This required that the fiber optic bus interface directly with any 1553B I/O connector and be compatible with any legitimate 1553B interface level. In addition, the high-speed 20Mb/s test units were d

25、esigned to be operable with any 1553B device on the bus without causing disruption. A system configuration diagram of the fiber optic bus system is shown in F</p><p>　　Figure 4. Fiber Optic Bus

26、Configuration Showing High-Speed Test Set</p><p>　　Demonstration System Fiber Optic Bus Hardware </p><p>　　The demonstration system fiber optic bus structure was realized using readily available

27、 fiber optic components. A single bus structure was made up of connector fiber optic cables and a 16×16 port transmissive star coupler (expansion to a 32 port coupler is also considered to he feasible

28、). The FOIUs housed optical transmitters, optical receivers, low-speed logic and level-shift circuit boards, and where employed, the high-speed transmitter and receiver logic. In addition the units</p><p>　

29、　Each FOIU contained two logic boards, each serving one of the dual-redundant channels. Circuits were realized using Small Scale Integrated Transistor-Transistor Logic (SSI 'ITL) logic chips and discrete components.

30、Mounted on each of these boards was an optical transmitter and an optical receiver. Translation of this design to smaller versions such as a single SEM-E Module is feasible. </p><p>　　The optical transmitter

31、 chosen for this application was a high-radiance light emitting diode (LED).The diode was operated at less than full output, launching -5.5 dBm (average) optical power into 100 micron core fiber. </p><p&g

32、t;　　The dual speed optical receiver was packaged in a module measuring 3" × 1.5" × 0.5" for mounting onto the logic and level-shift board. This burst-capable device, developed by AT&T, as

33、 a sensitivity of approximately -34 dBm (average) for 10 -' Bit Error Rate (BER), and uses a simplified edge detection technique. Highly stable operation over a temperature range from -55°C to +85℃

34、has been demonstrated.</p><p>　　The fiber optic cable assemblies were fabricated using lengths of avionic fiber optic cable connectorized with the AT&T biconic connector. The cable contains 1001140

35、micron graded index fiber, and has been used in production AVS/B Harrier Ⅱ fighter aircraft.</p><p>　　Commercial 16×16 port transmissive star couplers installed with biconic couplers were purch

36、ased. The input to output- port loss exhibited by the star coupler was 13.5 dB±5 dB of loss. </p><p>　　High-speed Test Set</p><p>　　The high-speed test set was designed to prove

37、the feasibility of the MSDRT Concept. As the avionics used in the bus demonstration system consisted only of low-speed equipment associated with the 1553B bus, a tester was designed to exercise the high-sp

38、eed FOIUs. The test set consists of an FOIU containing a high-speed receiver board, an FOIU containing a high-speed transmitter board, and a high-speed tester, as indicated in Figures 4 and 5.</p><

39、p>　　During operation, the high-speed transmitter and receiver are associated with a remote terminal and the bus controller, respectively. The function of the tester is to generate the 20Mb/s pseudo-

40、random words to be transmitted by the FOIU containing the high-speed transmitter circuitry. High- speed data is actually transmitted when its associated 1553B remote terminal is commanded by the bus con

41、troller to send. The high-speed receiver associated with the b</p><p>　　Figure 5. Single Direction 20 Mb/s Data Transfer Sequence</p><p>　　from Remote Terminal to Bus Controller </p>

42、<p>　　Optical Power Budget</p><p>　　The optical power budget for the fiber optic bus system is tabularized in Table 1. The expected typical values were derived from quoted manufacturers'

43、; specifications. Expected worst case entries take into account component aging and temperature dependencies from -55℃ to +85℃ . The values listed in the last column were the results of measurements tak

44、en on both channels of 13 prototype units. Round-trip optical loss measurements were taken by connecting a so</p><p>　　Table 1. Prototype Optical Power Budget</p><p>　　雙速MIL-STD-1553B

45、兼容的光纖數(shù)據(jù)總線</p><p><b>　　摘要</b></p><p>　　一個示范系統(tǒng)的雙速度,光纖數(shù)據(jù)總線進行了描述。它主要是基于先前的概念進行工作的，這種概念想象數(shù)據(jù)總線是由MIL-STD-1553B總線的航空組件組成的，這種航空組件可隨著設備升級為更高的數(shù)據(jù)率。</p><p>　　這種方法的描述，在這個方面提供了用單一的光纖總線

46、為媒介，使總線節(jié)點在1 Mb/s和24 Mb/s并存運行，每一個1 Mb/s的接口是在1553B總線上兼容的，并且可以利用現(xiàn)成的硬件和軟件，目前已經(jīng)證實，1 Mb/s的1553B總線兼容接口和20Mb/s的新操作設備可以同時工作在單總線結(jié)構(gòu)上，這種設計為從目前1 Mb/s的設備過渡到一個合并了現(xiàn)存兼容的1553B總線和最新更高速度的一種統(tǒng)一的總線結(jié)構(gòu)提供了一種合理的，低風險的方法。</p><p><b&g

47、t;　　介紹</b></p><p>　　AT&T光學纖維的1553/MSDRT數(shù)據(jù)總線提供了一種有效的手段去提高1553B數(shù)據(jù)總線的數(shù)據(jù)的處理能力，通過使用光學纖維和高速數(shù)字復用技術(shù)，1553B總線硬件支持的單根光纖總線可以提供1Mb/s和20Mb/s的傳輸能力。20Mb/s的操作基于多種速度數(shù)據(jù)率的傳輸概念，其中涉及多路復用20Mb/s數(shù)據(jù)和標準1553B協(xié)議在一起，其方式對1Mb/s用戶

48、是不可見的。這種雙速能力在1553B的基礎(chǔ)上可以對現(xiàn)有的系統(tǒng)提供高速改造的能力，并且允許系統(tǒng)升級而變的更好。</p><p>　　一個雙速度單纖維傳輸總線被選中了，由于它使用了分離的總線為1Mb/s傳輸和更高的速度傳輸,因為單纖維總線的方法更可靠,價格也不太貴,重量更輕的。光纖技術(shù)的總線可以兼容1553B總線的硬件，應用，協(xié)議軟件和常規(guī)的錯誤處理，這使得降低了成本和進度，對未來技術(shù)的升級有很大的影響，另外，使用光

49、纖對電磁干擾、射頻干擾、電磁脈沖具有固有的免疫能力，既抗輻射。</p><p><b>　　方法</b></p><p>　　光纖數(shù)據(jù)總線接口被設計來直接與現(xiàn)有1553B總線控制器和遠程終端的硬件連接。這樣做的目的是利用現(xiàn)有的技術(shù),因而減少開發(fā)時間和成本。總線的操作控制和錯誤處理是由1553B的應用和協(xié)議軟件完成的。</p><p>　　總線配

50、置成了一個可以支撐31個節(jié)點的共同廣播網(wǎng)絡，它由光纖接口單元(FOIUs),和一種光學總線結(jié)構(gòu)組成的，這種光學總線包含有光纖電纜、連接器和雙冗余星型耦合器。20Mb/s的操作是基于多種速度數(shù)據(jù)率的傳輸?shù)母拍睿婕暗蕉喾N20Mb/s的曼徹斯特碼代替1553B的數(shù)據(jù)字。每當總線控制要求傳輸從一個有著高速附加電路的1553B到到另外一個有著相同配置的用戶時，20Mb/s的傳輸?shù)谋銜_始。圖1說明了當一個20Mb/s的數(shù)據(jù)嵌入到1Mb/s數(shù)據(jù)位

51、中時，一個典型的系統(tǒng)所用的格式。</p><p>　　圖1 包含高速數(shù)據(jù)的消息</p><p>　　圖2描述了1553B多種速度數(shù)據(jù)率的數(shù)據(jù)總線的基本結(jié)構(gòu)，每一個光纖接口單元都有一個光纖輸入和光纖輸出，通過光纖連接到星型耦合器上。光纖接口單元輸出連接到了傳輸星型耦合器的輸入，并且光信號分到所有的輸出。每一個星型耦合器的輸出被隨后連接回光纖接口單元的輸入。這就有效地形成了一個光廣播總線，其相

52、同的功能由1553B總線來代替。一個傳輸?shù)男切婉詈掀魈峁┝擞兄m當?shù)墓鈱W特性和最小損失影響，對系統(tǒng)的光學動態(tài)范圍的要求的一個被動傳輸路徑。</p><p>　　圖2 光學網(wǎng)絡體系結(jié)構(gòu)</p><p>　　為了提高可靠性的目的，1553B總線基準要求總線是由雙冗余通道構(gòu)成的，結(jié)果，光纖1553B的多數(shù)據(jù)速率傳輸數(shù)據(jù)總線配置成為了一個雙冗余系統(tǒng)，例如圖3.所有的光纖接口單元實際上包含這兩種分

53、離的通道，在圖中標記為A和B，每一種都已一個分離的1553B接口的連接方式，每一種都有光纖連接的分離星型耦合器。</p><p>　　圖3 雙冗余光纖15638/20Mbit的總線配置</p><p>　　光纖接口單元是直接連接到1553B的輸入輸出端口的與用戶相關(guān)的設備，并提供了必要的三電平的1553B信號格式和雙層的光學格式的轉(zhuǎn)化。此外，光纖接口單元提供了光收發(fā)功能，可以中光纖總線結(jié)構(gòu)

54、上傳輸和接收光學信號。這就使得它可以改造由1553B電氣總線的光纖1553B總線僅僅通過代替總線上光纖接口的電線部分和光總線結(jié)構(gòu)互聯(lián)的任何系統(tǒng)，光纖接口單元設計是用來處理1Mb/s和20Mb/s兩者之間的通訊，或者只有1Mb/s的傳輸，取決于他們應用的系統(tǒng)。</p><p>　　作為任何現(xiàn)存的1553B總線的電線部分直接的替代物，示范系統(tǒng)是非常成熟的。這就要求光纖總線接口直接可以和任何1553B的I/O連接器連接

55、，而且可以與任何合法的1553B接口電平相適應。此外，高速20Mb/s試驗裝置在設計上可以操作任何總線上的1553B裝置，而不會造成破壞。一個光纖總線系統(tǒng)的系統(tǒng)配置圖如圖3和圖4所示。圖3所示的為系統(tǒng)的兩種低速光纖接口單元信號輸出，而圖4描述的可能是同一系統(tǒng)，但用的是高速測試裝置來詳細描述的。</p><p>　　圖4 光纖總線配置展示的高速測試設備</p><p>　　示范系統(tǒng)光纖總線的

56、硬件</p><p>　　示范系統(tǒng)光纖總線的結(jié)構(gòu)可用現(xiàn)成的光纖器件來實現(xiàn)。一個單一的總線結(jié)構(gòu)是有個連接器光纜和一個16×16端口的傳輸星型耦合器組成的（擴展到32個端口的耦合器也是同樣的認為他是可行的）。光纖接口單元包含了光學傳輸器，光接收器，低速邏輯和電平轉(zhuǎn)換電路板，而且用到了高速發(fā)射機和接收機的邏輯。此外，這些單元包含了他們自己的電力供應。這些按在用戶外部家具設備上的單元已經(jīng)被證實了，并且可直接進入

57、1553B的連接器中。</p><p>　　每個光纖接口單元含有兩種邏輯板，每個服務一個雙冗余通道。電路實現(xiàn)了使用小規(guī)模集成晶體管邏輯電路（SSI’ITL）邏輯芯片和離散元件。安裝的每一種板是一種光發(fā)射機和光接收機。本系統(tǒng)的設計到較小的轉(zhuǎn)化版本如一個單一的SEM-E模塊是可行的。</p><p>　　這種應用所選擇的光發(fā)射機是一種高亮度的發(fā)光二極管（LED），二極管的操作比完全輸出小的多，

58、發(fā)射-5.5毫瓦分貝（平均）的光功率成100微米的核心纖維。</p><p>　　雙速光接收機時包裝在一個模塊測量3" × 1.5" × 0.5"，用于安裝在邏輯和轉(zhuǎn)換電平板。這種功能強大的設備研制開發(fā)的AT&T，作為一個接近-34毫瓦分貝（平均）的靈敏度10誤碼率（BER），并采用簡化的邊緣檢測算法。已經(jīng)證實可以在一個溫度范圍從-55℃到+85％高度穩(wěn)定

59、運行。</p><p>　　光纖電纜組件是由長距離的航電光纜插頭的AT&T雙椎體的接插件組成的。電纜包含1001140微米的梯度折射率纖維，廣泛的應用于生產(chǎn)AVS/B鷂Ⅱ戰(zhàn)斗機。</p><p>　　商業(yè)16×16端口傳輸星型耦合器安裝了雙椎體的耦合器被購買了，輸入對輸出的損失表現(xiàn)在星型耦合器13.5dB±5 dB的損失。</p><p>

60、;<b>　　高速測試機組</b></p><p>　　設計了高速測試集來驗證其可行性多數(shù)據(jù)速率傳輸?shù)母拍睢ｋS著航空電子設備的應用包括在總線上演示系統(tǒng)的低速設備只與之關(guān)聯(lián)的1553B總線,檢驗員研制設計了高速的光纖接口單元。測試裝置由一個包含高速接收器的光纖接口單元,一個包含高速發(fā)射機光纖接口單元板,和快速測試儀組成，如圖4和圖5所示。</p><p>　　在運行過程

61、中,高速發(fā)射機和接收機分別連接一個遠程終端和總線控制器。該測試儀的功能來產(chǎn)生20Mb/s的偽隨機字傳送給含有高速電路的發(fā)射機光纖接口單元。高速數(shù)據(jù)實際被遠程終端及其相關(guān)1553B總線控制器所請求而發(fā)送。與之相關(guān)聯(lián)的高速總線控制器接收、發(fā)送接收高速的字,該測試儀的高速數(shù)據(jù)進行驗證,并把總線控制器一連串的“假”的字來維持通常總線的運行。該測試儀進行了一個字節(jié)一個字節(jié)比較的高速數(shù)據(jù)傳輸在總線上有接受到的數(shù)據(jù)。完整的信息轉(zhuǎn)移的數(shù)量是顯示在檢測器

62、的顯示屏上以及任何錯誤檢測。圖5給出了消息序列在組成高速測試機組的元件之間的傳輸。</p><p>　　圖5 單一方向的20mb/s數(shù)據(jù)傳輸序列從遠程終端到總線控制</p><p>　　光纖總線系統(tǒng)的光功率預算列表顯示在表1。預期的典型值都是來自引用制造商的規(guī)格說明書。預期最壞情況的記錄考慮構(gòu)件老化和從-55℃到+ 85℃的溫度依賴性。列在最后一欄的價值標準是對所采取的兩個通道的13個原