Aircraft Systems - Integrated Modular Avionics (ATA 42) PDF

Fundamentals M13 AIRCRAFT AERODYNAMICS, STRUCTURES and SYSTEMS Rev.-ID: 1JAN2014 Author: WaH For Training Purposes Only ©LTT Release: Mar. 11,...

Fundamentals M13 AIRCRAFT AERODYNAMICS, STRUCTURES and SYSTEMS Rev.-ID: 1JAN2014 Author: WaH For Training Purposes Only ©LTT Release: Mar. 11, 2014 M13.20 Integrated Modular Avionics ATA 42 EASA Part-66 CAT B2 M13.20 42 B2 E Training Manual For training purposes and internal use only. © Copyright by Lufthansa Technical Training (LTT). LTT is the owner of all rights to training documents and training software. Any use outside the training measures, especially reproduction and/or copying of training documents and software − also extracts there of − in any format at all (photocopying, using electronic systems or with the aid of other methods) is prohibited. Passing on training material and training software to third parties for the purpose of reproduction and/or copying is prohibited without the express written consent of LTT. Copyright endorsements, trademarks or brands may not be removed. 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Lufthansa Technical Training Dept HAM US Lufthansa Base Hamburg Weg beim Jäger 193 22335 Hamburg Germany Tel: +49 (0)40 5070 2520 Fax: +49 (0)40 5070 4746 E-Mail: [email protected] www.Lufthansa-Technical-Training.com Revision Identification: The date given in the column ”Revision” on the face of Dates and author’s ID, which may be given at the base The LTT production process ensures that the Training this cover is binding for the complete Training Manual. of the individual pages, are for information about the Manual contains a complete set of all necessary pages latest revision of that page(s) only. in the latest finalized revision. Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS (ATA42) M11.19|M12.17|M13.20 M13 AIRCRAFT AERODYNAMICS, STRUCTURE AND SYSTEMS M13.20 INTEGRATED MODULAR AVIONICS (ATA 42) FOR TRAINING PURPOSES ONLY! FRA US/O-5 WeR Jun 15, 2013 ATA DOC Page 1  AIRCRAFT SYSTEMS Lufthansa Technical Training EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS (ATA42) M11.19|M12.17|M13.20 M11A TURBINE AEROPLANE AERODYNAMICS, STRUCTURES AND SYSTEMS M11.19 INTEGRATED MODULAR AVIONICS (ATA 42) The Integrated Modular Avionics (IMA) concept, which replaces numerous separate processors and line replaceable units (LRU) with fewer, more centralized processing units, is promising significant weight reduction and maintenance savings in the new generation of commercial airliners. Boeing said by using the IMA approach it was able to shave 2,000 pounds off the avionics suite of the new 787 Dreamliner, due to fly in August, versus previous comparable aircraft. Airbus said its IMA approach cuts in half the part numbers of processor units for the new A380 avionics suite. "It’s not just the IMA modules themselves, and reducing the number of LRUs. IMA brings a more efficient network for the aircraft," The central ideal of IMA is the sharing of hardware; that is, many FOR TRAINING PURPOSESONLY! applications sharing the same processing unit. An IMA operator can upgrade software without having to upgrade the hardware, and vice versa, Thus, it is possible to reduce the cost with processors, wiring, I/O, etc. FRA US/O-5 WeR Jun 15, 2013 ATA DOC Page 1 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Introduction (ATA42) M11.19|M12.17|M13.20 INTRODUCTION IMA General (Less is More) Introduction Since the mid-1980’s the principle of modularisation of avionic functions has been increasing in importance. ▪ In the case of traditional LRUs (Line Replaceable Units) each computer has, as a rule, only one application. ▪ With IMA (Integrated Modular Avionics)several applications are combined in one box (in the A380 there are three). These are referred to as LRMs (Line Replaceable Modules). ▪ By integrating, the hardware functions can be better coordinated with each other and can be accomodated in the same space. ▪ With the modular structure, components can be used for a number of projects. This reduces the expense of development and the costs of certification. ▪ Modular structure with its defined interfaces means that individual modules can be replaced if necessary. ▪ As the lifetime of an aircraft is measured in decades, but electronic components last in general only for a period of years, this reduces the costs of providing for a large number of spare parts. ▪ The IMA concept was first employed by Boeing in the B777 and then by Airbus in the A380. It will also be used in the A400M military transporter and in the A350. ▪ Robust construction in the A400M leads to enhanced resistance to vibrations, improved lightning protection and FOR TRAINING PURPOSESONLY! increased EMV to fulfil the strict requirements for the military version of IMA. ▪ In the meanwhile, the avionics of all newly developed passenger aircraft, such as the Bombardier C-Series, the Comac C919 and the Irkut MS-21 are based on the IMA concept. ▪ By using IMA LRMs in the B787, Boeing was able to save nearly 1000 kg in weight. ▪ In the A380 Airbus managed to halve the number of processors in the computers. HAM US/O-6 SaR Sep 02, 2012 00| Intro|L1|A/B1/B2 Page 2 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Introduction (ATA42) M11.19|M12.17|M13.20 INTRODUCTION Contents of this book It is very difficult to put across basics from the topics prescribed by EASA. The various IMA concepts are all very aircraft type-specific. This book shows the different IMA concepts using examples from: Boeing 747−400 Boeing 777−300 Boeing 747−8 Airbus A380. In addition two different network types are explained with examples from the Boeing 777 and the Airbus A380. FOR TRAINING PURPOSESONLY! HAM US/O-6 SaR Sep 02, 2012 00| Intro|L1|A/B1/B2 Page 2 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Introduction (ATA42) M11.19|M12.17|M13.20 LRM FOR TRAINING PURPOSESONLY! Line Replaceable Module Figure 1 From LRUs to LRMs HAM US/O-6 SaR Sep 02, 2012 00| Intro|L1|A/B1/B2 Page 3 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Network Fundamentals (ATA42) M11.19|M12.17|M13.20 FOR TRAINING PURPOSESONLY! Figure 2 Ethernet Basics HAM US/O-6 SaR Sep 02, 2012 01| Ethernet Basics|L1|A/B1/B2 Page 5 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Network Fundamentals (ATA42) M11.19|M12.17|M13.20 NETWORK FUNDAMENTALS Ethernet Basics In the past, the aircraft avionics systems used primarily the ARINC 429 data busses to transfer information. It uses a data transport rate of up to 100 thousand bit per second or 1 kilo bps in short and allows a data exchange only in one direction (UNIDIRECTIONAL) Each individual avionics component needs a wired connection to all other computers that need the data, which is called a point−to−point interconnection. If for example a new LRU has to be added because of a modification you have to install new wires to all other involved computers. The classic ethernet−based data communication needs just a connection of each unit to the common ethernet bus, used for both transmission and reception (BIDERCTIONAL), and the data speed is increased up to 10 million bits per second or Mega bps in short. FOR TRAINING PURPOSESONLY! If a new LRU has to be added the hardware modification just needs a new connection to the ethernet bus. The ARINC 629 is an example of a common ethernet bus interconnection for aircraft data networks. HAM US/O-6 SaR Sep 02, 2012 01| Ethernet Basics|L1|A/B1/B2 Page 4 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Network Fundamentals (ATA42) M11.19|M12.17|M13.20 Classic Ethernet The classic ethernet−based communication is based on the so called CSMA / CD principle. CSMA stands for carrier sense multiple access and CD for collision detection. These communication rules are comparable to those which polite people use during a meeting. Multiple access means that anybody can talk to all people at the table and all can listen to the speaker at the same time. For the computer this also means that all have access to the ethernet bus at the same time. Carrier sense means that all people have to listen first and only start to speak if the medium is silent. Also the computer have to listen first and are only allowed to transmit data if the bus is empty. In a few cases it may happen that two transmitters, or people, start talking at the same time. In this case both detect this collision and stop the conversation immediately, this is called collision detection. After a few micro−seconds of listening the first computer starts to transmit again and the normal conversation continues. The waiting time is random so that never the same computers start the conversation again at the same time. FOR TRAINING PURPOSESONLY! The classic Ethernet is used in the Boeing 777. HAM US/O-6 SaR Sep 02, 2012 02| Classic Ethernet|L2|B1/B2 Page 6 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Network Fundamentals (ATA42) M11.19|M12.17|M13.20 FOR TRAINING PURPOSESONLY! Figure 3 Ethernet Basics / Classic Ethernet HAM US/O-6 SaR Sep 02, 2012 02| Classic Ethernet|L2|B1/B2 Page 7 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Network Fundamentals (ATA42) M11.19|M12.17|M13.20 Switched Ethernet (Half/Duplex) A problem with the classic ethernet is that if you have many computers you may get long waiting times to detect a silent medium that allows you to transmit the information. Therefore, if you have time critical data transmissions like in the avionics system, you need to divide the network with intermediate devices to regulate the traffic. On the A380, these intermediate devices are routers or switches, which have a dedicated segment for each computer. Now all computers can transmit data at any time and the router/switch transfers the data only to the receiver who needs the information. Here for example from computer 1 to computer 3. At the same time computer 5 could send data to computer 6. A collision is not possible, because the router/switch always buffers the data until the specific line is free. If for example computer 1 and computer 4 want to send data at the same time to computer 3, then the router/ switch buffers both data and transmit the data after each other. FOR TRAINING PURPOSESONLY! HAM US/O-6 SaR Sep 02, 2012 03| Switched Ethernet|L2|B1/B2 Page 8 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Network Fundamentals (ATA42) M11.19|M12.17|M13.20 FOR TRAINING PURPOSESONLY! Figure 4 Ethernet Basics / Switched Ethernet HAM US/O-6 SaR Sep 02, 2012 03| Switched Ethernet|L2|B1/B2 Page 9 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Network Fundamentals (ATA42) M11.19|M12.17|M13.20 Full Duplex Ethernet Full duplex operation mode can only be used when all of the following statements are fulfilled: The physical medium is capable of supporting simultaneous transmission and reception without interference. There are exactly two stations connected with a full duplex point−to−point link. Both stations are capable of use and have been configured to use full duplex operation. Since there is no use of a shared medium, the CSMA/CD principle is unnecessary. But if one of these conditions is not fulfilled the ethernet−based data communication works in half duplex operation, taking into account the CSMA/CD principle. The most common configuration for full duplex operation has a central intermediate device with a full duplex point−to−point link to each computer or other intermediate device. On the A380, the central intermediate devices are AFDX switches for the avionics world and routers for the open world. FOR TRAINING PURPOSESONLY! Both worlds use quad cables as full duplex point−to−point links. HAM US/O-6 SaR Sep 01, 2012 04| Full Duplex Ethernet|L2|B1/B2 Page 10 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Network Fundamentals (ATA42) M11.19|M12.17|M13.20 use, FOR TRAINING PURPOSESONLY! Figure 5 Ethernet Basics / Full Duplex Ethernet HAM US/O-6 SaR Sep 01, 2012 04| Full Duplex Ethernet|L2|B1/B2 Page 11 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 DATA BUS BASICS General Databus connections are used both internally in computers and externally for communication from computer to computer. In internal microcomputer operation parallel transfer of data takes place. The speed of internal data processing depends on the processor type (4 bits, 8 bits, 16 bits, 32 bits or 64 bits) and its clock frequency. The internal components (CPU, memory and interface) are connected to each other via buses, i. e. the data bus, the address bus and the control bus. The number of wires is determined by the type of processor. Outside the microcomputer data is exchanged in series (with the exception of a few interfaces used in parallel. Apart from the choice of CPU, the data transfer rate in bits/sec depends on the transport medium and the distance between the computers. FOR TRAINING PURPOSESONLY! HAM US/O-6 SaR Sep 02, 2012 01| DATA Bus Basics|L1|A/B1/B2 Page 12 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 THIS PAGE INTENTIONALLY LEFT BLANK FOR TRAINING PURPOSESONLY! HAM US/O-6 SaR Sep 02, 2012 01| DATA Bus Basics|L1|A/B1/B2 Page 13 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 Network Technologies General For the purpose of common communication on a network, the voltage levels, the signal type and data organisation (the protocol) must be compatible with both word length and word and bit synchronisation. Apart from common computer interfaces such as RS 232 (V24), or RS 422 (V11), the following are examples of network technologies, used not only in buildings and offices, but also in aviation. Token Ring (IEEE 802.4 /.5), a method of communication used by IBM, but now outdated (1980), whose data packets are passed from terminal to terminal on a ring-type data-line network. Mil-Std-1553, a method of communication used in military fighter aircraft, whereby the fire control computer is responsible for organising data transfer between the computers. ARINC 429, an old means of transferring data using the simplex (multi-simplex) method, but which is however still found on all aircraft using digital technology. The data content of each word is provided with identification, a so-called label. ARINC 629, a means of tranferring data using the duplex method, developed for the Boeing B777. Label words and assigned data words are organised as word strings/messages and frames. Ethernet (IEEE 802.3 / ARINC 646), an up-to-date duplex transmission method used in FOR TRAINING PURPOSESONLY! buildings/offices for local area networks (LANs), and also used in aviation technology. The data content is provided with a label. Switched Ethernet, using an assigned address the data is switched through to the appropriate receiver. AFDX, ARINC 664, avionics full duplex switched Ethernet, the communication architecture developed for the A380 with transmission and receiver lines and duplicated switches. HAM US/O-6 SaR Sep 02, 2012 02| Network Page 14 Technologies|L1|A/B1/B2 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 Network Technologies In addition there are databuses in the aircraft used only for limited tasks. such as: ARINC 659 backplane databus, as used in the newer generation of Boeing aircraft (display unit video buses). DSDL, Dedicated Serial Data Link, an internal display databus used by Airbus. CIDS Bus, cabin intercommunication data system used by Airbus. ARINC 636 OLAN, onbord local area network, which transfers data for the entertainment sysem using fibre optics, as in the B777, etc. ARINC 453, the WX bus from the weather radar transceiver to the display. ARINC 717, the databus to the flight recorder for logging flight data. Apart from the above listed network technologies for computer communication, there is a growing number of bus systems for home and building technologies, such as: EIB, European Installation Bus, developed in1987 by Siemens. LON, Local Operating Network, developed in1994 in America. LCN, Local Control Network, a German development, based on LON. Developed for the automotive industry by Bosch is: FOR TRAINING PURPOSESONLY! CAN (Controller Area Network) bus, developed in1983, used to monitor a large number of functions in road vehicles and which reduces the number of cable harnesses necessary. In the meantime this bus has become obligatory, but as manufacturers could not come to an agreement, three different data protocols are in use. This CAN bus is also used in the A 380 for controlling functions. HAM US/O-6 SaR Sep 02, 2012 02| Network Page 14 Technologies|L1|A/B1/B2 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 Bus Type Data Rate Word Length Voltage/Current Character 300 − 4800 b/s Asynchronous PC interface, simplex operation; RS 232 8 bits simplex +/- 12 V (V24) 9.600/38.400 b/s baud rate dependent on cable length (15 − 30m). Asynchronous interface for higher frequencies and longer distances than RS 232; RS 422 bis 100 Kbit/s +/- 4,6 V (V11) used for example in Airbus aircraft, such as the FWC−> DMC message bus. ARINC 429 LS 12 − 14 Kbit/s Multisimplex bus (up to 20 receivers) used in all aircraft with digital technology; shielded 32 bits +/- 10 V twisted-wire pair. ARINC 429 HS 100 Kbit/s Upto 31 computers can be time-coordinated by the fire control computer; shielded Mil Std 1553 1 Mbit/s 20 bits +/- 12,5 V twisted-wire pair. ARINC 629 Classic 2 MBit/s 20 bits +/- 50 mA Duplex bus for up to 120 receivers (B777) via a current mode coupler; twisted-wire pair. Ethernet Ethernet can be found in very different versions, as seen from the various data rates and word lengths. Apart from the different wire types, such as thick/thin coaxial cable, Ethernet 64 − 1518 +/- 2,5 V twisted/untwisted, shielded/unshielded wires, data is transferred via hubs or can be 10 M − 1 Gbit/s bytes (ARINC 646) (Light) switch-coordinated. Fast Ethernet is used for long distances in fibre optic cables. AFDX 100 Mbit/s II II Full duplex, such as switched Fast Ethernet ( 2 x 8 AFDX switches). DSDL 800 Kbit/s 25 bits +/- 12 V Simplex bus with alternate and feedback cables (Airbus). Duplex bus for the cabin intercommunication data system in Airbus aircraft; CIDS 4/5 Mbit/s 14 bits +/- 5 V data organisation into 256 subframes with 9 words per frame. FOR TRAINING PURPOSESONLY! OLAN (onbord local area network) forms, for example, the connection between cabin ARINC 636 Light LAN and the server using fibre optics. Simplex databus from the weather radar receiver/transmitter (WXR RT) to the cockpit ARINC 453 1 Mbit/s 1600 bits +/- 2,5 V display. 64/128/256 Simplex bus to the DFDR for recording data orgasnised in 4 subframes with 64/128/256 ARINC 717 Words/s 12 bits +/- 5 V words per frame. 10 Controller Area Network, asynchronous twisted duplex bus for controlling doors and CAN Kbit/s−1Mbit/s 130 bits +/- 5 V switches (up to 128 subscribers). Figure 6 Bus Types HAM US/O-6 SaR Sep 02, 2012 02| Network Page 15 Technologies|L1|A/B1/B2 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 ARINC 629 General The new ARINC 629 communication system is a high-integrity, high-reliability, multi-user data bus, which was first deployed on the Boeing 777 aircraft. Boeing began working on a concept of a multi-transmitter data bus in 1977. The ARINC 629 specification was adopted by Airlines Electronic Engineering Committee (AEEC) in 1989. ARINC 629 supports a multi-transmitter and bidirectional approach to digital data communications. The primary advantages of this multiple access data bus include the ability to move more data between LRU’s at higher rates using fewer wires. Unshielded Twisted pairs Another advantage of this concept is: it does not need a central bus controller, which could be a potential source of total data bus failure. ARINC Specifications 429 and 629 may both be applied on the same airplane in order to FOR TRAINING PURPOSESONLY! obtain the best technical and economic solution (which both are implemented in the 777). The data format used in ARINC 629 was inherited from Mil-Std-1553. HAM US/O-6 SaR Sep 02, 2012 03| ARINC 629|L1|A/B1/B2 Page 16 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 FOR TRAINING PURPOSESONLY! Figure 7 ARINC 629 − Basic Structure HAM US/O-6 SaR Sep 02, 2012 03| ARINC 629|L1|A/B1/B2 Page 17 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 Interconnection Serial Interface Module Data Transmission modes Terminal Controllers Basically three different Standards for data transmission are possible: Data Bus Simplex: One Transmitter, one Receiver. One Coupler ( Global Side ) Coupler Termination Way only. Termination Coupler Transmit Receive Resistor Half-Duplex: One Transmitter, one Receiver. both Resistor Stub Stub directions, but only one at a time. Full Duplex: One Transmitter, one Receiver. SIM both directions at the same time. Oscillator Oscillator A choice had to be made depending on the technical abilities and the individual requirements. Terminal Controller On ARINC 629 Duplex Operations had been selected. XPP RPP A Bi-Directional Communication is established but only in one direction at a time. System Terminal Transmission speed is 2 MBit/s. Memory Specifications allow up to120 LRU’s on a single data bus. FOR TRAINING PURPOSESONLY! These LRU’s have to share the bandwith of the data bus so LRU they have to transmit their information one after the other. (Local Side) LRU’s have to wait until a transmitting unit is through before transmitting their own information. All LRU’s read all the information transmitted and have to pick the information they require for further processing. Figure 8 Overview HAM US/O-6 SaR Sep 01, 2012 05| ARINC 629|L2|B1/B2 Page 18 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 Interconnection Serial Interface Module Terminal Controllers Data-BUS Types Three transmission modes and media are specified for the implementation of ARINC Data Bus 629 networks: Termination Coupler Coupler ( Global Side ) Coupler Termination Current Mode Bus, Resistor Transmit Receive Resistor Stub Stub Voltage Mode Bus, Fiber Optic Mode Bus. SIM Components Oscillator Oscillator Physically the ARINC 629 system consists of Terminal Controller the following components: XPP RPP Data Bus Cable, Couplers, System Memory Terminal Stub Cables FOR TRAINING PURPOSESONLY! LRU In addition to that two components integrated in (Local Side) the LRU also belong to the data bus: Figure 8 Overview HAM US/O-6 SaR Sep 01, 2012 05| ARINC 629|L2|B1/B2 Page 18 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 Termination Resistor LRU N-1 LRU N Data Bus Cable Current- Mode Couple r1 Stub Cable Terminal Controller Current-Mode Coupler N-1 FOR TRAINING PURPOSESONLY! Current-Mode Coupler N Serial Interface LRU 1 Module Termination Resistor Figure 9 Components HAM US/O-6 SaR Sep 01, 2012 05| ARINC 629|L2|B1/B2 Page 19 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 Data Bus with Current Couplers BUS-Cables Data transmission is in a serial mode. So the bus is a twisted pair wire which is terminated on both ends of the bus by a 130  Resistor. The Termination Resistor maximum length of an individual bus cable is limited to 100 Meters. Splices and Connectors In general, Boeing claims, the bus is not affected by splices and Data Cable connectors. On Boeing 777 the total amount of both the system busses has been limited to 5 splices and 3 connectors in order to keep up the reliability of the bus. The performance itself is not affected by these splices and connectors. Current Mode Couplers The Current Mode Coupler layout is designed for quick installation. They consist of a cover containing the electronics and a receptacle. An E-core assembly is a part of the coupler base. E-core assemblies are electromagnetic components that couple the signals in the data bus cable in and out of the coupler. The wire guides are grooves that give a controlled routing and protection for the wires of the data bus cable as they go through the E-core assembly. FOR TRAINING PURPOSESONLY! The housing itself is waterproof. Although there are different manufacture the couplers are fully compatible with each other and therefore are interchangeable. Current Mode Coupler The couplers are arranged in panels side by side and the bus cable is led through all the couplers without being cut. Figure 10 Data Bus with Current Coupler HAM US/O-6 SaR Sep 01, 2012 05| ARINC 629|L2|B1/B2 Page 20 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 Data Cable Coupler Base Stub Cable FOR TRAINING PURPOSESONLY! Wire Guides Current Mode Couplers Bus Panel (Cover removed) Stub Cables not connected yet! Figure 11 ARINC 629 − Current-Mode Coupler HAM US/O-6 SaR Sep 01, 2012 05| ARINC 629|L2|B1/B2 Page 21 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 Current-Mode Coupler Operations Description Operations Modes General The Current Mode Coupler together with the Serial Interface Normal Transmit Mode Operation Module (SIM) forms the interface between LRU and ARINC 629 The current mode coupler transmit drivers put signals on BUS. The coupler contains two redundant transmit and receive the data bus. The current mode coupler receives the channels to provide fault tolerance. The SIM selects the active voltage signals from the SIM over the transmit stub of channel. the stub cable. The current mode coupler puts the Purpose of the Current Couplers signals onto the data bus. Thus, it changes voltage The Current Couplers offer some advantages over a direct signals from the SIM to the current signals on the bus. connection of the LRU’s: Normal Receive Mode Operation Impedance transformation: adjusts the impedance of the LRU to the imdedance of the bus. The current mode coupler receives current mode Saves the bus from electrical faults from the stub or the LRU. signals from the bus. It changes them to voltage Increases the stub impedance and therefore reduces the signals which go to the SIM over the receive stub influence on the signals. of the stub cable. Finally, the Current Coupler prevents the bus from failures in Transmit Inhibit Mode Operation case an electrical fault occurs in the bus or a LRU. The SIM monitors the quality of the transmit signal from Power Supply FOR TRAINING PURPOSES ONLY! the LRU. If the signal is unsatisfactory, the SIM stops The Current Mode Coupler also contains a rectifier which transmit operation. The LRU continues to receive data generates a supply voltage from the signals transmitted by the during the transmit inhibit mode of operation. SIM. Control The SIM selects the active transmitter / receiver. A Logic inside the Coupler activiates the corresponding transmitter / receiver set. HAM US/O-6 SaR Sep 01, 2012 06| ARINC 629|L3|B2 Page 22 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 FOR TRAINING PURPOSES ONLY! Figure 12 ARINC 629 − Current-Mode Coupler HAM US/O-6 SaR Sep 01, 2012 06| ARINC 629|L3|B2 Page 23 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 Stub Cable The stub cables are for bi-directional data transfer between the LRU and the current-mode coupler. The stub cables also supplies power from the LRU’s to the current mode couplers. A stub cable has four wires; two to transmit and the two to receive. Stub cables can be as long as 15 meters for transmit/ receive couplers and 25 meters for receive-only couplers couplers. Its impedance is 50. FOR TRAINING PURPOSES ONLY! HAM US/O-6 SaR Sep 01, 2012 06| ARINC 629|L3|B2 Page 24 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 Data Cable Current Mode Couplers FOR TRAINING PURPOSES ONLY! Stub Cables Figure 13 ARINC 629 − Stub Cable HAM US/O-6 SaR Sep 01, 2012 06| ARINC 629|L3|B2 Page 25 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 The Serial Interface Module The SIM together with the current-mode coupler forms the interface between the ARINC 629 data bus cable and the terminal controller in an LRU. In transmit mode, the SIM changes transmit signals from the terminal controller into analogue voltage signals. It transfers these signals to the current-mode coupler via the transmit stub of the stub cable. In receive mode, the SIM receives the voltage signals from the current-mode coupler after the current-mode coupler changes the current-mode signals to voltage signals. The SIM changes the received voltage signals into transition signals and forwards them to the terminal controller. The SIM monitors the quality of its own transmit signal and tells the terminal controller about any problem. It does a check of the signal put on the data bus by the current-mode coupler. The SIM tells the terminal controller if the signal is not satisfactory. The SIM also monitors the quality of signals received from other LRUs. The Terminal Controller The ARINC 629 terminal controller transfers data to and from the LRU subsystem memory through the subsystem interface. The LRU transmit personality PROM (XPP) and receive personality PROM (RPP) control the flow of data. It indicates which parameter are to be transferred or to be evaluated. FOR TRAINING PURPOSES ONLY! The terminal controller gets its protocol access values from the XPP or the RPP. HAM US/O-6 SaR Sep 01, 2012 06| ARINC 629|L3|B2 Page 26 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 FOR TRAINING PURPOSES ONLY! Figure 14 ARINC 629 − LRU HAM US/O-6 SaR Sep 01, 2012 06| ARINC 629|L3|B2 Page 27 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 ARINC 629 on Boeing 777 The ARINC 629 System supports data communication between many terminals over a common bus. Boeing uses in there B777 up to eleven Current Mode Busses for different systems and only few Fiber Optic Mode Busses for test purposes: 3 dedicated ARINC 629 Flight Control Buses for Flight Control Systems connected with 24 LRU’s. 4 ARINC 629 System Buses (two on the left and two on the right side of the A/C) for the main Communication Systems connected with 39 LRU’s of the following systems – Avionics – Electrical – Electro-mechanical – Environmental Control – Propulsion. 4 ARINC 629 Inter-Cabin Buses connect the two AIMS cabinets (Airplane Information Management System) and the three CDU’s (Control Display Units). Most of the LRU’s are supplied with data from two or more busses tn order to have several FOR TRAINING PURPOSES ONLY! independent data inputs. HAM US/O-6 SaR Sep 02, 2012 09| ARINC 629 B777|L3|B2 Page 28 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 FOR TRAINING PURPOSES ONLY! Figure 15 B777 Interface Diagram HAM US/O-6 SaR Sep 02, 2012 09| ARINC 629 B777|L3|B2 Page 29 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 ONBOARD LOCAL AREA NETWORK - General Layout Purpose The Onboard Local Area Network (OLAN) is a fiber optic communications network. It moves digital data between Line Replaceable Units (LRUs). Fiber optic networks have these qualities: They carry more data than wire buses They weigh less than wire buses Electromagnetic radiation has no effect on the data. FOR TRAINING PURPOSES ONLY! HAM US/O-6 SaR Sep 01, 2012 10| OLAN1 B777|L1|A/B1/B2 Page 30 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 LRU LRU LRU ONBOARD LOCAL AREA NETWORK FOR TRAINING PURPOSES ONLY! LRU LRU LRU Figure 16 Onboard Local Area Network General Layout HAM US/O-6 SaR Sep 01, 2012 10| OLAN1 B777|L1|A/B1/B2 Page 31 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 Onboard Local Area Network (OLAN) The onboard Local area network (OLAN) is a fiber optic communications network. It transfers digital data between line replaceable units (LRUs). Fiber optic networks have these qualities: They carry more data than wire buses They weigh less than wire buses Electromagnetic radiation has no effect on the data. OLAN is used in two different LAN: The Avionics LAN The Cabin LAN. Every LAN consists of three components: A primary ring (PRI) A secondary ring (SEC) Two bypass switch units (BSUs). Both rings of a LAN are connected via a BSU. These interfaces permit these functions: Data load Tests Fault isolation. The avionics LAN connects these LRUs: Right AIMS cabinet Left AIMS cabinet Maintenance access terminal (MAT) Brouter. FOR TRAINING PURPOSES ONLY! The Cabin LAN connects: ZNTU 1 (Zone Network controller/ Telephone distribution Unit) ZNTU 2 ZNTU 3 CFS (Cabin File Server). HAM US/O-6 SaR Sep 01, 2012 11| OLAN2 B777|L3|B2 Page 32 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 FOR TRAINING PURPOSES ONLY! Avionics LAN Cabin LAN Figure 17 OLAN HAM US/O-6 SaR Sep 01, 2012 11| OLAN2 B777|L3|B2 Page 33 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 OLAN-Connectors OLAN uses two types of connectors, a type-A connector and a type-B connector. Type-A Connector The type-A connector is for production breaks that are not regularly connected and disconnected. The type-A connector is a multi-channel, in-line (butt type) connector. This connector has very low light loss between optical fiber components. Type-B Connector The type-B connector attaches a fiber optic cable to a line replaceable unit (LRU). The type-B connector is more frequently connected and disconnected than the type-A connector. The type-B connector is a multi-channel, expanded beam (ball Lens) connector. Light loss across this connector is low but not as low as in the type-A connector. WARNING: BEFORE OPENING THE CONNECTORS YOU SHOULD: DISCONNECT THE CABLE FROM THE EQUIPMENT ON BOTH ENDS OR SWITCH OFF THE SYSTEMS ATTACHED. The light is invisible but may be intense enough to damage the eyes! Before you install a FOR TRAINING PURPOSES ONLY! connector, examine it to make sure it is clean. Use only approved procedures to clean the connectors and the fiber optic lenses. Do not disconnect the connectors unless absolutely necessary. HAM US/O-6 SaR Sep 01, 2012 11| OLAN2 B777|L3|B2 Page 34 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 FOR TRAINING PURPOSES ONLY! Figure 18 OLAN Connectors HAM US/O-6 SaR Sep 01, 2012 11| OLAN2 B777|L3|B2 Page 35 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 THIS PAGE INTENTIONALLY LEFT BLANK FOR TRAINING PURPOSES ONLY! HAM US/O-6 SaR Sep 01, 2012 11| OLAN2 B777|L3|B2 Page 36 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS Data Bus Basics (ATA42) M11.19|M12.17|M13.20 FOR TRAINING PURPOSES ONLY! Figure 19 OLAN Fiber Optic Cable HAM US/O-6 SaR Sep 01, 2012 11| OLAN2 B777|L3|B2 Page 37 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS MAWEA B 747 (ATA42) M11.19|M12.17|M13.20 MODULARIZED AVIONICS WARNING ELECTRONIC ASSEMBLY (MAWEA) B747 General MAWEA and Card File At the end of the 1980’s Boeing began modularising systems in the B747−400 with plug-in cards. The so-called MAWEA bay and a card file were introduced. Both are located opposite each other on the sides of the nose gear bay, accessible through the two crawl ways. ARINC 429 buses form the connection to the aircraft systems. This chapter describes the tasks of the MAWEA and the card files using the examples of the B747−400, B747−8 and the B777. The MAWEA of the 747−8 is similar to the one of the 747−400. The connection to the aircraft systems is realized by ARINC 429. Figure 20 MAWEA Card File The schematic on the next page shows the integration of the FOR TRAINING PURPOSES ONLY! MAWEA into the aircraft systems of the B747−8. HAM US/O-6 SaR Sep 02, 2012 00| IMA MAWEA 744|L1|A/B1/B2 Page 38 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS MAWEA B 747 (ATA42) M11.19|M12.17|M13.20 FOR TRAINING PURPOSES ONLY! Figure 21 Modularized Avionics Warning Electronics Assembly B747−800 HAM US/O-6 SaR Sep 02, 2012 00| IMA MAWEA 744|L1|A/B1/B2 Page 39 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS MAWEA B 747 (ATA42) M11.19|M12.17|M13.20 Introduction B 747 General MAWEA Functions The Modularized Avionics Warning Electronic Assembly (MAWEA) is a card file containing cards that generate visible and audible The MAWEA card file performs these functions: flight deck warnings. Fire warning The MAWEA is located in the righthand crawlway of the Main Overspeed warning Equipment Center and contains 18 cards. The cards are readily Cabin pressure warning accessible as there are no doors on the front of the MAWEA. Autopilot disconnect warning Input signals are delivered from several airplane sensors and Takeoff configuration warning avionics systems. Landing configuration warning Power supply Speed brake alert Stabilizer green band indication The MAWEA consists of two internal power supplies A and B. The Ground proximity and 115 V AC Standby bus provides power to supply A and the first windshear warnings officer’s 115V AC Transfer bus provides power to supply B. Level B aural generation The power is supplied via two circuit breakers in the cockpit P7 Chime generation overhead panel. Glide slope antenna switching FOR TRAINING PURPOSES ONLY! The two power supplies are identical and provide the same dc Passenger address volume inputs to each card in the modularized avionics warning control electronics assembly (MAWEA). Passenger signs illumination Two panels, each secured by four screws, must be removed Airplane identification before gaining access to the power supplies. Signal consolidation Stall warning The power supplies are held in place by a center screw and two Altitude alert wedge clamps on the power supply sides. HAM US/O-6 SaR Sep 02, 2012 00| IMA MAWEA 744|L1|A/B1/B2 Page 40 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS MAWEA B 747 (ATA42) M11.19|M12.17|M13.20 COCKPIT OVERHEAD CB PANEL (P7): - MAWEA PWR A - MAWEA PWR B RIGHT HAND CRAWL WAY Power supply A FOR TRAINING PURPOSES ONLY! Power supply B Figure 22 Modularized Avionics Warning Electronics Assembly HAM US/O-6 SaR Sep 02, 2012 00| IMA MAWEA 744|L1|A/B1/B2 Page 41 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS MAWEA B 747 (ATA42) M11.19|M12.17|M13.20 MAWEA - Assembly General The modularized avionics warning electronics assembly (MAWEA) is a cardfile that contains cards which perform various functions. There are four types of cards in the modularized avionics warning electronics assembly (MAWEA) : Universal Logic Cards (ULCs) Aural Synthesizer Cards (ASCs) Signal Collection and Identification Cards (SCID) Digital Flight Data Acquisition Card (DFDAC) NOTE: The DFDAC is installed in the MAWEA for easy access. It does not have a warning function. The DFDAC is part of the flight recorder system. Characteristics There are 23 connectors mounted in the front of the MAWEA chassis. They allow the MAWEA to interface with other airplane systems. FOR TRAINING PURPOSES ONLY! A monitor panel on the front of the unit allows for monitoring the ARINC 429 inputs to the MAWEA and power supply voltages. An electrostatic jack is located on the lower left side of the MAWEA which allows for the use of a wrist strap when removing or installing any card. This prevents damage to the cards due to electrostatic discharges. The unit is cooled by convection. HAM US/O-6 SaR Sep 02, 2012 02| IMA MAWEA 744|L2|B1/B2 Page 42 Lufthansa Technical Training AIRCRAFT SYSTEMS EASA PART-66 M11|M12|M13 INTEGRATED MODULAR AVIONICS MAWEA B 747 (ATA42) M11.19|M12.17|M13.20 MONITOR PANEL POWER SUPPLY B (BEHIND PANEL) CARD FAULT (RED) INTERFACE FAULT (YELLOW) HANDLE ARINC MONITOR JACKS FOR TR