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PROFIBUS-PA monitoring with Bluetooth interface

1. Item Definition Attribute ID ServerClassIDList 0x0001 ServiceClass0 ProtocolDescriptionList 0x0004 Protocol0 L2CAP Protocol RFCOMM ProtocolSpecificParametrO Server Channel ServiceName Display Text name Table 3 1 SDP Service record Only Initiator may inquire and page within the execution of this profile The paging step will be skipped in Initiator when execution of this profile begins when there already exists a baseband connection between Initiator and Acceptor For additional information on Serial Port Profile see 8 p 172 193 3 3 3 Service Discovery Application Profile SDA P This profile defines the protocols and procedures that shall be used by a service discovery application on a device to locate services in other Bluetooth devices using the Bluetooth Service Discovery Protocol SDP The following roles are defined in this profile A Local device LocDev is the device that initiates the service discovery procedure This device contains the service discovery application used by a user to initiate discoveries and display the results of these discoveries A Remote Device RemDev is any device that participates in the service discovery process by responding to the service inquiries generated by a Local Device A Remote device contains a service records database The Local or Remote role assigned to a device is neither permanent nor exclusive A device could be a Local for a particular SDP transaction whil
2. For additional information on Telegram structure see 12 p 901 Start Delimiter End Delimiter Preamble Figure 2 4 Waveform of the constant parts of the Profibus telegram IEC telegram 2 3 User specifications The Profibus family consists of three compatible versions which are divided by specific application area e Profibus FMS Fieldbus Message Specification is the universal solution for communication tasks at cell level At this level programmable controllers PLCs and PCs communicate primarily with each other typical access time is approximately 100 ms At this application area a high degree of functionality is more important than fast system reaction times Baud rate is up to 500 Kbps FMS is also suitable for transfer the big amount of data Physical layer can be RS 485 or optic fiber Uses layers 1 2 and 7 layers 3 to 6 are not used 2 2 e Profibus DP Decentralized Periphery is optimized for high speed and low connection costs and has been especially designed for communication between the automation control systems PLC and distributed field devices typical access time 10 ms It can be used for data capture from periphery devices slaves 2 3 1 e Profibus PA has been specifically designed for process engineering It permits the linking of sensors and actuators to a common bus cable also in hazardous areas It enables the data communication and energy supply for devices in two wire technology
3. Client Server Application Application SDP REQUEST SDP Client SDP Server SDP RESPONSE Figure 3 10 SDP Client Server architecture 21 AI of the information about a service that is maintained by an SDP server is contained within a single service record A service record handle is a 32 bit number that uniguely identifies each service record within an SDP server each handle is unique only within each SDP server The service record consists of a list of service attributes Each service attribute describes a single characteristic of a service service attributes ServiceClassIDList ServiceID ProtocolDescriptorList ServiceName and etc 3 p 366 A service attribute consists of two components an attribute ID and an attribute value An attribute ID is a 16 bit unsigned integer that distinguishes each service attribute within a service record The attribute ID also identifies the semantics of the associated attribute value A service class definition specifies each of the attribute IDs for a service class and assigns a meaning to the attribute value associated with each attribute ID The attribute value is a variable length field whose meaning is determined by the attribute ID associated with it and by the service class of the service record in which the attribute is contained Figure 3 11 Each service is an instance of a service class The service class definition provides the definitions of all attributes contained in s
4. AM ADDR also called the MAC address A slave only accepts a packet with a matching active member address and broadcast packets the all zero AM ADDR The active member address is only valid as long as a slave is active on the channel The master assigns the address to the slave when the slave is activated A slave in park mode can be identified by its dedicated 8 bit parked member address PM ADDR When the slave is activated it is assigned an active member address but loses the parked member address The access request address AR ADDR is used by the slave in the slave initiated unpark procedure This address is assigned to the slave when it enters the park mode and is only valid as long as the slave is parked The access request address is not necessarily unique i e different parked slaves may have the same access request address Bluetooth device operates in two major states Standby default state and Connection There are seven sub states which are used to add slaves or make connections in the piconet These are page page scan inquiry inquiry scan master response slave response and inquiry response Before any connections in a piconet are created all devices are in Standby mode A connection is made by a Page message being sent if the Bluetooth device address is already known or by an Inquiry message followed by a subsequent Page message if the address is unknown The inquiry procedure enables a device to discover which devices
5. However when establishing a 12 piconet one unit will act as a master for synchronization purposes and the other s as slave s Up to seven slaves can be active in the piconet Multiple piconets with overlapping coverage areas form a scatternet Each piconet can only have a single master However slaves can participate in different piconets on a time division multiplex basis In addition a master in one piconet can be a slave in another piconet The piconets shall not be freguency synchronized Each piconet has its own hopping channel e MASTER C SLAVE O Fob A A B C Figure 3 2 Piconets with a single slave operation A a multi slave operation B and a scatternet operation C Different types of physical links can be established between master and slave s The link type defines what type of packets can be used on a particular link Two link types have been defined e Synchronous Connection Oriented SCO link used primarily for voice e Asynchronous Connection Less ACL link used primarily for packet data Different master slave pairs of the same piconet can use different link types and the link type may change arbitrarily during a session Each link type supports up to sixteen different packet types Four of these are control packets and are common for both SCO and ACL links The SCO link is a point to point symmetric link between a master and a single slave in the piconet The SCO link reserves slots at regul
6. Software Unit The Host will receive asynchronous notifications of HCI events independent of which Host Controller Transport Layer is used HCI events are used for notifying the Host when something occurs The Host and Host Controller communicate each other via the Host Controller Transport Layer i e physical bus These intermediate layers should provide the ability to transfer data without intimate knowledge of the data being transferred Several different Host transport protocols can be used of which 3 have been defined initially in the Bluetooth specification USB UART RS 232 and additional to these the CSR Cambridge Silicon Radio defined a proprietary protocol called BlueCore Serial Protocol BCSP e USB Universal Serial Bus communications standard comes from the PC industry Its architecture is a tree The Bluetooth specification always assumes the high speed 12 Mbps version USB provides a very reliable link with strong error detection and recovery The main disadvantage of USB is the implementation difficulty compared with other options e RS232 is the UART based host transport protocol requires a minimum of three communication lines Receive RX Transmit TX and Ground GND There are also 16 two optional lines RTS Ready to Send and CTS Clear to Send normally used for hardware flow control Before sending any bytes over the RS 232 link the baud rate parity type number of stop bit and protocol mode should be negotiate
7. The Bluetooth chapter describes the Bluetooth specification the main profiles used BSCP host transport protocol and the Mezoe s BlueStack protocol stack The Hardware chapter describes the main three chips and how they work and cooperate in the interface module The Software chapter describes in detail the software application running on the microcontroller MSP430 2 Profibus 2 1 Introduction Profibus PROcess Fleld BUS is a fieldbus system which is widespread all over the world AI Profibus variants are based on the ISO OSI reference model for communication networks 2 2 Profibus was standardized in the German standard DIN 19 245 The research was supported by German government in cooperation with automation manufacturers Bosh and Siemens In March 1996 this standard was embedded into the European Fieldbus standard EN 50170 Volume 2 without modifications This guarantees stability and openness for users and vendors worldwide The Profibus devices from different manufacturers can communicate without special interface adjustments Profibus is a vendor independent open fieldbus standard for a wide range of applications in a manufacturing e g automotive industries a process control e g chemical and petrochemical industries and a building automation e g air condition central heating It can be used for both high speed time critical data transmission and extensive complex communication tasks The Profibus distinguishes between the f
8. microcontroller MSP430 and the host controller Bluetooth module WML C06 The BCSP uBCSP offers the better features the error detection and recovery the better security and etc than alternative transport protocols The whole interface module should be supplied from the PROFIBUS PA bus The PROFIBUS PA is designed for the intrinsically safe operations In steady state each station on the bus consumes a maximal basic current 10 mA Therefore the low power consumption is the main requirement for the selected chips used at the interface module For this reason was also applied the microcontroller Texas Instruments MSP430 with a maximal 8 MHz s crystal This frequency fixes the number of executed instructions at the time critical sections of program The most time critical section is the interrupt service routine ISR2 for the sampling of the PROFIBUS data bits mentioned in the sub chapters 5 1 3 and 5 1 4 For this problem solution must be found the faster microcontroller with low power consumption or must be used the external power supply At this time is not such any microcontroller on the market The software was developed on the PC platform and then was ported to the microcontroller This portability was achieved by using the ANSI C language The module works as a Bluetooth master at this time That means the module must stay in the active state for all time and therefore continually consumes the energy The better way is a Bluetooth slave for thi
9. COMPLETE event is generated when the Inguiry process has completed e Listening mode DM HCI WRITE INQUIRYCAN ACTIVITY DM HCI WRITE PAGESCAN ACTIVITY DM HCI WRITE SCAN ENABLE The device is placed in listening mode by sending primitives to the device manager turning on inquiry scanning discoverable mode and page scanning connectable mode This allows the remote device to be found discoverable mode and connected connectable mode 3 2 2 e Service discovery SDC SERVICE SEARCH SDC SERVICE ATTRIBUTE The SDC SERVICE SEARCH primitive initiates a search for services on a remote device The SDC SERVICE ATTRIBUTE primitive initiates a request for attribute values e g server channel from a service record on a remote device e RFCOMM Start RFC START It initializes a logical L2CAP connection between the local device and the remote device with suggested parameters for the port speed and the maximum frame size of a RFCOMM packet The request includes the creation of a multiplexer channel MUX ID RFC START IND primitive will be received twice by the slave The first occurrence provides the opportunity of refusing the connection When the connection is admitted then the second occurrence of an RFC START IND is for configuration purposes e RFCOMM Parameter Negotiation RFC PARNEG This primitive initiates the negotiation for a RFCOMM Data Link Connection DLC The parameters such as initial credits 1f the credit based flow control is enabl
10. Firmware BlueCore01 is supplied with a Bluetooth software stack firmware that runs on its microcontroller and is resident in the external Flash memory In general there are two forms of firmware release available from CSR These firmware releases are based on splits in the Bluetooth protocol stack The usual split is at the HCI or RFCOMM level and therefore the two firmware releases available are known as either the HCI firmware or the RFCOMM firmware builds This section describes the fundamentals of an RFCOMM firmware build In the PROFIBUS Bluetooth monitoring module is used RFCOMM1 1v13 10 5 firmware RFCOMM indicates that this is an RFCOMM variant of firmware indicates that this release supports the Bluetooth Specification version 1 1 v 3 70 5 indicates that this firmware is based upon the HCI Stack1 1v13 10 firmware build and that this is the fifth 5 build based upon this firmware Two variants of this firmware are provided the first supports the BCSP Blue Core Serial Protocol transport protocol Build ID 339 or 341 and the second supports the Bluetooth UART Universal Asynchronous Receiver Transmitter protocol Build ID 340 or 342 Each variant is available in versions that support both 56 and 128 bit encryption Build IDs and identifier strings can be checked using the PSTool utility or BlueFlash utility available from CSR RFCOMM bandwidth is limited to approximately 360 Kbps The default Persistent Store settings are optimize
11. RFCOMM SDP L2CAP DM HCI Link Manager Link Controller BASEBAND and RF HW Wholly Embedded single processor architecture Figure 3 16 BlueStack Integration Service Discovery Client SDC Interface provides service searching functions for the host application The parameters for these primitives are listed in the sdc prim h file The parameters include pointers to data describing the search patterns and attribute lists for services being searched for Both search patterns and attribute lists are formatted as the data element sequences as described in 8 p 349 There are seven basic primitives associated with this interface more about these primitives in 9 p 111 32 Service Discovery Server SDS Interface allows an application to register and maintain the database of services provided by the local device The parameters for these primitives are listed in the sds prim h file There are three primitives associated with this interface more about these primitives in 9 p 111 132 For message passing between layers of the protocol stack a service primitive model has been adopted Figure 3 17 If layer N 1 wants to send data to its peer it presents this data along with a service reguest REO to layer N reguesting the service that sends the data On arrival of the protocol message the peer layer N sends an indication IND to the peer layer N 1 In the most complete realization of the mode
12. RS 485 transmission technology sss 4 Basic characteristics of IEC 1158 2 transmission technology 4 Numeric values of constant parts of the Profibus telegram IEC telegram 6 Physical Profibus PA layer venidas 8 SDP Service TOCORG 3 ties sudo A duas do beu de ada stillet em ss 25 Be PohlaneIsallooattone O ee E 27 tU encoding s eee e Seco dui eiie dd o ataca opos amare oo e Sao aed 42 TMG ASCO GPUS rs ui edit et emt tas dvi tente oat sio 43 1 Introduction The main goal of this diploma thesis is the implementation of an interface between the industrial communication technology PROFIBUS PA and the office radio technology Bluetooth This interface could be used for the remote monitoring of industrial devices This diploma thesis was created at the Institut f r Automation und Kommunikation e V ifak Magdeburg Germany This institute executes the research based in the following fields automation communications and sensors The ifak has the certification laboratory for PROFIBUS PA devices The Bluetooth radio technology presents a cheap and efficient solution for short range wireless data transfer On the other hand the PROFIBUS PA is a widespread data transfer standard in the process automation The conjunction of these two technologies presents a new and easier option for the industrial data transfer The advantages of this solution are the connection and the devices
13. Table 5 1 Logic 0 is indicated by a 0 to 1 transition rising edge at the center of the bit and logic 1 is indicated by a 1 to 0 transition falling edge at the center of the bit Note that the signal transitions do not always occur at the bit boundaries the division between one bit and another but that there is always a transition in the middle of each bit Original Data Sending Data Locic 0 LOW 0 to 1 upward transition at bit centre Logic 1 HI 1 to 0 downward transition at bit centre Table 5 1 Manchester encoding There are two bits of Manchester encoded data for each bit of original data The penalty for doing this is Manchester encoded data consumes more bandwidth than original data in NRZ code Zero DC component of serial bit stream and simple error detection are the main advantages of using Manchester encoding The example of Manchester Encoding is shown at Figure 5 3 CLOCK ORIGINAL DATA MANCHEST ER DATA Figure 5 3 Example of the Manchester encoded data Given that a 0 encodes to 01 and 1 encodes to 10 it follows that 00 and 11 are illegal sequences These codes are used to the data error check The illegal code is used as a unique start stop pattern to identify the boundaries of data frame as well 5 1 1 2 Decoding This chapter only describes the decoding technology which is used for decoding from the Manchester code 5 1 1 1 2 to the NRZ code 5 1 1 1 1 The same way dir
14. UK http www mezoe com 10 SIM I User Technical Description version 1 1 Revision 05 1997 Siemens AG Germany http www siemens com 11 SIM I Extension to the User Description version 1 1 Revision 06 2000 Siemens AG Germany http www siemens com 12 Profibus Specification Revision 03 1998 Profibus International Karlsruhe Germany http www profibus com 13 Profibus PA Profile version 3 0 Revision 10 1999 Profibus Nutzerorganisation e V Karlsruhe Germany http www profibus com 14 Technical information Profibus PA Revision 12 199 Samson Frankfurt Germany http www samson de 15 MITSUMI Bluetooth module WML C06 Mitsumi http www mitsumi com 16 BlueCore01 Embedded Solutions AN062 Revision 05 2001 Cambridge silicon radio CSR Cambridge UK http www csr com 17 BlueCore01 Single Chip Bluetooth System Revision 2000 Cambridge silicon radio CSR Cambridge UK http www csr com 18 Using the BlueStack API over BCSP AN 002 Revision 2001 Mezoe Cambridge UK http www mezoe com 54 19 Xap2 Asic processor Cambridge Consultants Ltd Cambridge UK http www camcon co uk 20 Persistent Store Key Setting AN102 Revision 09 2001 Cambridge silicon radio CSR Cambridge UK http www csr com 21 BlueSuite v 1 17 Release note bcore srn 016Pa Revision 10 2002 Cambridge silicon radio CSR Cambridge UK http www csr com 22 RFCOMM I 1v1
15. bit InputRegister P1IN read the sample value from PORT InputRegister InputRegister gt gt 1 shift to the first position of register InputRegister amp 0x01 elimination of the pin P1 1 RxS RES gVar ManDecDataWord InputRegister RES gVar countManDecSampleBitst count sample bits if RES_gVar countManDecSampleBits gt RES MANDEC DATALENMAX RES gVar ManDecDataWord RES MANDEC ENDDEL I RES_gVar ManDecDataWord amp OxFF 0x0 amp amp RES gVar countManDecSampleBits gt OxF RES_gVar ManDecDataWord 0 FullProfibusFrame TRUE CCTL1 amp CCIE hnterrupt disable in the compare mode TACTL amp MC0 amp MC1 stop timer TACTL TACLR clear timer CCTLO amp CCIFG reset interrupt CCTLO CCIE hnterrupt enable in the capture mode restart synchronization TACTL MC_2 start timer in the continuous mode j else If RES gVar countNRZBits gt 0x10 DataBuffer WriteDataIndex RES gVar characterBuffer WriteDatalndex RES_gVar countNRZBits 1 RES_gVar ManDecToggleBit RES gVar ManDecToggleBit j else RES gVar ManDecToggleBit RES gVar ManDecToggleBit If RES gVar ManDecToggleBit FALSE 1 If RES gVar ManDecDataWord amp 0x0003 2 RES gVar characterBuffer 0x1 10 Manchester 1 NRZ 01 Manchester O NRZ RES gVar characterBuffer RES gVar characterBuffer 1 j if RES_gVar ManDecDataWord RES MANDEC STARTDEL amp amp RES
16. device operating in the 2 4 GHz ISM Industrial Scientific Medicine band The Bluetooth radio accomplishes spectrum spreading by freguency hopping in 79 hops 79 MHz range displaced by 1 MHz starting at 2402 MHz and finishing at 2480 MHz RF channels f 2402 k MHz k 0 78 In some countries Spain France Japan this frequency band range is temporarily reduced and a 23 hops 23 MHz range system is used It should be noted that products implementing the reduced frequency band would not work with products implementing the full band The maximum frequency hopping rate is 1600 hops s it is equal to slot length of 625 us It is enable high performance in noisy radio environments The Bluetooth radio module uses GFSK Gaussian Frequency Shift Keying modulation characteristic where a binary one is represented by a positive frequency deviation and a binary Zero by a negative frequency deviation Bluetooth radio modules avoid interference from other signals by hopping to a new frequency after transmitting or receiving a packet The Bluetooth specification has defined three power levels e Power Class 1 is designed for long range devices 100m with a maximal output power of 100 mW 20 dBm e Power Class 2 is designed for ordinary range devices 10m with a maximal output power of 2 5 mW 4 dBm e Power Class 3 is designed for short range devices 10cm with a maximal output power of 1 mW 0 dBm The Bluetooth radio interfac
17. etc which are not shown at this figure Profibus PA Bluetooth Interface Vous SIEMENS IxE TXS TI gt SIM 1 MSP430F148 Vsus RxA RxS a U T Hand held computer m pmi E MITSUMI lt Bluetooth WML C06 m nn Laptop computer Figure 4 1 Hardware conception of PROFIBUS Bluetooth monitoring module 4 1 Siemens SIM 1 For simple I O devices a practical solution is implementation with single ASICs Application Specific Integrated Circuit chips All protocol functions are already integrated in the ASIC No addition microprocessor or software is required In the implementation of bus powered field device with IEC 1158 2 interface particular attention must be paid to low power consumption As a rule only a supply current less than 10 mA is available for these devices To be able to meet these requirements special chips SIM 1 are available from Siemens SIM 1 Siemens IEC MAU enables the construction of a Fieldbus Medium Attachment Unit MAU for 31 25 Kbps according to IEC 1158 2 standard 2 2 1 with only a few external components This chip can take the required operating energy from the IEC 1158 2 bus connection or from external power supply and make it available as a supply voltage for the other electronic components of the PA device 34 The SIMI contains a standard signal interface TxS Transmit S
18. file contains the type definitions and prototypes for uBCSP engine e ubcspcfg h configuration file which allows to set up these features use CRC show the link establishment states show packet errors From the users perspective the interface to the uBCSP engine has been simplified down to four main functions to make up the application programming interface API These are e ubcsp initialize initializes the uBCSP engine e ubcsp send packet sets up a packet to be sent from upper layer down e ubcsp receive packet sets up a packet structure to be used for receiving packets from the lower layer up This function should also be called only after the ubcsp initialize function so that the link establishment packets can be processed 29 e ubcsp poll allows the upper layer stack to control the execution of the uBCSP engine The get uart and put uart functions are system specific and will need to be modified with respect to the system specific UART For additional information on uBCSP see 4 3 5 Bluetooth Protocol Stack Mezoe s BlueStack BlueStack is a software implementation in C of the Bluetooth protocol stack as shown in Figure 3 15 BlueStack introduces the Device Manager DM This provides a number of stack management functions such as security management and allows access to the HCI command and event interface The terms Top and Bottom are used to distinguish between the HCI on th
19. for detecting errors The BCSP is used to control and format information that flows between a Bluetooth Host and a Bluetooth Host Controller An instance of the BCSP runs on both the Host and the Host Controller Higher layers of the stack can be built upon the two datagram services Figure 3 13 e One bi directional reliable datagram stream with 16 channels messages are repeatedly sent until the peer acknowledges reception It is possible to use windowing mechanism sequence and acknowledge numbers e One bi directional unreliable datagram stream with 16 channels messages are sent to the peer once This type of message is naturally suited for SCO links Datagram passed through BCSP carry a 4 bit protocol identifier so this effectively gives 16 channels of each type the channel identifier zero must not be used by code above BCSP thus code above BCSP sees 15 channels of each type Protocol identifier is used to multiplex 16 parallel bi directional message channels across a single UART link The whole channels allocation is shown in Table 3 2 26 HOST HOST CONTROLLER Rest of Host system Rest of Host Controller system BCSP Channels 15 15 E OS on O f 15 15 BCSP Stack BCSP Stack UART UART UART Link Figure 3 13 BCSP Context The primary data flows are e Messages sent down into the BCSP stack These normally include HCI Com
20. gVar ManDecPDU FALSE WriteDatalndex 0 RES gVar ManDecPDU TRUE RES gVar ManDecToggleBit FALSE clear status bit RES gVar countNRZBits 1 RES gVar characterBuffer 0 RES gVar ManDecDataWord 0 j RES gVar ManDecDataWord RES gVar ManDecDataWord lt lt 1 shift data word left RES gVar countNRZBits P20UT amp 0x04 testing point toggle bit j 53 Document References 1 BCSP User guide AN110 Revison 11 2001 Cambridge silicon radio CSR Cambridge UK http www csr com 2 BlueCore serial protocol BCSP bcore sp 012Pa Revision 01 2003 Cambridge silicon radio CSR Cambridge UK http www csr com 3 Specification of the Bluetooth System Core Revision 02 2001 Bluetooth SIG http www bluetooth com 4 uBCSP user guide bcor ug 001Pa Revision 03 2002 Cambridge silicon radio CSR Cambridge UK http www csr com 5 ABCSP overview AN111 Revision 11 2001 Cambridge silicon radio CSR Cambridge UK http www csr com 6 YABCSP Overview bcore an 012Pa Revision 01 2003 Cambridge silicon radio CSR Cambridge UK http www csr com 7 BCSP Link establishment Protocol bcore sp 008Pa Revision 01 2003 Cambridge silicon radio CSR Cambridge UK http www csr com 8 Specification of the Bluetooth System Profiles Revision 02 2001 Bluetooth SIG http www bluetooth com 9 BlueStack user manual Revision 2001 Mezoe Cambridge
21. two Bluetooth devices 23 The purpose of the channel establishment procedure is to establish a Bluetooth channel a logical link between two Bluetooth devices Channel establishment starts after link establishment is completed when the initiator sends a channel establishment reguest The purpose of the connection establishment procedure is to establish a connection between applications on two Bluetooth devices Connection establishment starts after channel establishment is completed when the initiator sends a connection establishment reguest initialization of RFCOMM and establishment of DLC in the case of a Serial Port Profile For additional information on Generic Access Profile see 10 p 13 62 3 3 2 Serial Port Profile SPP The Serial Port Profile defines the reguirements for Bluetooth devices necessary for setting up an emulated serial cable connections using RFCOMM between two peer devices The scenario covered by this profile is the setting up virtual serial ports on two devices and connecting these with Bluetooth to emulate a serial cable between the two devices Any legacy application may be run on either device using the virtual serial port as if there were a real serial cable connecting the two devices with RS 232 control signaling Only one connection at a time is dealt with in this profile only point to point configurations However multiple executions of this profile should be able to run concurrently in the same dev
22. type of medium including length and topology the line interface the number of stations and the transmission speed the electrical and the mechanical characteristics modulation coding 2 2 1 e Data link layer Qe layer is responsible for the reliable data transfer via physical medium telegram structure address and control of data flow In Profibus layer 2 is called Fieldbus Data Link FDL It splits in two sub layer Medium Access Control MAC access on the common medium Token Passing Master Slave and LLC Logical Link Control telegram structure and control of data flow 2 2 2 e Application layer 7 layer presents the services for application user processes Application layer is only used in the FMS version of Profibus 2 Application programs A FMS DP PA o a FMS Profile DP Profile PA Profile User DP extension DP basic functions Fieldbus Message Application 7 Specification FMS 3 6 Not used Data Link 2 Fieldbus Data Link FDL TEC Interface Physical 1 RS 485 Fiber Optical IEC 1158 2 EN 50 170 PROFIBUS Profiles Figure 2 1 Layered structure of Profibus protocol architecture For additional information on ISO OSI reference model see 12 2 2 1 Physical layer The application area of a fieldbus system is largel
23. 3 10 5 Release note bc01 srn 030Pa Revision 05 2002 Cambridge silicon radio CSR Cambridge UK http www csr com 23 MSP430x1xx Family User s Guide SLAU049B Revision 2002 Texas Instruments Texas USA http www ti com 24 MSP430x14x SLAS272C Revision 02 2001 Texas Instruments Texas USA http www ti com 25 RFCOMM Packing Rules bcore an 004Pa Revision 08 2002 Cambridge silicon radio CSR Cambridge UK http www csr com Internet addresses Compilers e MSPGCC http www mikrocontroller net e AR Embedded Workbench for MSP430 http www iar com 55
24. Bluetooth device supports multiple emulated serial ports and the connections are allowed to 19 have endpoints in different Bluetooth devices then the RFCOMM entity must be able to run multiple multiplexer sessions Note that each multiplexer session is using its own L2CAP channel ID CID Figure 3 8 Master Application Emulated serial ports Emulated serial ports o EE 3 1 MD 30 er Po KO 60 G6 6 Lop D 0 RFCOMM session 1 RFCOMM session 2 D 1 CID 1 CID 2 L2CAP Baseband amp Radio lt RADIQA ISSN a Baseband amp Radio Baseband amp Radio L2CAP L2CAP RFCOMM p D 0 RFCOMM 1 2 o o o 30 1 2 o o o 30 3 _G 61 2 4 60 Emulated serial ports Emulated serial ports Applicati rac Slave 1 lt Slave 2 y Figure 3 8 Multiple emulation serial ports There is logically one multiplexer associated between two Bluetooth devices The MUX_ID is the identifier used locally between RFCOMM and the application above it It is assigned by RFCOMM usually as a result of the RFC Start Reg primitive 3 5 Each multiplexer instance supports one or more server channels The relationship
25. CZECH TECHNICAL UNIVERSITY IN PRAGUE Faculty of Electrical Engineering Department of Control Engineering Institut fur Automation und Kommunikation e V Magdeburg Germany PROFIBUS PA monitoring with Bluetooth interface 2003 Student Petr JUR K Supervisor Ing Ond ej Dolej ESK VYSOK U EN TECHNICK V PRAZE Fakulta elektrotechnick Katedra dic techniky Institut fur Automation und Kommunikation e V Magdeburg Germany Monitorov n sb rnice PROFIBUS PA p es Bluetooth rozhran 2003 Diplomant Petr JUR K Vedouc pr ce Ing Ond ej Dolej Prohl en Prohla uji e jsem svou diplomovou pr ci vypracoval samostatn a pou il jsem pouze podklady literaturu projekty SW atd uveden v p ilo en m seznamu Nem m z va n d vod proti u it tohoto koln ho d la ve smyslu 60 Z kona 121 2000 Sb o pr vu autorsk m o pr vech souvisej c ch s pr vem autorsk m a o zm n n kter ch z kon autorsk z kon V Praze dne 22 05 2003 GG GG cc fenes Petr JURCIK Annotation Data from the PROFIBUS PA fieldbus is transmitted via the Bluetooth radio interface to the Bluetooth suitable devices such as PCs PDA and etc There are used the following hardware components at the developed interface module ASIC chip Siemens SIM 1 for power supply from the PROFIBUS PA bus and for a signal decoding microcontroller Texas Instruments MSP430F148 for download and run the appropriate s
26. EE 802 11b Wi Fi is an open standard technology that enables wireless connectivity between laptops and local area networks Today s Wi Fi products which transmit in the unlicensed spectrum at 2 5 GHz are capable of speeds of up to 11 Mbps e HomeRF version 2 0 also uses the same frequency band 2 4 GHz but does not interfere with Bluetooth technologies It uses centralized concept a central unit in contrast to Bluetooth ad hoc This standard includes support for advanced networking features like security frequency hopping network password 128 bit encryption interference dodging and quality of service HomeRF 2 0 runs at 10 Mbps same as standard wired Ethernet The HomeRF 2 0 chipset is tiny and uses very little power 3 3 V 120 mA receive 250 mA transmit 3 mA standby The HomeRF specification is not free 3 2 Specification The Specification describes how the technology works i e the Bluetooth protocol architecture The actual version of Bluetooth specification is version 1 1 The layered model of Bluetooth protocol stack is shown in the Figure 3 1 and briefly described in the next sub chapters RFCOMM SDP L2CAP HCI Link Manager Baseband Radio Figure 3 1 Bluetooth Protocol Stack as Specified by the Bluetooth SIG 11 3 2 1 Radio specification The Bluetooth Radio layer is the lowest defined layer of the Bluetooth specification It defines the reguirements of the Bluetooth transceiver
27. I described the used communication technologies The Bluetooth technology was described more detailed than PROFIBUS PA because it is new in the industry communication The developed module can be split up into the two independent parts The first part is made up the PROFIBUS PA interface with the ASIC chip Siemens SIM 1 The second part is made up the Bluetooth radio interface with the Bluetooth module Mitsumi WML C06 The common part for these two transmitted technologies and also the controlling unit of the whole interface module is the microcontroller Texas Instruments MSP430F148 The same division can be applied at the software application that runs on the microcontroller The one sub program receives the PROFIBUS data from the output of the SIM 1 chip decodes it from Manchester code to the NRZ code and this decoded data saves in the common data buffer The other sub program reads the data from the common data buffer and sends it via the UART interface to the Bluetooth module The Bluetooth module transmits this data via the Bluetooth radio interface to the Bluetooth suitable device such as PCs PDA and etc The Mezoe s BlueStack was applied as a Bluetooth protocol stack in the embedded two processors architecture This protocol stack presents the most efficient solution for the Bluetooth module based on the CSR s Cambridge Silicon Radio BlueCore01 chip The BCSP uBCSP is a host transport protocol runs over the physical UART link between the host
28. PROFIBUS PA data 5 1 1 1 2 with using the capture compare unit of a MSP430F148 microcontroller 4 2 S 1 1 Coding Uniquely assignment between the elements of one set and the elements of another set is called coding At the transmission end of link is used encoding procedure and at the receiving end of link is used decoding procedure of transfer data Uncoded data signal is not suitable for direct transfer via data channel e g includes DC component There is the next problem with synchronization between the transmission and receiving end of transfer link at the uncoded signal The encoding is the result for addition the synchronization and rejection of DC component of signal 40 5 1 1 1 Encoding In the next subchapters are described these two encoding technology e NRZ 5 1 1 1 e Manchester 5 1 1 1 2 5 1 1 1 1 NRZ Non Return to Zero Non Return to Zero NRZ encoding is commonly used in slow speed communications interfaces for both synchronous and asynchronous transmission The NRZ signal belongs to the polar signals A polar signal may have a two state non return to zero NRZ binary coding scheme A polar signal is usually symmetrical with respect to zero amplitude 1 e the absolute values of the positive and negative signal states are nominally egual NRZ signal is without spaces and without zero polarity only with positive and negative polarity The advantage of NRZ signal is rejection of DC component A problem aris
29. Profile SDAP eee eee 25 3 4 BCSP BlueCore Serial Protocol mmooommsss 26 3 41 OCA A a betae 26 3 42 Porting BOSP i osada ag de 28 342 ABCSP and YABCSP is 28 Be RI o 1 B1 S PoE Oo er ME DO E AA 29 3 5 Bluetooth Protocol Stack Mezoe s BlueStack eere eerte eene 30 4 HARDWARE o oo o mp E EE EE LE 34 A1 Siemens SIM Liria a di A 34 4 2 Texas Instruments MSP430F148 eee e eee eese eee eese eese sensit etes sees ese so sse eee 35 4 2 1 TIME 200 SI IAS EIA E PO HIS du 35 4 2 2 A tipa tpud 36 4 3 Mitsumi s Bluetooth module WML C06 ceres ceres eee en eene netten seta se tnnn 36 4 3 1 CSRs BlueCore lI chp scii ed oo Net eo deua acd tu untae ms 37 4 3 2 RECO MVE Firmware nd a Les eret O out ars aa owes 37 5 SES gus flle tem 39 5 1 Software interface Profibus Microcontroller ecce eee ee ee eren eere nne 40 5 1 1 COGO oso costes epi RS dn sk Pol ka Sead sada odd dou taser eden best ten 40 Dy Lal o a Ns seine Rion mane OA a A AA 41 5 1 1 1 1 NRZ Non Return to LEO ii vd aii 41 SA 2 Manchester EAS AS 41 klaro 42 5 2 Intetr pt Sepvice TONES A or tbe d ER REG adda ewes 43 5 1 3 Time calculation e bu oo bm E E o 44 5 1 4 Interrupt service routine ISR2 Implementation eee 45 5 2 Software interface Microcontroller Bluetooth e eeeeee eee e eene n nne 46 5 2 1 Bl eStack concepte ooi e
30. R REO gt DM AM REGISTER REO DM AM REGISTER CFM DM AM REGISTER CEM gt DM HCI READ BD ADDR gt DM HCI WRITE INQUIRYSCAN ACTIVITY DM HCI READ BD ADDR COMPLETE DUCI WEITE_INQUIRYSCAN ACTIVINY COMPLETE a DM HCI WRITE PAGESCAN ACTIVITY DM HCI WRITE PAGESCAN ACTIVITY COMPLETE y DM HCI WRITE SCAN ENABLE DM HCI INOUIRY gt DM HCI WRITE SCAN ENABLE COMPLETE y HS ORAVA Je RR Sao dob DM HCI RESULT hn DES DM HCI INQUIRY COMPLETE SDC SERVICE SEARCH REQ gt Rie E EAEE SDC SERVICE SEARCH CFM SDC SERVICE ATTRIBUTE REQ gt EOI as a ae NI SDC SERVICE ATTRIBUTE CFM A RFC START REO gt RFC START IND gt RFC START RES RFC START IND gt RFC START RES RFC START CFM AAA RFC PARNEG REO gt a RFC PARNEG IND gt RFC PARNEG RES RFC PARNEG CFM AA RFC ESTABLISH REO bl R RFC ESTABLISH IND gt RFC ESTABLISH RES RFC ESTABLISH CFM ov RFC DATAWRITE REQ gt diria d RFC DATA IND gt RFC DATAWRITE CFM Mf n nn RFC RELEASE REQ gt R RFC CLOSE REQ gt RFC RELEASE IND gt AAA EEN RFC CLOSE IND gt Figure 5 8 Message sequence chart for data link set up between two BlueCore devices 50 Listening Mode 6 Conclusion In this diploma thesis I suggested and realized the software for the PROFIBUS PA and Bluetooth interface module In the theoretical parts of this document
31. a four byte header and a payload that can contain 0 up to 4095 bytes The Packet structure is described in detail in 1 Before any transmission begins a Link Establishment procedure enforces synchronization without hardware flow control lines Link establishment is based on two basic messages SYNC SYNC RESPONSE and CONF CONF RESPONSE These messages are sent unreliably The purpose of the link establishment is to know if the other device is ready to communicate and to determine in which state it is 1 7 BlueCore chips Bluetooth chips produced by CSR contain dedicated hardware to improve performance when using BCSP In addition BlueCore chips have hardware support for two methods of reducing power consumption when the chip is idle Shallow Sleep current consumption to 2 mA and Deep Sleep current consumption to 100 LA For additional information on BCSP see 1 3 4 2 Porting BCSP The generic BCSP host stack consumes too much RAM Random Access Memory for use in small embedded applications Hence CSR provides other BCSP implementations optimized for different applications uBCSP micro BCSP ABCSP Another BCSP and YABCSP Yet Another BCSP The all BCSP stacks are provided with ANSI C source codes With firmware RFCOMM1 1v13 10 5 Build 339 BCSP interface on the Host controller side it can be used all implementations of BCSP generic BCSP ABCSP YBCSP uBCSP on the Host side 3 4 2 1 ABCSP and YABCSP ABCSP Another Bl
32. a master master communication relationship that is supported only the Profibus FMS During operation defective or switched off active stations are automatically removed from the ring and new stations are added to the ring 13 2 2 2 2 Logical link control This sublayer is responsible for a telegram structure Profibus uses more types of telegrams for optimal utilization transfer channel The Fieldbus Data Link FDL defines the following telegrams e telegrams without data field 6 control bytes SDL 10h e telegrams with one data field of fixed length 8 data and 6 control bytes SDL A2h e telegrams with a variable data field 0 to 244 data bytes and 9 to 11 control bytes SDL 68h e brief acknowledgement 1 byte e token telegram for bus access control 3 bytes SDL DCh In Figure 2 3 the top part illustrates the structure of a FDL telegram with a variable data field length While the bytes of the FDL telegram are transmitted asynchronously in the form of UART characters the transmission on the IEC segments is bit synchronous Here the FDL telegram is additionally supplied with the preamble and the start and end delimiters Each FDL frame on Data Link Layer consists of a Start Delimiter Data Link SDL an Information Field and a Frame check sequence FCS The Information Field is divided into an Address Field and a Control Field Additionally a Data Unit may exist 14 On the Physical layer 2 2 1 the start of all IEC tel
33. according to the international IEC 1158 2 standard 2 3 2 2 3 1 Profibus DP The Profibus DP is designed for high speed data exchange at the field level The central control devices such as PLC PC communicate through a fast serial connection with distributed field devices such as I O drives valves and etc Data exchange with these distributed devices is mainly cyclic Each field device exchanges its input and output data with the automation device DPMI within a given cycle time The bus cycle time must be shorter than the program cycle time of the central automation system PLC Usually the bus cycle time is approximately 10 ms and the program cycle time is approximately 40 ms In addition DP also offers extended acyclic communication services for the parameterization operation monitoring and alarm handling of intelligent field devices These diagnostic messages are transmitted over the bus and collected at the master DPM2 The transmission technology can be RS 485 2 2 1 or fiber optic with baud rate from 9 6 Kbps up to 12 Mbps DP transmission time depends on the number of stations and the transmission speed DP permits mono master one master is active on the bus or multi master several masters are connected to one bus These master represent either independent subsystems each consisting of one class 1 master and its assigned slaves or additional diagnostic devices class 2 masters systems A maximum 126 devices masters or s
34. ar intervals and can therefore be considered as a circuit switched connection The ACL link is a point to multipoint packet oriented link between the master and all the slaves participating on the piconet and supports both symmetric and asymmetric traffic In the slots not reserved for the SCO link s the master can establish an ACL link on a per slot basis to any slave including the slave s already engaged in an SCO link packet switched type Up to three simultaneous synchronous voice channels or a channel which simultaneously supports asynchronous data and synchronous voice can be used in Bluetooth Each voice channel supports a 64 Kbps synchronous voice channel in each direction The asynchronous channel can support maximal 723 2 Kbps asymmetric and still up to 57 6 Kbps in the return direction or 433 9 Kbps symmetric in both directions Bluetooth has five logical channels which can be used to transfer different types of information These channels are carried by SCO or and ACL links Four possible types of addresses can be assigned to Bluetooth units Each Bluetooth transceiver is allocated a unique 48 bit Bluetooth device address BD ADDR This 48 bit address is divided into three fields 13 e LAP field lower address part consisting of 24 bit e UAP field upper address part consisting of 8 bit e NAP field non significant address part consisting of 16 bit Each slave active in a piconet is assigned a 3 bit active member address
35. are in range and determine the addresses and clocks for these devices With the paging procedure an actual connection can be established The Bluetooth device may leave the Standby state to scan for page or inquiry messages or to page or inquiry itself When responding to a page message the unit enters the Connection state as a slave When carrying out a successful page attempt the unit will enter the Connection state as a master Figure 3 3 The Bluetooth units can be in several modes of operation during the Connection state e Inthe Active mode the Bluetooth unit actively participates on the channel The master schedules the transmission based on traffic demands to and from the different slaves Active slaves listen in the master to slave slots for packets e In the Sniff mode a slave device listens to the piconet at reduced rate it listens only every M slots The sniff interval is programmable and depends on the application e Inthe Park mode a device is still synchronized to the piconet but does not participate in the traffic have no active member address Parked devices only occasionally listen to the traffic of the master to re synchronize page messages and check on broadcast messages Instead of active member address AM ADDR it receives two new addresses park member address PM ADDR and access request address AR ADDR e Hold mode is a power saving mode that can be used for connected units in a piconet if no data needs to
36. ations masters or slaves can be linked up in one segment If there are more than 32 stations repeaters must be used to link up the individual bus segments An active bus terminator at the start and end of each segment terminates the bus RS 485 uses asynchronous transmission with NRZ coding one character has 11 bits 1 start bit 8 data bits 1 even parity bit 1 stop bit 13 Medium shielded twisted pair cable Number of station 32 stations in each segment without repeater Transmission 9 6 Kbps to 12 Mbps asynchronous NRZ coding Topology linear bus Remote powering power supply using a separate cable Table 2 1 Basic characteristics of RS 485 transmission technology e IEC 1158 2 low speed H1 is a synchronous transmission with Manchester coding 5 1 1 1 2 without mean values in accordance with IEC 1158 2 standard Constant baud rate of 31 25 Kbps is used in process automation IEC 1158 2 applies the specifications of the FISCO Fieldbus Intrinsically Safe Concept model for intrinsically safe operation In steady state each station consumes a maximal basic current 10 mA With bus powering this current serves the power supply to the field devices The basic current is modulated by the sending device in the range of 9 mA Each segment has only one source of power the power supply unit For an optimum electromagnetic compatibility EMC the bus lines must be shielded The bus line must be equipped with a
37. be transmitted The master unit can put slave units into HOLD mode where only an internal timer is running Any device can wake up the link again with an average latency of 4 seconds During the hold mode the slave unit keeps its active member address AM ADDR 14 STANDBY INOUIRY PAGE unknown address known address DATA TRANSFER CONNECTION Low Power Modes Figure 3 3 Operating states in the Bluetooth system For additional information on Baseband Specification see 3 p 33 181 3 2 3 Link Manager Protocol LMP The Link Manager Protocol LMP is used by the Link Managers for link set up security and control The messages are filtered out and interpreted by Link Manager on the receiving side and are not propagated to higher layers To perform its service provider role the LM uses the services of the underlying Link Controller LC Link Manager messages have higher priority than the user data At the link layer the security is maintained by authentication the process of verifying who is at the other end of the link of the peers and encryption of the information For this basic security it is needed a public address which is unique for each device Bluetooth device address two secret keys authentication keys and encryption key and a random number generator After authentication encryption may be used to communicate When two devices do not have a common link key an initialization key Kin i
38. between the server channel and the multiplexer is best explained by way of the example illustrated in Figure 3 9 In this example there is a master device communicating with two slaves The master device has two server channels that correspond to specific applications There is a one to one correspondence between a multiplexer instance identified by a MUX ID and a slave Therefore either slave can access the services that are associated with the server channels 1 and 2 on the master the differentiator being the MUX ID MUX I is associated with slave 1 and MUX 2 with slave 2 20 i Master iu cd Slave 1 A Slave 2 Server Server Server Server Server Server channel 1 channel 2 channel 1 channel 2 channel 1 channel 2 MUX 1 MUX 2 MUX 1 MUX 2 ML Figure 3 9 Multiplexer and Service Channels Relationship Example The device opening up the first emulated serial port connection between two devices is responsible for first establishing the multiplexer control channel The device closing the last connection DLC on a particular session is responsible for closing the multiplexer by closing the corresponding L2CAP channel Wired ports commonly use flow control such as RTS CTS to control communications On the other hand the flow control between RFCOMM and the lower layer L2CAP depends on the service interface sup
39. cal block contains general device information such as device name manufacture version and serial number Transducer block contains application specific data such as correction and calibration parameters and make the connection with actuators or measuring sensors Function block provides measured values which come from transducer block to the connected bus or vice versa and checks the limit values For additional information on Profibus PA see 13 or 14 3 Bluetooth 3 1 General Description 3 1 1 Introduction The Bluetooth is an open low cost low power radio based communications standard for short range point to multipoint voice and data wireless transfer Bluetooth can transmit through solid non metal objects Its nominal link range is from 10 cm to 10 meters but can be extended to 100 meters by increasing the transmit power It is based on short range radio links and facilitates ad hoc connections for stationary and mobile communication environments It replaces the many proprietary cables that connect one device to another with one universal short range radio link Where did the Bluetooth name originally come from It named after a Danish Viking and King Harald Bl tand translated as Bluetooth in English who lived in the latter part of the 10th century Harald Bl tand united and controlled Denmark and Norway hence the inspiration on the name uniting devices through Bluetooth Ericsson Mobile Communication started the work
40. ccess to BlueStack RFCOMM layer primitives e rfcomm h Header file contains dedicated RFCOMM layer specific definitions and prototypes for rfcomm c source file e rfcomm p h Header file defines RFCOMM layer primitive definitions and messages e sdp c C Source file contains the access to BlueStack service discovery primitives e sdp h Header file contains dedicated service discovery specific definitions and prototypes for sdp c source file e sde prim h Header file defines SDP layer primitive definitions and messages e resl c C Source file contains PROFIBUS interrupt service routines and hardware initialization functions for whole PROFIBUS Bluetooth monitoring module e resl h Header file contains the type definitions and prototypes for res c source file e ubcsp c C Source file for the uBCSP engine e ubcsp h Header file contains the type definitions and prototypes for uBCSP engine e ubcspcfg h Header file for configuring the uBCSP engine 39 dm c r comm c sdp c dm h rfcomm h sdp h dm prim h rfcomm p h sdc prim h ubcsp c ubcsp h ubespcfg h Hardware dependent file Figure 5 1 The hierarchical structure of program files These files runs on a MSP430F148 microcontroller with an 8 MHz oscillator Thus the instruction cycle of the processor is 125 ns 5 1 Software interface Profibus Microcontroller This chapter describes a method for decoding a Manchester encoded bit stream the
41. d between the Host Controller and the Host e UART Universal Asynchronous Receive Transmit is the simplest of the Bluetooth standard host transport protocols It is defined to operate over an RS 232 link with no parity Hardware flow control is required The huge disadvantage with UART is its poor error detection and the absence of any useful error recovery strategy When something does go wrong the only way to recover is to reset the Bluetooth device breaking all Bluetooth links It may be cheap and easy to implement but it is not robust e BCSP BlueCore Serial Protocol overcomes the number of limitations posed by the USB RS 232 and UART BCSP is designed to simplify the RS 232 protocol that has a major impact on RAM It is described in the special section 3 4 The HCI provides a uniform command method of accessing the Bluetooth hardware capabilities The results of commands will be reported back to the Host in the form of the events The HCI Command Packet is used to send commands to the Host Controller from the Host The format of the HCI Command Packet is shown in Figure 3 5 Each command is assigned a 2 byte Opcode used to uniquely identify different types of commands 31 0 16 OpCode Parameter Total Petro OCF OGF Lenght Parameter 1 Parameter Parameter N 1 Parameter N Figure 3 5 HCI Command Packet The HCI Event Packet is used by the Host Controller to notify the Host when events occu
42. d for point to point applications such as headset or cable replacement In this release the on chip RFCOMM buffer size is approximately 750 bytes For frame sizes of less than 370 bytes it is possible to fit two or more frames in the buffer simultaneously The Host can therefore transfer a packet over BCSP 37 while BlueCore01 transmits a packet over the radio At frame sizes greater than 370 bytes it is only possible to fit a single frame into the buffer and the host must wait for the frame to be transmitted over the radio before transferring another frame over BCSP The RFCOMM firmware gives the application programming interface API access to the RFCOMM layer L2CAP layer SDP and device manager Direct access to the HCI layer is prohibited when an RFCOMM firmware build is used Some HCI commands and events are accessible via the Device Manager API For additional information on this version of RFCOMM firmware see 22 38 5 Software The software application can be split into the two sub programs The first subprogram 5 1 is a software interface between the output of SIM 1 the PROFIBUS PA data and the VO port of microcontroller MSP430 The second subprogram 5 2 is a software interface between the UART interface of microcontroller MSP430 and the UART interface of Bluetooth device BlueCore01 The common element of these two subprograms is a data buffer The first subprogram decodes the incoming PROFIBUS data and writes them to thi
43. days evaluation version The block diagram of interrupt service routine ISR2 is shown in the Figure 5 6 In the first step is read the sample of PROFIBUS bit and this is saved in the global variable Then is checked the terminating seguences end delimiter data link EDL maximal telegram length or wrong telegram When the terminating seguence is detected the parameters for interrupt service routine ISR1 are set and the control is switched into it On the other hand is checked if the start delimiter data link SDL is occurred After detection of start delimiter is checked if the whole NRZ byte is already read One NRZ byte contains 16 bits of Manchester code 5 1 1 1 2 If the NRZ byte is completed then it is saved to the common data buffer The theoretical number of assembler instructions in the interrupt service routine ISR2 is 37 instructions 5 1 3 The practical number depends on the used compiler MSPGCC or IAR Embedded Workbench for MSP430 the level of optimisation optimisation for size or for speed of code and the debugger s option debug or release version of compiled code the debug version adds some instructions for debugging to the compiled code The practical number of instructions for interrupt service routine ISR2 compiled by IAR Embedded Workbench for MSP430 in release version and optimized for size of code is following e odd sample bits of Manchester s coded data stream is read 32 instructions e even sample bits of Manches
44. e Host and on the Host Controller The BlueStack is accessible via BlueStack API Application Programming Interface The BlueStack API is defined as a set of message primitives A service primitive takes the form in software of a structure for example the RFCOMM primitive RFC START REO has the following structure typedef struct rfc prim t type Always RFC START REQ BD ADDR T bd addr Bluetooth device address psm t psm remote psm of remote device SYS PAR T Sys pars System parameters phandle t respond phandle Reply phandle overides dflt is set RFC START REQ T The primitive types are defined in the header file that describes the interface to the module in this example it would be RFCOMM and the header file is rfcomm prim h 9 p 72 107 BlueStack is supplied with the following elements Device Manager DM SDP 3 2 7 RFCOMM 3 2 6 TCS L2CAP 3 2 5 HCI Top 3 2 4 HCI Upper Driver UART RS 232 or BCSP e Scheduler services 30 Application Integration Layer o S eo m OK A S sa L2CAP API Device Mgr API L2CAP Device Mgr Hardware Independent Sourcecode available HCI API HCI Top HCI Upper Driver HCI Lower Driver HCI Bottom osy Link Manager 5 5 Link Controller S TE BASEBAND and Radio m Figure 3 15 BlueStack protocol layers HCI Bottom and the Link Manager have b
45. e at the very same time be a Remote for another SDP transaction The service discovery user application in a local device LocDev interfaces with the Bluetooth SDP client to send service inquiries and receive service inquiry responses from the SDP servers of remote devices RemDevs 25 The scenarios covered by this profile are the following e Search for services by service class searching for known services e Search for services by service attributes searching for specific services e Service browsing general service search Service discovery can be initiated by either a master or a slave device at any point for which these devices are members of the same piconet Also a slave in a piconet may possibly initiate service discovery in a new piconet provided that it notifies the master of the original piconet that it will be unavailable possibly entering the hold operational mode for a given amount of time For additional information on Service Discovery Application Profile see 8 p 63 98 3 4 BCSP BlueCore Serial Protocol 3 4 1 Introduction BCSP BlueCore Serial Protocol is a proprietary host transport protocol used on CSR s Cambridge Silicon Radio BlueCore Bluetooth chips It can be considered an alternative to the two host transport protocols UART RS 232 defined in the Bluetooth Specification v1 1 2 2 1 It operates over an RS 232 physical link but hardware flow control is optional BCSP has its own different methods
46. e is based on a nominal antenna power of 0 dBm Each device can optionally vary its transmitted power Bluetooth use a dynamical regulation of transmitted power At the master side the transmitted power is completely independent for different slaves a request from one slave can only affect the master s transmitted power for that same slave For additional information on Radio Specification see 3 p 15 32 3 2 2 Baseband specification The baseband is the physical layer of the Bluetooth It provides error correction flow control synchronization and security functions The Bluetooth baseband protocol is a combination of circuit and packet switching The Time Division Duplex TDD scheme is used for full duplex transmission where master and slave alternatively transmit The channel is represented by a pseudo random hopping sequence On the channel information is exchanged through packets Each packet is transmitted on a different hop frequency The channel is divided into time slots each 625 us in length the hop frequency is 1600 hops s A packet nominally covers a single time slot but can be extended to cover up to five slots The Bluetooth system provides a point to point or a point to multipoint connection Figure 3 2 In the point to multipoint connection the channel is shared among several Bluetooth units Two or more units sharing the same channel form a piconet All Bluetooth devices are peer units and have identical implementations
47. e robe bte n pk tsa lenis rated a eic nba Uo sask 47 5 2 2 Message sequence ss lc a hon 47 64 CONCLUSION conan 51 APPENDIX A Cte 52 APPENDIX B kanoe aa ak 53 DOCUMENT REFERENCES ssssssssnnnssnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn neneman 54 List of Figures Figure 2 1 Layered structure of Profibus protocol architecture eee 3 Figure 2 2 Hybrid access method to the common transmission medium at the Profibus 5 Figure 2 3 IEC telegram bottom and structure of the embedded FDL telegram 6 Figure 2 4 Waveform of the constant parts of the Profibus telegram IEC telegram 7 Figure 3 1 Bluetooth Protocol Stack as Specified by the Bluetooth SIG 11 Figure 3 2 Piconets with a single slave operation A a multi slave operation B and a scatternet operation Go a A eiut eh geese ean aii 13 Figure 3 3 Operating states in the Bluetooth System eee 15 Figure 3 4 Overview of the Lower Software LAyeTS were 16 Figure 3 5 HCI Command Par ns doba 17 Fig re 30 EC BV A et ate Sa ooo Cr A ol eaei 18 Figure 3 7 L2CAP layer in the Bluetooth Protocol Architecture eee 18 Figure 3 8 Multiple emulation serial ports itai tetto dios sa ea Pn Eo anios 20 Figure 3 9 Multiplexer and Service Channels Relationship Example 21 Figure 3 10 SDP Client Server ar din
48. ection is used in the PROFIBUS Bluetooth monitoring module For correct decoding is necessary to set the width of one bit T at the first time The Manchester encoding splits each bit period into two and ensures that there is always a transition between the signal levels in the middle of each bit That means one bit of 42 Manchester code includes two different levels Whence it follows that one bit must be read twice per period The optimal way is read the samples in the 4 and of bit s width Ti The initial sample is set at the T and next samples are read with distance of Ti The whole principle of decoding from Manchester to NRZ is shown in Figure 5 4 Sample points Bit period T lt gt a MANCHESTER DATA d 1 0 1 A V VLA 1 0 1 NRZ DATA Figure 5 4 Example of decoding from the Manchester code to the NRZ code The rules for decoding are summarized in Table 5 2 There are two adjacent values of an one bit of Manchester signal read in the T and T in the first column There are corresponding values of NRZ in the second column Two samples of Manchester One bit of NRZ 01 0 10 1 00 undefined illegal code 11 undefined illegal code Table 5 2 The decoding rules 5 1 2 Interrupt service routines Decoding 5 1 1 2 from the Manchester code which is used at the PROFIBUS PA bus to the NRZ code has two distinct phases synchronization to the b
49. ed or maximum frame size are negotiated for the link If the remote device requires a smaller frame size or needs to set a different value for initial credits then these parameters would need to be set in the RFC PARNEG RES primitive 48 e RFCOMM Establishment RFC ESTABLISH This primitive establishes the data link connection with negotiated DLC parameters referenced by the server channel on the multiplexer session MUX_ID Once the data link connection is available the data exchange can be started e Data transfer RFC DATAWRITE The data block with negotiated maximal frame size is transmitted with acknowledgement e Connection termiante RFC RELEASE RFC CLOSE Closing down the data link connection DLC referenced by the server channel and shutting down the multiplexer session and as a consequence all associated server channels 49 Read Local Bluetooth address Read Remote Bluetooth address Service Discovery Data Link Connection Connection Logical L2CAP channel Data transfer terminate MASTER SLAVE UART BCSP RADI Application 4 Local RFCOMM Sisson Remote RFCOMM r Application MSP 430 WML C06 Host Controller Host RFC REGISTER REQ gt a RFC REGISTER REQ RFC REGISTER CFM RFC REGISTER CFM gt RFC INIT REO gt RFC INIT REO RFC INIT CEM REC INIT CFM gt DM AM REGISTE
50. een implemented to the BlueCore single chip device from Cambridge Silicon Radio RFCOMM is a profile specific layer Serial Port Profile For example when developing a Bluetooth cordless telephone TCS binary would be used as the profile specific layer and not RFCOMM TCS Binary is a protocol that provides support for cordless telephony functionality over the Bluetooth air interface As a software component BlueStack reguires integrating with other software to realize a complete product This software may be an existing application or a completely new application The integration of existing application can be carried out in an Integration layer which sits between the application and BlueStack When the application is wholly new the application could be designed to interface directly to the RFCOMM API without Integration layer The exact integration approach taken also depends on the type of product being developed There are three categories of products that designers might consider Figure 3 16 e two processors standard solution involving a Host and Host controller where the higher layers have to be ported to and implemented on the Host where the physical split between higher and lower layers of the stack takes place at the HCI for example a PC based application e two processors embedded solution where the split between a Host and a Host controller does not take place at the HCI This allows products to be designed where the Host
51. egrams is marked by the preamble which is used for synchronization effect The next mark is start delimiter which represents a start of FDL telegram followed by itself FDL telegram The IEC telegram is terminated by the end limiter Figure 2 3 FDL Telegram K SDL LE LEr SDL DA SA FC Data Unit FCS EDL SDL Start Delimiter Data Link FC Frame control LE LEr Length byte FCS Frame check seguence DA Destination address EDL End delimiter Data Link SA Source address START END PREAMBLE DELIMITER FDL TELEGRAM DELIMITER 1 to 8 Bytes 1 Byte 1 to 256 Bytes 1 Byte IEC Telegram Figure 2 3 IEC telegram bottom and structure of the embedded FDL telegram The numeric values of three constant parts of the IEC telegram are in the Table 2 3 Note that the one bit is represented by two binary values Manchester code 5 1 1 1 2 Hexadecimal Binary Start Delimiter B24D 1011001001001101 End Delimiter B326 10 11 00 11 00 10 01 10 Preamble 9999 1001 1001 1001 1001 Table 2 3 Numeric values of constant parts of the Profibus telegram IEC telegram The waveform of these three marks is shown in Figure 2 4 With all data transmissions the parity and block checking of the telegrams is used to reach a Hamming distance of HD 4 so that up to three errors can be detected with certainty AII characters of frame are transmitted without gaps
52. ervice records that represent instances of that class Service Record Handle gt Service record SERVICE ATTRIBUTE 1 Service attribute SERVICE ATTRIBUTE 2 ATTRIBUTE ID SERVICE ATTRIBUTE 3 ATTRIBUTE VALUE SERVICE ATTRIBUTE 4 SERVICE ATTRIBUTE N Figure 3 11 Service record The service discovery protocol does not provide a mechanism for notifying clients when service records are added to or removed from an SDP server The whole point of the SDP is to allow Bluetooth devices to discover what other Bluetooth devices can offer what services SDP allows this in various means Searching means looking for specific service while Browsing means looking to see what services are actually being offered In the Service Discovery Protocol an attribute value is represented as a data element A data element is a typed data representation It consists of two fields a header field and a data field 3 p 349 Additional information regarding application interaction with SDP is contained in the Bluetooth Service Discovery Application Profile 3 3 3 For additional information on SDP see 3 p 331 392 3 3 Profiles The Profiles describe how the technology is used ie how different parts of the specification can be used to fulfill a desired function for a Bluetooth device The profile defines options in each protocol that are mandatory for the profile It also defines
53. ervice routine ISR2 is time critical Its maximal runtime is 13 875 us that represents maximal 37 assembler instructions The explanation of this result is given in this section An enter to the interrupt service routine takes 6 cycles further it must be allowed for up to 6 cycles in addition to complete the current instruction Return from interrupt service routine takes 5 cycles So even an empty interrupt service routine with no instructions requires up to 17 cycles that means 2 125 us 17x125 ns One instruction takes from 1 cycle up to 6 cycles that means approximately 3 processor cycles per instructions This three instruction cycles represent 375 ns Tryst 3x125 ns with 8 MHz s oscillator The PROFIBUS PA with the IEC 1158 2 transmission technology with Manchester coding 5 1 1 1 2 supports a constant transmission rate 31 25 Kbps One bit of Manchester code includes two different levels and therefore one bit must be read twice per period Whence it follows a double transmission rate 62 5 Kbps This baud rate is egual to the period of 16 us TsampLe This time presents a length of the second interrupt service routine ISR2 From the period of 16 us must be subtracted the maintenance time Tira enter to and return from the interrupt service routine which presents 2 125 us explained above in this section Tisr2 Tsampre Tintr 16 us 2 125 us 13 875 us 5 1 44 The runtime of the second interrupt service routine ISR2 Tr
54. es when using NRZ to encode a synchronous link which may have long runs of consecutive bits with the same value It is difficult for the receiver to recover clock signal and to distinguish one bit from another In positive logic NRZ the more negative or less positive voltage represents the low state and the less negative or more positive voltage represents the high state In negative logic NRZ the more positive or less negative voltage represents the low state and the less positive or more negative voltage represents the high state The example of NRZ signal is in Figure 5 2 CLOCK ORIGINAL DATA a NRZ DATA d Figure 5 2 Example of NRZ encoded data 5 1 1 1 2 Manchester Manchester encoding also know as Biphase Code is a synchronous the receiver uses a clock which is synchronized to the transmitter clock encoding technigue used to combine data and clock signals to form a single self synchronizing data bit stream A Manchester encoded signal contains freguent level transitions which allow the receiver to extract the 41 clock signal this allows the receiver to synchronize with the sender and correctly decode the value and timing of each bit In this technique the actual binary data to be transmitted over the link are not sent as a sequence of logic 1 s and 0 s known as Non Return to Zero NRZ 5 1 1 1 1 Instead the bits are translated into a slightly different format following the rules described in the
55. ess automation such as intrinsically safe transmission techniques power supply of field devices over the bus cable reliable data transmission and interoperability standardization of device functions The transition to the non hazardous area where Profibus is used with RS 485 technology is effected by a segment coupler or link installed between DP and PA segment From the point of view of the bus protocol it is transparent The coupler assumes the following tasks electrical isolation between the safe and the intrinsically safe bus segment powering of the PA bus segment adaptation of transmission technique from RS 485 to IEC 1158 2 baud rate adaptation if segment couplers are used the baud rate in the RS 485 segment is restricted to a maximum of 93 75 kbis s Pepperl amp Fuchs or 45 45 Kbps Siemens or 12 Mbps DP PA Link Siemens e conversion between asynchronous UART telegrams and synchronous 8 bit character telegrams The Profibus PA data telegrams of the IEC 1158 2 transmission are to a large extent identical with the FDL telegrams of the asynchronous RS 485 transmission Figure 2 3 The Profibus PA uses internationally recognized function block model to describe the device functions and parameters The function blocks represent different user functions such as analog input or analog output Every device have minimum three blocks physical function and transducer These blocks can be imagined like parts of control program Physi
56. fer is transfer via Bluetooth radio interface to the other Bluetooth suitable device Access to the BlueStack is via BlueStack API primitives 46 5 2 1 BlueStack concept The software application uses the Mezoe s BlueStack in the embedded two processors concept 3 5 In this concept the host is represented by the microcontroller MSP430 and the host controller is represented by the Bluetooth chip The BCSP uBCSP on the host presents L2CAP RFCOMM DM Device Manager and SDP APIs toward the application running on the host even though the layers themselves are on the host controller Figure 5 7 Application RFCOMM SDP DM L2CAP API API API API BCSP uBCSP Host UART Link BCSP uBCSP RFCOMM SDP Host L2CAP DM Controller HCI firmware Link Manager Link Controller Radio and Baseband Figure 5 7 Bluestack layers in the PROFIBUS Bluetooth monitoring module The BCSP uBCSP host transport protocol is used to transport the BlueStack primitives across a physical transport layer from the application to the BlueStack residing on another processor The host software controlling BlueStack via BCSP must encode BlueStack primitives in the BlueCore Friendly format BCF prior to sending the data to the BlueStack on the host controller as a BCSP payload The opposite conversion takes place on the host when BCSP payload is received This encode decode operatio
57. ice In this profile only connection oriented channels shall be used This implies that broadcasts will not be used in this profile This profile is built upon the Generic Access Profile 3 3 1 see Figure 3 12 All the mandatory optional reguirements defined in Generic Access Profile are mandatory optional for this profile The following roles are defined for this profile Initiator is the device that takes initiative to form a connection to another device Acceptor is the device that waits for another device to take initiative to connect The application layer procedures in the Serial Port Profile are following The Establish Link and Set up Virtual Serial Connection procedure supported by Initiator refers to performing the steps necessary to establish a connection to an emulated serial port in a remote device The steps in this procedure are 1 Submit a query using the Service Discovery Protocol SDP to find out the RECOMM Server channel number of the desired application in the remote device 2 Optionally require authentication of the remote device to be performed Also optionally require encryption to be turned on Request a new L2CAP channel to the remote RFCOMM entity Initiate an RECOMM session on the L2CAP channel 5 Start a new data link connection DLC on the RFCOMM session using the aforementioned server channel number M After step 5 the virtual serial cable connection is ready to be used for communication between app
58. ifak Ing Ond ej Dolej my supervisor of CTU and the others from forums and symposiums Contents 1 INTRODUCTION uestra 1 2 PROFIBUS eos are ee 2 2l A pelswausvcsess 2 22 ISO OSI rm e 2 2 2 1 Physical layers quete otav a e ted Re a hola en de ts bud Ends 3 2 2 2 Data link layer Fieldbus Data Link erect 4 2 2 4 1 Mediumi access protocol sid RS 4 2 2 2 2 Logical link COMMON ui oie tee orte ie nitas iso eie ed cadens 5 2 3 USER SPECI CATIONS ds ten e e rS id 7 2 3 1 Pronbus DP ie esteem Oo o ooo v let ue oo cet NIE RAIN 7 2 3 2 Profibus PA Lu s ORE ra E O e NEA T Poa 8 37 BLUETO O TH eee eee oe EM 10 Sel General Descriptions scccccescasesessccskseSsecessostecsoousyscesdesseucsbabpassoausbecsssdvbadsssesseasseespecses 10 3 1 1 IntroduetlODh di cti 10 3 1 2 Wireless standardse ias 11 A e A A SOSSE saos oaas TES a ona 11 3 2 1 Radio specificato sit ds 12 322 Baseband specification idees decade lada dx dice sa e ptores 12 3 333 Link Manager Protocol EMPD osea aid 15 3 2 4 Host Control Interface HT da na a e E 15 3 2 9 Logical Link Control and Adaptation Protocol L2CAP 18 3 2 6 RECOM Mis P it t 19 3 2 7 Service Discovery Protocol DP lan 21 A A O 22 3 3 1 Generic Access Profile GAP AAA mno de dha o eb ee deis 23 3 3 2 Serial Port Profile SPP Yak asd is AAT p e E p ba ARTINE 24 3 3 3 Service Discovery Application
59. ignal Input TxE Transmit Enable Input for enabling the sender RxS Receive Signal Receiver output RxA Receive Activity Output for display of line activity The SIM 1 supports 3 Operating Modes e Bus powered constant current consumption Constant Current Mode CCM The bus is loaded with a constant current The constant current can be set within the 4 mA up to 40 mA range This mode is used in the PROFIBUS Bluetooth monitoring module e Bus powered constant power consumption Constant Power Mode CPM The voltage drop is held constant e Locally powered Local Power Mode LPM In this mode the SIM 1 is locally powered by a 5 V supply The device doesn t consume any current from the bus For additional information on SIM 1 see 10 and 11 4 2 Texas Instruments MSP430F148 The MSP430 microcontrollers achieve maximum code efficiency with its ultra low power 16 bit RISC architecture The maximal external crystal frequency which can be used is 8 MHz That determines 125 ns Instruction Cycle Time ICT Typically only register instructions take 1 instruction cycle other instructions take up to 6 cycles depending on the addressing modes of the operands The instruction set consists of 24 core instructions and 27 emulated instructions with three formats and seven address modes The MSP430x14x series are microcontroller configurations with two built in 16 bit timers a fast 12 bit A D converter two universal serial synchronous asynchron
60. is resource limited for example an embedded host with limited resources such as a mobile phone e wholly embedded single processor solution where there is no external Host processor for example a wireless headset 31 There is no direct API provided for the control of the Link Manager from the application Control of the Link Manager from the application may be achieved indirectly using the HCI calls that are available via the Device Manager API BlueStack is designed to work with all of the Bluetooth specified HCI host transport protocols HCI commands and events are accessible via the Device Manager API 9 p 293 301 The interface associated with the Device Manager DM supports the following e HCI Commands and Events DM HCI e Security Manager primitives DM SM e Device Manager private primitives DM The information on the full set of primitives is contained in the header files dm prim h and hci h 9 p 219 288 Application Integration Layer Rc 2 pplication 2 RFCOMM SDP I Integration Layer o T L2CAP DM KD HCI RFCOMM SDP Iccos c Rm NEC ES L2CAP DM 5 E E HCI HCI S Link Manager 8 Link Manager Link Controller Link Controller o T BASEBAND and RF 4 BASEBAND and RF Standart two processor Embedded two processor architecture architecture Application Application Interface
61. it period and then sampling of the data bits For this reason there are defined two interrupt service routines These interrupt service routines never work all at once The interaction of these two interrupt service routines with the PROFIBUS s telegrams is shown in the Figure 5 5 43 The first interrupt service routine ISR1 detects the preamble of IEC telegram Figure 2 3 which is used for synchronization The timer in a capture mode is used for the measurement of the pulse width After detection of eight same pulses these form the preamble is calculated the sample time as a one half of a pulse width The first sample time is set to of the pulse width 5 1 1 2 and then the control is passed to the second interrupt routine ISR2 The second interrupt service routine ISR2 reads the samples of the data bits in the predefined sample time which was set by ISR1 The timer works in a compare mode After detection of start delimiter of IEC telegram the data bits are read in the sample time and then these samples are written to the common data buffer The data from this data buffer is transmitted via the Bluetooth interface 5 2 The procedure of decoding is explained in the section 5 1 1 2 After detection of end limiter of IEC telegram the control is passed back to the first interrupt routine ISR1 ISR2 ISRI Profibus PA Figure 5 5 Waveform of Interrupt Service Routines 5 1 3 Time calculation The second interrupt s
62. itting channels The UART character format consists of a start bit seven or eight data bits an even odd no parity bit an address bit 1n address bit mode and one or two stop bits The bit period is defined by the selected clock source and set up the baud rate registers The maximum USART baud rate is one third of the UART source clock frequency The transmitting and receiving functions use the same baud rate frequency For additional information on microcontroller MSP430 Timer see 23 p 227 257 4 3 Mitsumi s Bluetooth module WML C06 Wireless communication module based on CSR s BlueCore01 chip and conforming to Bluetooth Specification Version 1 1 It includes a radio chip BlueCore01 external Flash ROM and antenna on a single module The BlueCore01 chip together with an external Flash ROM containing the CSR Bluetooth software stack provides a fully compliant Bluetooth system for data and voice communications It supports communication up to 10 m class II There are enabled UART asynchronous serial interface USB PCM and SPI synchronous serial interface interfaces at this module The parameters of the Mitsumi s Bluetooth module WML 06 are following Bluetooth freguency 2402 up to 2480 MHz Number of channels 79 channels Power supply voltage 3 0 1V Current Consumption max 80 mA Maximum Data Rate Asynchronous 723 Kbps 57 6 Kbps Synchronous 433 9 Kbps 433 9 Kbps 36 The firmware can be downloaded to the Flash ROM mem
63. ke connections with respect to each other the DLCI value space is divided between the two communicating devices using the concept of RFCOMM server channels and a direction bit D DLCI D Server Channel Server channel is an association between an application service and a logical ID in RFCOMM Server applications registering with an RFCOMM service interface are assigned a Server Channel number in the range 1 30 This server channel should be registered in the Service Discovery Database 3 2 7 allowing remote devices to locate and connect to the application For an RFCOMM session the initiating device the device which setting up RFCOMM channel on L2CAP and starting RFCOMM multiplexing is given the direction bit D 1 and conversely D 0 in the other device As a consequence server channel 1 on the initiating device becomes DLCI 3 and server channel 1 on the other device becomes DLCI 2 and so on In other words server applications it is an application that awaits a connection from an client on another device on the non initiating device are reachable on even values of DLCI 2 4 6 60 and server applications on the initiating device are reachable on the odd values of DLCI 3 5 7 61 Note that for a device that supports multiple simultaneous RFCOMM sessions to two or more devices the direction bit might not be the same on all sessions At any time there must be at most one RFCOMM session between any pair of devices If a
64. l the peer layer N 1 responds with RES RSP and this result in a protocol message sends to protocol layer N Finally protocol layer N sends a confirmation CFM to Layer N 1 The result of the service reguest is recorded in a parameter in the CFM Not all service primitives have REO RES IND and CFM structures defined Peer layer N passes Peer layer N 1 Layer N 1 Layer N 1 is sent a service INDication to peer RESponds to the service REQuests a service confirmation CFM layer N 1 indication Protocol layer N Peer Protocol layer N Figure 3 17 Primitives with Layered Protocols Communication link Figure 3 18 shows how a protocol message is built up through the layers using service primitives DATA Layer N 1 Service Request Layer N ene Layer N Service Data Unit Layer N Service Request Layer N Protocol Data Unit Layer N 1 Header Layer N 1 Service Data Unit Layer N 1 Figure 3 18 Protocol message construction within a layered architecture For additional information on BlueStack see 9 33 4 Hardware This chapter briefly describes the hardware components used at the PROFIBUS Bluetooth monitoring module The concept of three main hardware components and interaction among them are shown in Figure 4 1 There are many other components such as resistors capacitors
65. laves can be connected to one bus The Profibus DP uses layers 1 and 2 from ISO OST reference model layers 3 to 7 are not used 2 2 Data transmission between the master and the DP slaves is divided into three phases parameterization configuration and data transfer Before a DP slave enters the data transfer phase the master checks in the parameterization and configuration phase whether the planned configuration matches the actual device configuration In the course of this check the device type format and length information as well as the number of inputs and outputs must agree For additional information on Profibus DP see 13 2 3 2 Profibus PA The Profibus PA Process automation was mainly designed for applications in explosion hazardous areas It permits the linking of sensors and actuators to a common bus cable also in hazardous areas It enables the data communication and energy supply for devices in two wire technology according to the international standard IEC 1158 2 2 2 2 1 The field devices in the hazardous area are connected via Profibus using IEC 1158 2 transmission technology Table 2 4 Transmission technique IEC 1158 2 Transmission rate 31 25 Kbps Intrinsic safety optional Bus supply optional Table 2 4 Physical Profibus PA layer Unlike the automated applications in manufacturing engineering which require short cycle times of few milliseconds other factors are of importance in proc
66. lications on both sides If there already exists an RFCOMM session between the devices when setting up a new data link connection the new connection must be established on the existing RFCOMM session This is eguivalent to skipping over steps 3 and 4 above 24 The Accept link and establish virtual serial connection procedure supported by Acceptor refers to taking part in the following steps 1 If reguested by the remote device take part in authentication procedure and upon further reguest turn on encryption 2 Accept a new channel establishment indication from L2CAP 3 Accept an RFCOMM session establishment on that channel 4 Accept a new data link connection on the RFCOMM session The Register Service record in local Service Discovery Protocol SDP database procedure supported by Acceptor refers to registration of a service record for an emulated serial port in the SDP database All services applications reachable through RFCOMM need to provide an SDP service record that includes the parameters necessary to reach the corresponding service application see 3 3 3 There are no SDP Service Records related to the Serial Port Profile in Initiator In the Table 3 1 is described the Serial Port related entries in the SDP database of Acceptor To retrieve the service records in support of this profile the SDP client entity in Initiator connects and interacts with the SDP server entity in Acceptor via the SDP procedures
67. lly controlled it can be halted read and written it can be stopped run continuously or made to count up or up down using one compare block to determine the period The three capture compare blocks are configured by the application to run in capture or compare mode The capture mode is mostly used to individually measure internal or external events from any combination of positive negative or positive and negative edges The compare mode is mostly used to generate timing for the software or application hardware or to generate pulse width modulated output signals An individual output module is assigned to each of the three capture compare registers Two interrupt vectors are used by this module One vector is assigned to first capture compare block CCRO and one common interrupt vector is implemented for the timer and the other two capture compare blocks The three interrupt events using the same vector are identified by an individual interrupt vector word For additional information on microcontroller MSP430 Timer see 23 p 151 185 4 2 2 USART There are two USART Universal Synchronous Asynchronous Receive Transmit peripheries implemented in the MSP430x14x USARTO and USARTI The USART supports synchronous SPI and asynchronous UART communication protocols This chapter discusses the operation of the asynchronous UART mode Two dedicated interrupt vectors are assigned to each USART module one for the receiving and one for the transm
68. mands ACL and SCO data These messages are translated to a stream of bytes which are sent to the UART e Bytes received from the UART are passed up into the BCSP stack These are translated into messages which are passed up Typical messages are HCI Events ACL and SCO data Channel Reliable Unreliable Notes 0 Not Available Not Available Used internally by BCSP for acknowledge packets 1 Unused BCSP Link Establishment Protocol 2 BCCMD Unused BlueCore Command Interpreter channel 3 HO Unused Host Ouery channel 4 DM Unused Device Manager 5 HCI emd evt Unsued HCI commands and events 6 HCI ACL Unused HCI ACL data 7 HCI SCO HCI SCO HCISCO data 8 L2CAP Unused 9 RFCOMM Unused 10 SDD Unused 11 Reserved Unused 12 DFU Unused Device Firmware upgrade 13 VM Unused Virtual Machine 14 Unused Unused 15 Reserved Reserved Table 3 2 BCSP channels allocation The following byte format is used One start bit Even parity bit Eight data bits One stop bit 27 To convert the RS 232 byte stream into a BCSP packet stream a version of the SLIP described in internet standard RFC 1055 packet framing is implemented The principle is to surround each packet with a start and an end special byte 0xC0 This allows the beginning and the end of a packet to be found and consequently the length of the packet to be known BCSP uses only one packet type Each BCSP packet includes
69. monitoring without wires and easy access toward the monitored devices without complicated configuration of the attached monitoring devices such as PCs PDA and etc The realized interface module works as a monitoring slave device in the PROBIBUS PA That means the data is transferred only in one direction from the PROFIBUS PA interface to the Bluetooth interface The Bluetooth specification reduces all interactions between devices to a short range low power ad hoc wireless connection The Bluetooth is a cable replacement technology From whence it follows the main advantage of the Bluetooth technology the connection without wired link and without the proprietary connectors The Bluetooth is mainly used in the commercial sphere therefore the cost of a Bluetooth chip is very low The next important characteristic of Bluetooth chips is its low power consumption The low power consumption is very important requirement for all chips designed at the interface module because the whole module is supplied from the PROFIBUS PA bus with the limited supply For portability the whole software was designed and developed in ANSI C language Hence the ANSI C Bluetooth protocol stack is applied The Mezoe s BlueStack was selected This document is structured to the four main chapters Profibus 2 Bluetooth 3 Hardware 4 and Software 5 The Profibus chapter describes the individual layers of ISO OSI model of PROFIBUS and a different version of PROFIBUS
70. n is translated between the host processor architecture and the architecture of the XAP2 microprocessor running on BlueCore01 4 3 1 The BCF encoding rules are designed to allow the host to generate primitives which are formatted according to the XAP2 compiler rules The data sending to the RFCOMM BlueStack and using BCSP uBCSP host transport protocol must observe the RFCOMM Packing rules outlined in the 25 or 18 The get uart and put uart functions from the uBCSP engine are system specific and will need to be modified with respect to the system specific UART in this case the UART periphery of MSP430 5 2 2 Message sequence The Figure 5 8 outlines the simple message sequence chart for set up a data link and pass data through it between the two Bluetooth devices with BCSP version of RFCOMM firmware The master device is responsible for initiating the link and the slave device is responsible for responding to the initiating device The following steps are required to set up a RFCOMM link between two Bluetooth devices 47 e Register with RFCOMM RFC REGISTER The application can register itself with a protocol handle phandle in the BlueStack RFCOMM layer RFCOMM will return a RFC REGISTER CFM primitive with an assigned server channel number The registered protocol handle will be used for notifying the application of the arrival of events for the given server channel The registration mechanism includes a protocol specific discriminat
71. n of transmit time for all stations and allows mobile stations to roam from cell to cell The access point routes data between the stations and other wireless stations or to and from the network server Documentation on Bluetooth is split into two sections the Bluetooth Specification 3 2 and Bluetooth Profiles 3 3 10 3 1 2 Wireless standards Other wireless standards based on the similar principles like a Bluetooth e The Infrared Data Association IrDA specifies three infrared communication standards IrDA Data IrDA Control and a new emerging standard called Alr Primarily IrDA is point to point it is very directional it will not transcend opaque materials and etc e Airport is a wireless communications system which like Bluetooth is based on the IEEE 802 11 recommendation It also uses 2 4 GHz frequency band but its range is about 45 meters and it boasts a transmission speed of 11 Mbps It is developed by Lucent Technologies and used with Apples Macintosh e Wireless LAN technology WLAN is based on the same communications standard like Bluetooth IEEE 802 11 and uses the same frequencies for carriers But there the similarities end WLANs use ordinary LAN protocols for communication Nor is Bluetooth meant for transmitting huge amounts of data as are LANs and WLANS Bluetooth puts its emphasis on dynamically handling mobile units of various kinds e Wi Fi is the name of a similar but simpler technology based on the IE
72. oftware programs and for radio interface is used a Bluetooth module Mitsumi WML C06 based on the CSR s Cambridge Silicon radio BlueCore01 chip On the Bluetooth chip runs RFCOMM firmware with embedded two processors architecture The Mezoe s BlueStack is used as a Bluetooth protocol stack BCSP uBCSP host transport protocol runs on the UART link between host MSP430 and host controller Bluetooth chip Anotace Data z pr myslov sb rnice PROFIBUS PA jsou p en ena p es r diov rozhran Bluetooth do p stroje kter umo uje p jem dat po tomto r diov m rozhran nap PC PDA atd Na vyv jen m modulu byly pou ity n sleduj hlavn hardwarov komponenty ASIC obvod SIM 1 firmy Siemens pro nap jen cel ho modulu ze sb rnice PROFIBUS PA a pro pravu sign lu z t to sb rnice hlavn mikrokontroler MSP430F148 firmy Texas Instruments pro uchov n a b h psan ho programu a pro r diov rozhran Bluetooth modul WML C06 firmy Mitsumi zalo en na obvodu BlueCore01 firmy Cambridge Silicon Radio CSR Tento Bluetooh modul obsahuje RFCOMM firmware s vestav nou dvou procesorovou architekturou BlueStack firmy Mezoe byl pou it jako Bluetooth protocol stack BCSP uBCSP byl zvolen jako transportn protokol mezi mikrokontroler a Bluetooth modulem Acknowledgements This thesis could not be accomplished without the help and support of Dipl Ing Andr Gnad Dipl Ing Heiko Adamczyk and Dr Lutz Rauchhaupt all from
73. oia 21 Pag aie LL SEI i e c tp re e E vs quU pa vehe E dan 22 Figure 3 12 Bluetooth Profiles Dependencies trs dik tasa aei ides 23 Fig r 3 13 BOSP CODICE one Or E RE 2T Figure 3 14 ABCSP stack s external IET 29 Figure 5 15 BlueStack protocol layers venida adas 31 Figure 3 16 BlueStack Me eration ase testes eU oko Mada sat ahead sa abe uie ed 32 Figure 3 17 Primitives with Layere d Protogolsa sada ela ed deni ed 33 Figure 3 18 Protocol message construction within a layered architecture 33 Figure 4 1 Hardware conception of PROFIBUS Bluetooth monitoring module 34 Figure 5 1 The hierarchical structure of program files iu id 40 Figure 5 2 Example of NRZ encoded data os actos re de stes sevi tape Etre epa Nimis 41 Figure 5 3 Example of the Manchester encoded data eee eee 42 Figure 5 4 Example of decoding from the Manchester code to the NRZ code 43 Figure 5 5 Waveform of Interrupt Service Routines essere 44 Figure 5 6 Block diagram of interrupt service routine ISR2 eee 46 Figure 5 7 Bluestack layers in the PROFIBUS Bluetooth monitoring module 47 Figure 5 8 Message sequence chart for data link set up between two BlueCore devices 50 List of Tables Table 2 1 Table 2 2 Table 2 3 Table 2 4 Table 3 1 Table 3 2 Table 5 1 Table 5 2 Basic characteristics of
74. ollowing types of devices e Master devices active stations with bus access control determine the data communication on the bus A master can send messages without an external request when 1t holds the bus access rights the token There are two types of master device class I master DPMI is a central controller e g a PLC or PC which cyclically exchanges data with the distributed stations slaves in a defined message cycle and class 2 master DPM2 configuration diagnostic monitoring and maintenance devices using acyclic communication to communicate with other devices class 1 master or slaves e Slave devices passive stations without bus access control are peripherals such as I O devices valves drivers and measuring transducers They have no bus access rights and they can only acknowledge received messages or send a response message to the master 2 2 ISO OSI model As indicated above the Profibus is based on the layered ISO OSI International Standard Organization Open System Interconnection communication model for open system communication refer to ISO 7498 standard This specification defines 7 layers but the Profibus uses only 3 layers of them Layer 1 Physical Layer Layer 2 Data Link Layer and Layer 7 Application Layer The remaining layers Layers 3 to 6 are empty to minimize expense and increase efficiency time reaction The architecture is shown in the Figure 2 1 e Physical layer 1 layer defines the
75. ondence to the ISO OSI reference model The Medium Access Control MAC must ensure that only one station has the right to transmit data at the time Profibus is a multi master system and thus allows the operation of several automation engineering or visualization systems with their distributed peripherals on one common bus The hybrid bus access control system operates on the token passing method among the master devices and uses the master slave principle to communicate between master and slave devices The token passing procedure ensures that the bus access right the token is assigned to each master within a precisely defined time frame It allows him to have an exclusive control over the communication network within that time frame The token must be passed around the logical token ring once to all masters in order of increasing addresses within a maximum token rotation time The master slave procedure permits the master the active station that currently owns the token to access the assigned slaves the passive stations This enables the master to send the messages to or to receive the response messages from the slaves Figure 2 2 Token Passing Figure 2 2 Hybrid access method to the common transmission medium at the Profibus Master Slave When an active station receives the token telegram it can communicate with all slave stations in the master slave communication relationship and all master stations in
76. or so that the association between phandle and the layer specific discriminator is made In the case of RFCOMM this is the local server channel in the case of L2CAP this is the Protocol Service Multiplexer PSM e Initialize RFCOMM RFC INIT It registers the PSM and protocol handle phandle to which remote requests to start an RFCOMM session will be sent via RFC START IND events This call cause that RFCOMM registers itself with L2CAP using the RFCOMM PSM value RFC INIT may also optionally be used to set flow control parameters e Register with Device Manager DM DM AM REGISTER The application can register itself in BlueStack Device Manager Registering a destination protocol handle phandle for upstream application primitives This allows access to functions such as inquiry inquiry scanning paging and page scanning and etc e Local Bluetooth address DM HCI READ BD ADDR This primitive reads the value for the BD ADDR parameter local Bluetooth address The BD ADDR is a 48 bit unique identifier for a Bluetooth device 3 2 2 e Remote Bluetooth address DM HCI INQUIRY DM HCI RESULT DM HCI INQUIRY COMPLETE The DM HCI INOUIRY primitive cause that the Bluetooth device enters to Inguiry Mode Inguiry Mode is used to discovery other nearby Bluetooth devices DM HCI RESULT event will be created for each Bluetooth device which responds to the Inguiry message This event contains the Bluetooth address of remote Bluetooth device DM HCI INOUIRY
77. ory through the SPI Serial Peripheral Interface interface with BlueFlash utility The PSTool utility allows programming of BlueCore s persistent store keys over SPI interface too The Persistent Store PS Keys are necessary for configuration the BlueCore01 chip Briefly description of each of the Persistent Store keys is in 20 BlueFlash and PSTool utilities are members of BlueSuite Development tool 21 For additional information on Mitsumi s Bluetooth module WML C06 see 15 4 3 1 CSR s BlueCore01 chip BlueCore01 is a true single chip for the Bluetooth 2 4 GHz implemented in CMOS technology On the BlueCore01 chip runs a 16 bit RISC microcontroller with XAP2 architecture All memory is 16 bit wide at this architecture The XAP2 has no 8 bit type The XAP2 architecture cannot address the byte stored in the high half of a memory location A consequence of this is that sizeof uint16 and sizeof uint8 return the same value on the XAP2 architecture 1 e 1 For more information on XAP2 architecture see 18 and 19 Signals UART_TX UART_ RX UART_RTS and UART_CTS form a conventional asynchronous data serial interface This interface is programmable with these parameters Baud rate selectable 115200 bps default Data bits 8 bits Parity ON or OFF default Stop bits 1 bit default or 2 bits Flow Control RTS CTS default or none For additional information on CSR s BlueCore01 chip see 16 and 17 4 3 2 RFCOMM
78. ous communication interfaces USART and 48 I O pins six 8 bit ports The specific version MSP430F148 which is used in this PROFIBUS Bluetooth monitoring module has 48 KB 256 B Flash Memory and 2KB RAM available A clock distribution block allows the three clock sources LFXT1 XT2 and DCO to be connected to the three internal clocks ACLK MCLK and SMCLK in a wide range of configurations There are six 8 bit I O ports implemented ports P1 through P6 Every I O pins are individually configurable for input or output direction and each I O line can be individually read or written Interrupt processing of external events is fully implemented for all eight bits of ports P1 and P2 two interrupt vectors Each interrupt for the P1 and P2 I O lines can be individually enabled and configured to provide an interrupt on a rising or falling edge of an input signal For additional information on microcontroller MSP430 see 23 or 24 4 2 1 Timer There are two build in timers in the microcontroller The Timer A module offers one 16 bit counter and three capture compare registers The Timer B module offers one configurable 16 12 10 8 bit counter and seven capture compare registers The function of Timer B 35 is slightly different from Timer A The timer clock source can be selected from two external sources or from two internal sources ACLK or SMCLK The clock source can be divided by one two four or eight The timer can be fu
79. parameter ranges for each protocol The profile concept is used to decrease the risk of interoperability problems between different manufacturers products In Figure 3 12 the Bluetooth profile structure and the dependencies of the profiles are depicted A profile has dependencies on the 22 profile s in which it is contained directly and indirectly For example the Object Push profile is dependent on Generic Object Exchange Serial Port and Generic Access profiles A number of additional Bluetooth profiles are currently in the development Generic Acces Profile 3 3 Service Discovery App Profile PAN Profile TCS BINARY Based Profiles Audio Video Remote Control Intercom Profile Profile Cordless Telephony Profile Common ISDN Access Profile Serial Port Profile Headset Profile LAN Profile Dial up Networking Profile SIM Access Profile Fax Profile Hands Free Profile Generic Object Exchange Profile File Transfer Profile Synchronization Profile Object Push Profile Basic Imaging Profile Basic Printing Profile Figure 3 12 Bluetooth Profiles Dependencies 3 3 1 Generic Access Profile GAP This profile defines the generic procedures that can be used for discovering identities names and basic capabilities of other Bluetooth devices that are in a mode where they can be discoverable Essentially this p
80. passive line termination at both ends Since the electrical power in the segments is limited in explosion hazardous areas due to intrinsic safety requirements the number of connectable field devices is limited as well Depending on the explosion requirements and energy consumption of the devices 10 EEx up to 32 non explosive devices can be linked up in one segment 13 Medium twisted pair shielded or unshielded Number of station 32 stations in each segment without repeater Transmission 31 25 Kbps synchronous Manchester coding Topology line star and tree or a combination Remote powering power supply using the bus cable Table 2 2 Basic characteristics of IEC 1158 2 transmission technology e Fiber Optic conductors may be used in Profibus for application in environments with very high electromagnetic interference for electric isolation or to increase the maximum network distance for high transmission speeds Maximal length of bus depends on the type of optical fiber glass synthetic and can be extended up to 80 km range Profibus segment using fiber optic technology are designed using either a star or a ring structure Many manufactures also offer couplers between RS 485 transmission links and optical fibers 13 2 2 2 Data link layer Fieldbus Data Link 2 2 2 1 Medium access protocol AI versions of Profibus use identical medium access protocol This protocol is implemented in layer 2 with corresp
81. ported by the implementation In addition RFCOMM has its own flow control mechanisms Credit base flow the one of flow control mechanism is a mandatory feature that did not exist in RFCOMM in Bluetooth specifications v1 0B and earlier 1 p 415 419 If all L2CAP channels towards a certain device are idle for a certain amount of time a decision may be made to put that device in a low power mode i e use hold sniff or park mode This will be done without any interference from RFCOMM For additional information on RFCOMM see 8 p 393 424 3 2 7 Service Discovery Protocol SDP The Service Discovery Protocol SDP allows Bluetooth devices to discover what services applications are available or to find a Bluetooth device that supports a specific service without previous knowledge of the Bluetooth address of that device The Service Discovery Protocol is client server architecture The server maintains a list of service records that describe the characteristics of services associated with the server Each service record contains information about a single service application A client may retrieve information from a service record maintained by the SDP server by issuing an SDP request Figure 3 10 There is a maximum of one SDP server per Bluetooth device if a Bluetooth device acts only as a client then needs no SDP server A single Bluetooth device may function both as an SDP server and as an SDP client
82. r Figure 3 6 17 0 16 31 P ter Total Event Code ee ners Parameter 0 Lenght Parameter 1 Parameter Parameter N 1 Parameter N Figure 3 6 HCI Event Packet For additional information on Host Control Interface see 3 p 535 826 3 2 5 Logical Link Control and Adaptation Protocol L2CAP Logical Link Control and Adaptation Protocol L2CAP provides connection oriented and connection less data services to upper layer protocols with protocol multiplexing capability segmentation and reassembly operation and group abstractions L2CAP permits higher level protocols and applications to transmit and receive L2CAP data packets up to 64 Kbytes in length The L2CAP Specification is defined for only ACL links and no support for SCO links 3 2 2 Voice channels SCO links for audio and telephony applications are usually run directly over baseband SCO links Packetized audio data such as IP Telephony may be sent using communication protocols running over L2CAP Figure 3 7 SDP RFCOMM TCS AUDIO LMP L2CAP VOICE ACL SCO BASEBAND Figure 3 7 L2CAP layer in the Bluetooth Protocol Architecture L2CAP must support protocol multiplexing because the Baseband Protocol 3 2 2 does not support identification of the higher layer protocols being multiplexed above it L2CAP must be able to distinguish between upper layer protocol
83. rofile describes how the lower layers LMP and Baseband are used along with some higher layers For the descriptions in this profile of the roles that the two devices involved in a Bluetooth communication can take the generic notation of the A party the paging device in case of link establishment or initiator in case of another procedure on an established link and the B party paged device or acceptor is used Bluetooth devices that do not conform to any other Bluetooth profile shall conform to this profile to ensure basic interoperability and co existence With respect to inquiry procedure 3 2 2 a Bluetooth device shall be either in non discoverable mode or in a discoverable mode limited discoverable and general discoverable mode The device shall be in only one mode at a time When a Bluetooth device is in the non discoverable mode it does not respond to inquiry With respect to paging procedure 3 2 2 a Bluetooth device shall be either in non connectable mode or in connectable mode When a Bluetooth device is in the non connectable mode it does not respond to paging With respect to pairing procedure 3 2 3 a Bluetooth device shall be either in non pairable mode or in pairable mode In pairable mode the Bluetooth device accepts paring 1 e creation of bonds initiated by the remote device and in the non pairable mode it does not The purpose of the link establishment procedure is to establish a physical link of ACL type between
84. s common data buffer The second subprogram forms an RFCOMM link between two Bluetooth devices and then passes data from the common data buffer between them There are the header and C source files used in the software application which runs on the PROFIBUS Bluetooth monitoring module The following files need to be compiled and linked together The hierarchical continuity among the files is shown at the Figure 5 1 e main c C Source file containing the main functions which associate PROFIBUS res1 c and Bluetooth b ue c parts e main h Header file contains application specific definitions and prototypes for main c e Dtypes h Header file contains the type definitions used in the ifak company e types h Header file contains the general type definitions e blue c C Source file joins the primitives from files below and establish maintenance and close the Bluetooth link e blue h Header file contains the type definitions and prototypes for blue c source file e bluetoot h Header file contains the Bluetooth specific type definitions e dm c C Source file contains the access to BlueStack device manager primitives e dm h Header file contains dedicated device manager specific definitions and prototypes for dm c source file e dm prim h Header file defines device manager primitive definitions and messages e hci h Header file contains HCI definitions and messages e rfcomm c C Source file contains the a
85. s concept The slave can leave the active state and waits in several power saving modes At the end of transmission path was used the laptop computer with the TDK PCMCIA Bluetooth card The maximal RFCOMM frame size for this Bluetooth card is set to the fixed value of 127 bytes This RFCOMM frame size did not give the maximum throughput at higher baud rates and held down the transfer rate of whole transmission path This diploma thesis was realized during my intership at the Institut f r Automation und Kommunikation e V ifak Magdeburg Germany and was used for check the availability Bluetooth technology in process automation In the future it can be applied for the remote monitoring of industrial devices 51 Appendix A All documents mentioned in the section Document References are on the attached CD ROM On the same CD ROM are also attached the source codes of application The structure of CD ROM is following e Documentation Referenced documents e Programs Source Code IAR ANSI C source codes of application suitable for the IAR Embedded Workbench for MSP430 version 2 10A 52 Appendix B pragma vector TIMERA1 VECTOR interrupt void ManDecSamplelnterruptHandler void UInt8 InputRegister input register from port UInt16 InterruptRegister TAIV accessing the TAIV register for reseting the highest interrupt flag CCRI RES gVar ManDecSampleTime count next sample time P20UT 0x04 testing point toggle
86. s created based on a PIN a random number and a Bluetooth Device address When both devices have calculated Kini the link key is created in the pairing procedure and finally a mutual authentication is made For additional information on Link Manager Protocol see 3 p 183 251 3 2 4 Host Control Interface HCI The Host Controller Interface HCT provides a command interface to the Baseband Link Controller and Link Manager and access to hardware status and control registers The HCI exists across 3 sections the Host the Transport Layer and the Host Controller Each of the sections has a different role to play in the HCI system Figure 3 4 15 Bluetooth Host Higher Layer y HCI Driver Y Software Physical Bus Driver Physical Bus USB UART Firmware Physical Bus Firmware Hardware HCI Firmware y Link Manager Firmware Baseband Controller Bluetooth Host Controller Hardware Figure 3 4 Overview of the Lower Software Layers The HCI Firmware is located on the Host Controller The term Host Controller means the HCl enabled Bluetooth device The HCI firmware implements the HCI Commands for the Bluetooth hardware by accessing baseband commands link manager commands hardware status registers control registers and event registers The term Host means the HCI enabled
87. s such as the Service Discovery Protocol SDP 3 2 7 RFCOMM 3 2 6 and etc Protocol multiplexing is based on the concept of channels A channel represents a data flow between L2CAP entities in remote devices Multiple channels can be bound to the same protocol but a channel cannot be bound to multiple protocols Each L2CAP packet received on a channel is directed to the appropriate higher level protocol SDP RFCOMM A Channel identifier CID identifies each endpoint of the L2CAP channel The same CID is not reused as a local L2CAP channel endpoint for multiple simultaneous L2CAP channels between a local device and some remote 18 device The device can assign CIDs independently from other devices Channels may be connection oriented or connection less An L2CAP implementation segments higher layer packets into chunks that can be passed to the Link Manager via the Host Controller Interface HCI where they will be converted into Baseband packets On the receiving side an L2CAP implementation receives chunks from the HCI and reassembles those chunks into L2CAP packets using information provided through the HCI and from the packet header The Segmentation and Reassembly SAR functionality is absolutely necessary to support protocols using packets larger than those supported by the Baseband protocol 3 2 2 In the concept of data packet format is used the term Protocol Service Multiplexer PSM The PSM value must be odd Also all PSM values mus
88. sg2 must be less than or equal to the period of 13 875 ys If one instruction takes approximately 375 ns then the maximal number of instructions per the second interrupt service routine is equal to 37 assembler instructions Tu 13 875 us _ Tinsi 375 ns 37 5 2 At the selected microcontroller MSP430F148 the first interrupt service routine ISR1 is no time critical but the second interrupt service routine ISR2 is time critical In practice the runtime of the first routine ISR1 the synchronization routine must be less than or equal to 29 875 us 31 25k 2 125 us and the runtime of the second routine ISR2 the sample routine must be less than or equal to 13 875 us 5 1 4 Interrupt service routine ISR2 Implementation Two compilers suitable for microcontroller MSP430 were used in this work The one of them is MSPGCC It is a port of the GNU C Compiler GCC for the embedded processor MSP430 MSPGCC is a completely free and unlimited C compiler for Texas Instruments s MSP430 series of microcontrollers The compiled source code can be downloaded over the JTAG interface to the microcontroller using C Spy utility from the IAR Embedded Workbench for MSP430 The IAR Embedded Workbench for MSP430 is an integrated development environment with compiler download and debug utilities and is not free Two limited versions exist for this software tool version limited in the size of compiled code maximum 4 kB or time limited version 30
89. t be assigned such that the least significant bit of the most significant octet is zero The PSM value definition is specific to L2CAP and is assigned by the Bluetooth SIG The PSM values are separated into two ranges Values in the first range are assigned by the Bluetooth SIG and indicate target protocols 0x0001 Service Discovery Protocol 0x0003 RECOMM 3 p 280 The second range of values are dynamically allocated and used in conjunction with the Service Discovery Protocol SDP 3 2 7 For additional information onL2CAP see 3 p 253 330 3 2 6 RFCOMM The RFCOMM is a simple transport protocol which provides emulation of RS 232 serial ports 9 circuits over the L2CAP protocol RFCOMM layers communicate with each other through the use of frames and these frames make up the data payload of a L2CAP packet The RFCOMM protocol is based on the ETSI standard TS 07 10 Only a subset of the TS 07 10 standard is used and in addition some adaptations of the protocol are specified in the Bluetooth RFCOMM specification The RFCOMM protocol supports up to 60 opened emulated ports between two Bluetooth devices The port instance is identified by the Data Link Connection Identifier DLCI The DLCI usable value range for ports is 2 to 61 The DLCI is unique within one RFCOMM session between two devices To account for the fact that both client and server applications may reside on both sides of an RFCOMM session and are able to independently ma
90. ter s coded data stream is read two subsequent Manchester s bits are decoded to one NRZ bit 36 instructions e one NRZ bytes is equal to16 Manchester s bits is written to common data buffer 32 instructions e odd sample bits of Manchester s coded data stream is read and simultaneously the start delimiter SDL is detected 38 instructions e even sample bits of Manchester s coded data stream is read and simultaneously the start delimiter SDL is detected 42 instructions 45 From whence it follows when the start delimiter data link SDL is detected then the synchronization problem is occurred for a reading of the next data bits Only the bits of start delimiter SDL is read with right synchronization Sample reading and storage Leave the ISR2 DES ISRI s parametrs setting 9 o and switching to ISRI m The Start delimiter No SDLwas detected The 16 Manchester s bits Saving one NRZ byte to Y 1 NRZ s byte was common data buffer read Manchester to NRZ decoding q Figure 5 6 Block diagram of interrupt service routine ISR2 The source code of interrupt service routine ISR2 is available in the Appendix B 5 2 Software interface Microcontroller Bluetooth This chapter describes how the BlueStack on the host controller is accessed via the BCSP uBCSP channels from the host and how the PROFIBUS data from common data buf
91. ueCore Serial Protocol 5 is optimized to limit the RAM usage and can work with small memory pool buffers The penalty for this is that it uses more processing power ABCSP is good for embedded applications where RAM usage is important and will if sufficient processing power is available provide good throughput The ABCSP library must first be initialized by a call to abcsp init To send a message higher layer code calls abcsp sendmsg this places the message into a queue within the library The message includes HCI commands ACL data or SCO data The higher layer code then repeatedly calls abcsp pumptxmsgs to translate the message into its BCSP wire format and push these bytes out of the bottom of the library via ABCSP UART SENDBYTES For inbound messages the UART driver code passes BCSP wire format bytes into the library via calls to abcsp uart deliverbytes When the library has all of the bytes to form a complete higher layer message it calls ABCSP DELIVERMSG to pass this to higher layer code In the Figure 3 14 function names in lower case are part of the library code Function names in upper case are macros within the code The external environment must implement these according to definitions given in ABCSP source header files YABCSP Yet Another BlueCore Serial Protocol 6 is optimized to limit the processing power requirements The penalty for the optimization is that it uses more and larger chunks of RAM than ABCSP YABCSP s
92. upports multiple instances YABCSP was written with almost 28 the same interface as ABCSP Hence switching to from ABCSP to YABCSP is extremely easy Functions given in the API to from the Y ABCSP are similar to functions in the API to from the ABCSP extended about the pointer to a specific instance Higher Layers es ABCSP DELIVERMSG ABCSP Library abcsp init ABCSP UART SENDBYTESQ A besp vart deliverbyies0 UART Driver UART Figure 3 14 ABCSP stack s external interface 3 4 2 2 uBCSP uBCSP is intended for designs that want to implement BCSP and are using a small embedded microcontroller unit MCU as the Host processor interfaced to a BlueCore device Host controller where the memory resource is the main concern and the speed of data throughput is of secondary concern Some compromises must be made to achieve the resource savings over the full implementation of BCSP uBCSP uses a window size of one packet the full implementation of BCSP permits a window size of up to seven packets The overall effect is to reduce the RAM and read only memory ROM requirements on the Host The use of the single window scheme has another impact on memory size due to the fact that the memory is fixed it can now be statically allocated by the linker The uBCSP engine is consists of the following files e ubcsp c functions that are generic to any implementation of uBCSP e ubcsp h header
93. with development of Bluetooth in 1994 The Institute of Electrical and Electronic Engineers IEEE has developed and approved a new wireless standard 802 15 1 that is fully compatible with Bluetooth As with Bluetooth the new standard has a smaller transmission range and lower speed than the 802 11 standard although both standards run in the unlicensed ISM Industrial Scientific Medicine band at 2 4 GHz The 802 15 1 standard is supported by the Bluetooth Special Interest Group SIG Bluetooth technology has been designed to operate in noisy radio frequency environments and uses a short acknowledgement and fast freguency hopping scheme to make the link robust communication wise Compared with other systems operating in the same freguency band the Bluetooth radio typically hops faster and uses shorter packets This is because short packages and fast hopping limit the impact of microwave ovens and other sources of disturbances Bluetooth is based on the IEEE 802 11 standard This standard defines the protocol for two types of networks Ad hoc and client server networks e An Ad hoc network is a simple network where communications are established between multiple stations in a defined coverage area without the use of an access point or server The standard specifies the etiguette that each station must observe so that they all have fair access to the share wireless media e The client server network uses an access point that controls the allocatio
94. y determined by the choice of transmission technology As well as general demands made on bus system such as high transmission reliability large distances and high transmission speed in process automation additional requirements must also be satisfied such as operation in hazardous areas and transmission of data and energy on a common cable Since it is not possible to satisfy all requirements with a single transmission technology therefore exist three transmission methods physical profiles available for Profibus e RS 485 high speed H2 is especially used for the Profibus DP FMS It covers all areas in which a high transmission speed and simple cost effective installation are required A shielded twisted cooper cable with one conductor pair is used It is a serial communication interface All devices are connected in a bus structure parallel The bus structure permits addition and removal of stations or step by step commissioning of the system without affecting the other stations Later expansions have no influence on the stations which are already in operation Transmission speed is available between 9 6 Kbps and 12 Mbps One unique transmission speed is selected for all devices on the bus The maximum cable length depends on the transmission speed higher speed baud rate shorter cable length Kbps Kilobits per second 2 Mbps Megabits per second in the segment Using repeaters can extend the cable length Up to 32 st

PROFIBUS-PA monitoring with Bluetooth interface

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