DE19549815B4 - Serial bus connection equipment eliminating functional interference - couples main transmitter and receiver units divided into sub-groups enabling high speed communication - Google Patents

Serial bus connection equipment eliminating functional interference - couples main transmitter and receiver units divided into sub-groups enabling high speed communication

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Publication number
DE19549815B4
DE19549815B4 DE19549815A DE19549815A DE19549815B4 DE 19549815 B4 DE19549815 B4 DE 19549815B4 DE 19549815 A DE19549815 A DE 19549815A DE 19549815 A DE19549815 A DE 19549815A DE 19549815 B4 DE19549815 B4 DE 19549815B4
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Germany
Prior art keywords
transmission
messages
characterized
message
control unit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
DE19549815A
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German (de)
Inventor
Lars-Berno Fredriksson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
XINSHU MANAGEMENT L.L.C., DOVER, DEL., US
Original Assignee
Kvaser Consultant AB
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Filing date
Publication date
Priority to SE9401305 priority Critical
Priority to SE9401305A priority patent/SE501984C2/en
Application filed by Kvaser Consultant AB filed Critical Kvaser Consultant AB
Priority to DE1995114696 priority patent/DE19514696B4/en
Priority claimed from DE1995114696 external-priority patent/DE19514696B4/en
Application granted granted Critical
Publication of DE19549815B4 publication Critical patent/DE19549815B4/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00Data switching networks
    • H04L12/28Data switching networks characterised by path configuration, e.g. local area networks [LAN], wide area networks [WAN]
    • H04L12/40Bus networks
    • H04L12/407Bus networks with decentralised control
    • H04L12/413Bus networks with decentralised control with random access, e.g. carrier-sense multiple-access with collision detection (CSMA-CD)
    • H04L12/4135Bus networks with decentralised control with random access, e.g. carrier-sense multiple-access with collision detection (CSMA-CD) using bit-wise arbitration
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00Data switching networks
    • H04L12/28Data switching networks characterised by path configuration, e.g. local area networks [LAN], wide area networks [WAN]
    • H04L12/46Interconnection of networks
    • H04L12/4604LAN interconnection over a backbone network, e.g. Internet, Frame Relay
    • H04L12/4616LAN interconnection over a LAN backbone
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00Data switching networks
    • H04L12/28Data switching networks characterised by path configuration, e.g. local area networks [LAN], wide area networks [WAN]
    • H04L12/40Bus networks
    • H04L2012/40208Bus networks characterized by the use of a particular bus standard
    • H04L2012/40215Controller Area Network CAN

Abstract

Main groups (2,3) of transmitter and receiver units are divided into sub-groups (4,5,6,7,8,9,10). The main groups are activated one at a time, whilst the remaining main group is passive. The number of sub-groups can vary and they can include one or more transmitter and receiver units. The bus connection can be two-wired with branches. One receiver (4) acts as master unit provided with two transmitter and receiving units and a micro-data control unit. A further master unit (7) is formed in a corresp. way to the first (4). The units which do not have a master function in the respective main groups (e.g. 8) have only one transmitter/receiver unit with corresp. micro-control unit. The activated main group works with dominant signals in a receiving function or an access and receiving function between the sub-groups of transmitter and receiving units.

Description

  • The The present invention relates to an arrangement for disposal a fault or faults in a series circuit, connected to the transmitting and receiving devices are. As a supplement or alternatively, the invention may be a high speed transmission between the devices or enable their groups. The circuit operates in this case by means of digital transmission. The Circuit can take one of two signal states, one of which first signal state, which can be represented by a zero, over the second Signal state dominated, which in this case represented by a one can be. Each transceiver is designed to be eavesdropping and transmit switch positions, and each device is in addition it designed with a certain access to the circuit Form of connection function can work. In this context can the time-based protocols or a so-called Chaining protocol (or protocol of a serial priority circuit) or a decision function. In the latter case sends the device concerned a signal in accordance with the second state or hears. When the unit is in this listening position no dominant signal during a predetermined period during which the second state / pulse lasts, access is reached. If against the device that mentioned above dominant signal or receives the impulse, which is the indication of the fact represents that another transceiver access has received or is just at the point where it has access to the circuit attained, the first mentioned returns Device in his listening position back. As soon as access is achieved, the corresponding transceiver has the option of the Circuit information to the other transmitting and receiving devices, to the main unit (controlling device) or to another device together with control data. The transceiver, This is about the Circuit a dominant acknowledgment signal (acknowledgment sign), d. H. a zero, from the corresponding device or from a device that has the Information receives.
  • High speed transmission over long distances using systems that comply with the data transfer regulation work is already known and can be based on circuit access that mentioned in the introduction Access function - bitwise Decision - based. A method of solution the problem of collisions on the data transmission media or a Data transmission circuit for the Serial data transmission, z. As an electrical two-wire bus, is the above-mentioned decision function. A well-known example of this is the system that works according to the CAN data transfer protocol, that of the German company "ROBERT BOSCH GmbH " has been.
  • In In industry, it is often the case that the transceivers spatially (psychologically) grouped and that these groups are at great distances from each other are located. In this connection, some meters are considered short distances and a few hundred meters to a kilometer and more than long distances Understood.
  • One another well-known procedure for regulating access to the data transmission medium in data transmission lines is the token passing. The device, which in this case has the token, also has access to the medium or to the circuit. After the transfer the token is free and other devices can access the mentioned token gain. There are also other methods for assigning access to a transmission medium. In this regard, you can the slotted bus, the time division, etc. are mentioned, the average Well known to those skilled in the art.
  • A another well-known structure for solving problems related with the data transfer between groups over size Distances from each other is the so-called bus bridge function. It is characterized by the fact that it is in every group a machine probably with the local Basic group as well as with a corresponding device in the connected to another group. The bridge device collects information the local Bus, which should go to the other bus, and transmits it to the bridge device in the another group that distributes the information to the local bus.
  • The US 4,583,088 describes a system for transmitting messages consisting of a plurality of units each having a central processing unit, a memory, a communication control unit and a switch driver unit for receiving and transmitting electrically decrypted messages, wherein a transmission breaker is provided which is arranged so that when the transmission breaker is open no messages can be transmitted and the transmission breaker is controlled by the central processing unit.
  • There is a need for the ability to further develop the CAN system protocol mentioned above. The known system means that the data transmission speed depends on the distance between the transceivers that are farthest from each other. This is due to the fact that all intercommunicating transceivers must delay the determination of the value of the impressed signal together with the access and acknowledgment functions so that the signal in question has time to reach the farthest transmitting and receiving stations Propagate and return to the receiving device, resulting in effects that limit the data transfer rate. The invention aims, inter alia, to solve this problem.
  • In the known process for confirmation (receipt) the transmitted Message, the transmitter sends out a recessive signal after the Data and a test code transmitted to the appropriate recipient have been. If the latter is the receiver that the Has processed the message correctly, sends the candidate in question receiver a dominating signal on the circuit and the transmitter knows that the message went through correctly. When a transceiver receives the message interpreted as incorrect, the above-mentioned device sends an error signal consisting from dominant signals, from. The invention is in this circuit can be used and solve also this problem.
  • The Data transmission speed should even over longer distances can be maintained and should not affect the total length of the transmission link limited be. The invention solves also this problem.
  • The known decision-making in terms of access to the transmission medium and the confirmation procedures, which have been described so far, and in the known CAN system There are many advantages that it is desirable and desirable to be able to obtain is required. By the invention it is possible the basic structure of the CAN system (protocol) to use and the above-mentioned shortcomings, the in that the bandwidth in transmissions over one become bigger Distance reduced, still overcome.
  • The Invention ensures that transmitters and receivers, which are set to an incorrect frequency, no access to receive this connection and prevented from connecting between the devices to impair which are tuned to the right frequency.
  • In addition, will it possible be that main features are built into the system, and that higher Logs are created so that they transmitted incorrectly Can correct messages.
  • The Invention will also allow that Items for the systems in question from different manufacturers can be produced. Thus, the system designers will be able to system structure and system functions, regardless of the manufacturers of the Items for the ones mentioned above Transceivers, Branching points, printed circuit boards, etc.
  • The Invention proposes Among other things, that a group consisting of at least two transmitting devices and two receivers, an exclusive access to the transmission medium is assigned while all other transmitters and receivers can listen. On this way is the mentioned bandwidth only on the distance in the area of the group in question limited, considered as a major group with subsets of active transceivers can be. Different devices within the main group Access to the medium or the circuit by decision (arbitration) gain. The members of the group equipment to lead the signaling via confirmation (acknowledgment) or error, based on whether the sender and receiver are using the Message interpreted as correct or incorrect. Such a thing activated group is referred to herein as an active group. Other Main groups come to the interpretation of the same message and to carry out the same exam, but they do not send an error signal across the medium when they are interpret the message as incorrect. The last mentioned main groups are classified here as passive main groups. If any Device in the passive main groups interpreted a message as incorrect, so may in one embodiment this Information on a higher Protocol level, d. H. the transmitting and receiving device transmits no error signal over the transmission medium if the error relates to an earlier passive period, when it stopped had to be active. This embodiment The inventive concept offers the use of a variety of methods to, who per se for the error evaluation at a higher Protocol level, and the optimal application of these methods depends on the System requirements.
  • In one embodiment, the problems mentioned in the introduction are solved, inter alia, by the use of a bridge device function in which the bus in question is jointly available for both subgroups involved. In each main group, one device has a higher rank than the other devices and can prevent them from sending over the bus. Such a higher-level device is thus provided with a controlling function or designed as a main device. Due to the fact that every main unit Alternatively, if its group permits transmission, the connection may be maintained at a bandwidth determined by the distance between the most distant transceivers within a main group. In one embodiment, the main unit commands its main group to enter a passive switch position by a special message transmitted over the bus. As soon as the main unit in the other main group receives this message, it instructs its main group to take an active position. In order to be able to transmit the message about the transition from a passive to an active switch position, the main unit is equipped with two transceivers, one of which has the task of checking whether the message is from the other Device appears correctly on the medium. The other device then acknowledges the message in the conventional manner.
  • In an embodiment can all devices like that be construed that they are only within a main group with each other get in contact. In this case, the devices on the Ability to, too to change the passive switching position described above. In certain make It can also be an advantage if the above mentioned device, as soon as it enters the active Switch position changes, indicating exactly whether it was passive during the previous one State has interpreted any message as incorrect. Only the main units need a higher level error analysis log to handle cases where a group has interpreted a message as correct while the other group interpreted them as incorrect. If each group has one Error evaluation log and media access log (eg from the Type token passing), are not main devices (controlling devices) required.
  • In a further embodiment will the above mentioned Bridge device function used. In today's applications, eg. In the CAN system protocol, is the transmission speed limited by the distance, notwithstanding the fact that it is a simple matter to ensure that a message collision can not occur, as provided will that the acknowledgment procedure (the confirmation process) within a certain Period takes place. The invention offers the solution, the bridge devices with two transmitters and receivers equip. These devices are close together (a few centimeters), and the delay between these devices is no longer due to the spatial Distance, but dominated by internal delays in the Are essentially computational nature. With good cable quality and standard components, the are intended for this purpose, for. B. Philips 82C200 CAN CONTROLLER, it is possible the message in accordance to transmit with the CAN protocol, where a bit transfer rate of 1.6 Mhz over Distances far beyond a kilometer, possible is. This fact increases the transmission bandwidth essential. Starting from current Process engineering is at about 50 kHz at a distance from 1 km. Thus increased the bandwidth is a factor of 32.
  • In accordance with the above, the feature which in principle can be regarded as characteristic of the new arrangement is, inter alia, that in the said system only the fixed or selected transmitters and receivers lying on a track are, above all, considerably shorter is to be activated as the total length of the circuit in order to be able to transmit in accordance with one of the following alternatives or with both:
    • Either the dominant signals or pulses are influenced both by the access functions and by the confirmation functions,
    • - or the dominant signal or signals are only affected by the confirmation function or the confirmation functions.
  • Other Transmitters and receivers included in the system are prevented from to transmit said dominant signal or signals but are arranged so that they on the bus circuit a Mithörschaltstellung can take.
  • A currently offered embodiment an arrangement that has the features that are characteristic for the Invention are described below with reference to the attached Drawings that represent:
  • 1 a circuit diagram of a bus circuit and transceivers that are connected in groups with this bus circuit,
  • 2 also in the form of a circuit diagram and on an enlarged scale parts of the system according to 1 .
  • 3 in the form of a circuit diagram the transmission by means of a single optical transmission path,
  • 4 the application of the invention to a bridge circuit, and
  • 5 - 10 in the form of block diagrams and pulse schemes, the principle of the bit structure of the decision system, etc.
  • There It is the object of the present invention, the per se known CAN telecommunication system considerably To improve, the basic functions that make up this System is operated, discussed here become.
  • The System is based on a serial electrical two-wire communication bus (C-bus). A transmitted Zero dominates over a transmitted one. For NRZ procedures (Non-return-to-zero recording) d. H. if different identical characters are transmitted, the Level on the bus not changed. Under normal conditions, a maximum of five identical characters transmitted in a row. If the transferred Message more than five contains identical characters in a row, the sender and receiving device an opposite extra character. If no transfer takes place, the bus represents a continuous transmission of ones. Once a device is transferred would like to, it counts first a series of ones, d. H. the bus is free, and then transfers a zero, the so-called frame start. All devices that are currently intended have a transmission to begin to add Add this zero and bring in this way to synchronization to this character pattern. All devices read the bus, d. H. also those who are transferring. If a station transmits a one, but Reading a zero, he draws the conclusion that a participant with a higher one priority at the same time a transmission performs. That's the only way it stays a transmitter left. Once the decision box or stage is over, the sender indicates how many bytes are transferred becomes. After they transfer have been entered, a checksum occurs on. All recipients calculate the corresponding sums in parallel. After the transmitter transfer the checksum has, he transmits one One. All recipients, which have reached the same sum, transmit a zero. The transmitter then understands that at least one participant listened in and understood has that nobody thinks that it was incorrect. In such a case it would have sent an error frame consisting of six zeros, d. H. opposite usually in relation to five identical characters in a row. From the above, it is clear that an outgoing character must remain as long as a send and a receiving set needs the sign over to send out the bus so that the sign on the bus farthest remote transceiver in the system, multiplied two times, transfer becomes. To ensure, that the bus is free, d. H. to make a decision unnecessary, is z. Simply a timeline-based protocol or a chaining protocol (or protocol of a serial priority circuit) used. After the above, the problem is the confirmatory method, namely, that the confirmation zero the Transmitter will reach from the farthest device while the Transmitter still transmits a one. The Invention solves this issue by keeping the transceivers in groups will send out zeros. The fact that the confirmation zero not transferred between groups and that the decision between groups does not take place, means connecting between groups on a single optical link or transmitted by radio can be. A preference of the method in accordance with the last mentioned The principle is that so little is changed in the protocol. The actual encoding of the content of the message must be at all not changed be, and the larger part of the CAN protocol is carried out in the normal way z. B. the different control functions. In the text above It has been assumed that all devices with the same bit rate transmitted. It will be easy to see from the above that a mistake occurs when any device transmits at a different bit rate. To the Example, if any device a bit transfer speed which is less than one-sixth the speed of the other, a zero transmitted from this device will be the other one be interpreted as an error frame. This situation will prevented by the invention, due to the fact that no branch point in a group is allowed, one To transmit zero, as long as he does not receive a clear signal from his main unit Has. When a device is on the wrong bit transfer speed has never been set, it never gets messages from the main unit can receive. The invention underlying spatial arrangement can be used to solve the Problems in agreement with the last mentioned Consequence can only be used if the distances no Pose a problem.
  • The invention enables the CAN protocol to have a higher transmission speed than the speed indicated by the detailed description of the protocol, and it prevents CAN devices with an incorrectly set bit transmission speed from interfering with transmission on those devices where the bit transmission speed has been set correctly is. Delays in commonly occurring CAN connections are 5 nanoseconds per meter. A typical value for a delay in a CAN controller is currently 10 ns, which corresponds to a two-meter connection. The delay in the bus driver circuit is 80 ns, which corresponds to 16 meters. In the invention and a point-to-point connection, only the delay in the CAN control unit is measured, since the distance between the transmitting and receiving device 1 and 2 only about one centimeter and the confirmation before the driver can take place. Ie. a bit transmission speed of 100 MHz would have to be possible from the point of view of delay. At present, "Philips" controllers are designed for 1.6Mhz, but it is technically possible to make much faster chips.
  • In 1 is a bus circuit with 1 designated. With the circuit 1 are the main groups consisting of transceivers 2 and 3 included in the subgroups 4 . 5 . 6 such as 7 . 8th . 9 . 10 are divided, connected. According to the invention, the main groups are activated individually while the others or other main groups remain passive. The number of subgroups may vary and each subgroup may include one or more transceivers.
  • Corresponding 2 The bus circuit can be made up of a two-wire circuit with the branches 1a and 1b be assembled. The recipient 4 ' serves as the main unit (compare the unit in 1 ). The main unit is equipped with two transceivers 4a . 4b and a data control unit 11 which consists of a microcontroller. The main unit 7 ' (the device 7 in 1 ) is the same design as the main unit 4 ' , The devices that do not have the function of a main device in the corresponding main group can have a configuration like the device 8th' have, ie only a transmitting and receiving device with a connected microcontroller 12 , The mentioned devices 4 - 10 . 4 ' . 7 ' and 8th' have a structure that is known per se, and in this regard, reference may be made to the structure of the above-discussed CAN system.
  • 3 shows the main groups 13 and 14 where only the main unit 15 in the group 13 will be shown. The bus circuit is marked here 16 , In the group 14 are the main device 17 and the device 18 have been shown, see above. The bus circuit is in this case with 19 have been designated. The bus circuits are via an optical fiber connection 20 interconnected, which may consist of only one fiber connection in the illustrated example. Between the bus circuits 16 . 19 and the mentioned glass fiber connection 20 are the matching units and possible buffer devices with 21 and 22 designated.
  • 4 provides a bridge bus system with the connected devices 23 and 24 The latter devices may consist of printed circuit boards, which are known per se, and in each case via the micro-control units 25 and 26 feature. Each device is each with its main group 27 and 28 connected via normal bus circuits (CAN bus switching connections). The bridge bus circuit is with 31 characterized. The connection to the CAN circuits takes place via a transmitting and receiving device 32 and the connection to the bridge bus circuit via the transmitting and receiving devices 33 and 34 , One of the last-mentioned transceivers has the task of recognizing the candidate acknowledgment signal in accordance with the above.
  • 5 represents the principle of bitwise decision. In this case, the corresponding transmitting and receiving device with each 35 and 36 as well as the circuit with 37 characterized. Since the principle is known per se, it will not be described here in any detail.
  • In an embodiment has the main unit only one transmitting and receiving module device. As often as the main unit its Transmits message and thus causes that the devices must take the active mode, the main unit receives none Confirmation. The message is then retransmitted according to the CAN protocol up to about ten times. Once a device in the group the active position it will issue a confirmation signal. If any device in this case is able, within the retransmission time the active mode, it is possible with only one Transmitter and receiver provided main unit to get along, thus a solution according to the invention forms.
  • With regard to the confirmation procedure, the 6 and 7 mentioned. branching point 1 (= Device 1 ) sends a message that has just ended. The circuit when the device 1 sends a one while the branch point 2 (the device 2 ) is acknowledged with a zero, as well as the following one sent by both. The signal levels on the bus near the branch point or device 2 are displayed below. In 7 the distance is great, and we can see that the branching point or the device 2 the signals detected later, as if the branch point 1 transmits the mentioned signals. Once branch point 1 expects that branch point 2 its one overwrites reads branch point 2 the last character. If device 2 then send out its zero, it comes to the branch point 1 too late. The device 1 has the perception that the zero has never arrived, whereas the expected subsequent one is instead zero, ie an error.
  • In the 8th - 10 represent the various components and functions:
  • * A1
    Storage
    * A2
    Information processing (eg Nec, CPU (central processing unit), Nec V25 + CPU).
    * A3
    Communication control unit (eg Philips 82C200).
    * A4
    Circuit driver unit (eg Philips 82C250).
    * A5
    Enabled Disabled Transmission (= Contact).
    * A6
    Electrically decrypted message (reception).
    * A7
    Electrically decrypted message (send).
    * A8
    Electrically encrypted message (eg ISO 11898).
    * A9
    Built-in address, data and control bus.
    * A10
    Enabled Disabled transmission.
  • 8th represents the principle structure of the local system. 9 indicates when transmission is enabled, and 10 indicates when the transmissions are interrupted. 9 shows the system function after the branch point (the device) has received the message that activates the transmission from the branch point. In 10 the branch point or device has received the message when the transmission from the branch point or device is interrupted (or vice versa).
  • A system can according to 8th consist of different branch points. These branch points are interconnected via a communication link (bus or other location relationship). When the system is started up, the central processing unit (CPU) scans the memory. The latter contains inter alia information about the position of the transmission breaker, see 8th , Block A5. (The contact is either closed or open.) A closed transfer breaker means that the module can transfer messages. An open transfer breaker means that the module is unable to transfer messages. Regardless of the position of the transmission breaker, the module can receive messages on all characters. Once cranking is complete, there is at least one branch point with a closed transfer breaker. If there are some branch points with a closed transfer breaker, there is more information in memory that determines who in the system is the main unit. The tasks of the master apparatus include, among other things, the assignment of the transmission authority and the refusal of transmission for individual branch points or groups of branch points. Once a branch point receives a transmission permission message, the central processing unit (CPU) closes its transmission interrupts, see 9 , Block A5 and A10. Messages about a transmission authorization and transmission refusal can be combined in one and the same message in order, for. B. to grant the authorization to transmit a certain number of messages or a certain number of messages of a certain type, or to approve the transmission at a certain time during a time channel, etc. The transmission permission or refusal may also be a combination of the above-mentioned variations.
  • The Restricted invention not on the example given above embodiment, but may instead of which within the attached claims and the inventive concept be modified.

Claims (8)

  1. A system for receiving and transmitting messages composed of digital pulses according to a transmission protocol, comprising a central processing unit (A2), a memory (A1) cooperating with a communication control unit (A3) having a first connection for receiving an electrically decrypted one Message (A6) and a second connection for transmitting an electrically decrypted message (A7) and a contact (A5) controlled by the processing unit (A2), the first and the second connection being connected to the communication control unit (A3) and a third connection (A9) is connected to the communication control unit (A3), and wherein the central processing unit (A2) drives the contact (A5) in the second connection (A7) to assume a state permitting or prohibiting transmission , characterized in that a CAN protocol of the type ISO 11898 is used, u and the communication control unit (A3) transmits and receives electrically coded pulses in accordance with this protocol via zeros with a first and ones with a second pulse level via a circuit driver unit (A4), the zeroes being dominant and the ones being recessive and the first pulse level is dominated over the second pulse level, and a pulse of binary flags is composed on the basis of the time and the pulse levels, the communication control unit (A3) detecting incoming messages / information on the first and third links (A6, A9) and using the protocol detects incorrectly and correctly received messages and compiles and prepares or transmits error frames, which consist of six consecutive dominating marks are combined according to each erroneously received message, and a confirmation signal in the form of a dominant flag is generated when a correctly received message has been received, and wherein the reception via the first connection (A6) and the processing in the communication control unit (A3) are independent Is the state of contact (A5) permitting or inhibiting transmission, and wherein the central processing unit (A2) drives the contact (A5) so that when it is placed in a state that does not permit transmission, it is prohibited occurring error frames and confirmation signals can be transmitted.
  2. System according to claim 1, characterized in that News independently from a position of the transmission breaker (A5) are always receivable.
  3. System according to claim 1 or 2, characterized that from the units of the system messages for transmission authorization and transfer refusal are receivable.
  4. System according to claim 3, characterized in that the messages are combined in one and the same message.
  5. System according to one of claims 1 to 4, characterized that only a certain number of messages are transferable.
  6. System according to claim 5, characterized in that only a certain number of messages of a certain type transferable are.
  7. System according to one of claims 1 to 6, characterized that messages only transferable at a certain time during a time channel are.
  8. System according to one of claims 1 to 7, characterized there is information in the memory (A1) which determines Which of the units in the system is a main unit.
DE19549815A 1994-04-18 1995-04-13 Serial bus connection equipment eliminating functional interference - couples main transmitter and receiver units divided into sub-groups enabling high speed communication Expired - Lifetime DE19549815B4 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
SE9401305 1994-04-18
SE9401305A SE501984C2 (en) 1994-04-18 1994-04-18 Serial bus connection equipment eliminating functional interference - couples main transmitter and receiver units divided into sub-groups enabling high speed communication
DE1995114696 DE19514696B4 (en) 1994-04-18 1995-04-13 A system for eliminating interference or for enabling high-speed transmission in a serial bus circuit and transceivers connected to the latter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE1995114696 DE19514696B4 (en) 1994-04-18 1995-04-13 A system for eliminating interference or for enabling high-speed transmission in a serial bus circuit and transceivers connected to the latter

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102009055797A1 (en) * 2009-11-25 2011-05-26 Valeo Schalter Und Sensoren Gmbh Circuit arrangement and a control unit for safety-related functions
WO2011089380A1 (en) * 2010-01-22 2011-07-28 Simm Tronic Limited Method and apparatus for searching for values of one or more parameters and related devices

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4583088A (en) * 1982-06-15 1986-04-15 International Business Machines Corp. Method and apparatus for controlling access to a communication network

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4583088A (en) * 1982-06-15 1986-04-15 International Business Machines Corp. Method and apparatus for controlling access to a communication network

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102009055797A1 (en) * 2009-11-25 2011-05-26 Valeo Schalter Und Sensoren Gmbh Circuit arrangement and a control unit for safety-related functions
WO2011089380A1 (en) * 2010-01-22 2011-07-28 Simm Tronic Limited Method and apparatus for searching for values of one or more parameters and related devices

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