CAN Patents

This list is by no means complete. Also note that it currently contains US patents only.

1. U.S. Patent 4,841,450, Arrangement comprising a system providing movement, processing and/or production
2. U.S. Patent 4,887,262, Single-channel bus system for multi-master use with bit cell synchronization, and master station comprising a bit cell synchronization element suitable for this purpose
3. U.S. Patent 5,323,385, Serial bus communication method in a refrigeration system
4. U.S. Patent 5,383,116, Device for controlling a member in a system
5. U.S. Patent 5,444,626, Control system for calculating parameter control values in repetitive control processes
6. U.S. Patent 5,448,180, Transmitter end stage
7. U.S. Patent 5,448,561, Method & apparatus for data exchange in data processing installations
8. U.S. Patent 5,452,201, Industrial controller with highly distributed processing
9. U.S. Patent 5,469,150, Sensor actuator bus system
10. U.S. Patent 5,502,818, Procedure for the determination of message identification in the data transmission network of an elevator system
11. U.S. Patent 5,539,778, Reception comparator
12. U.S. Patent 5,551,053, System and Method for assigning addresses to I/O devices in a control network and for verifying the assigned address of the devices
13. U.S. Patent 5,574,848, CAN interface selecting one of two distinct fault recovery method after counting a predetermined number of recessive bits or good can frames
14. U.S. Patent 5,596,437, X-ray device
15. U.S. Patent 5,600,782, CAN interface with enhanced fault confinement
16. U.S. Patent 5,617,282, Data communication system
17. U.S. Patent 6,151,298, Electronic bus system

U.S. Patent No. 4,841,450

Arrangement comprising a system providing movement, processing and/or production
Inventors: Fredriksson; Lars-Berno (Kinna, SE).

Abstract

In a system for the performance of a plurality of functions, each of the functions is allocated its own function control member comprising a microprocessor with the associated peripheral equipment, and one or more actuating devices. Each control member is capable of providing the control for functions of two or more types, and the different control members are mutually interchangeable. The control members are connected in one or more first wiring loops, each of which is connected to a main computer. The signal transmission in the first loop is performed digitally and in series. The transmission of the signals includes first signals emanating from a basic or operative program in the main computer, said first signals are transmitted during a start-up phase for the system and comprising for each control member information in respect of its adjustment in relation to a function control which is applicable to the type of function and/or the variation in the type of function effected by the control member during an operating phase which follows the start-up phase. The signal transmission also includes second signals emanating from a user program entered in the main computer, which second signals are transmitted in a cyclical fashion and which contain continuous information for each microprocessor relating to the manner in which the function served by the microprocessor is to be controlled. The actuating means are supplied with energy via one or more second wiring loops, each of which is connected to an energy source.

U.S. Patent No. 4,887,262

Single-channel bus system for multi-master use with bit cell synchronization, and master station comprising a bit cell synchronization element suitable for this purpose
Inventors: van Veldhuizen; Evert D. (Eindhoven, NL).
Assignee: U.S. Philips Corporation (New York, NY).

Abstract

Messages consisting of an arbitration field followed by a data field circulate in a single-channel bus system. The stations comprise a storage element for an intended delay time between a locally formed signal transition and a resultant detectable signal transition. The stations also comprise a continuous sequencer for the successive bit cells. When a signal transition is detected, the sequencers are loaded with the position of the storage element, so that they are synchronized. In the case of a transmission operation, the delay is measured, so as to update the contents of the storage element.

U.S. Patent No. 5,323,385

Serial bus communication method in a refrigeration system
Inventors: Jurewicz; Romuald M. (St. Louis Park, MN); McCormack; Michael D. (Robbinsdale, MN); Johnson; Dannis R. (Savage, MN).
Assignee: Thermo King Corporation (Minneapolis, MN).

Abstract

A method of communication in a refrigeration system, between communication nodes connected to a serial data bus using Controller Area Network protocol (CAN) having a message frame format which includes a data field. The method includes converting a byte of the data field of each message frame to a permanent data descriptor expansion byte (DEB). In at least the first frame of a message a specific bit of the DEB is set to a first logic level to indicate a control frame, and information descriptive of the whole message is loaded into the remaining bits of the DEB, and data field. In each remaining frame of a message following a control frame, or control frames, the specific bit is set to a second logic level, to indicate a data frame. A block of data is loaded into the data field of each data frame, and index information specific to the associated block of data is loaded into the remaining bits of the DEB.

U.S. Patent No. 5,383,116

Device for controlling a member in a system
Inventors: Lennartsson; Kent (Malmo, SE).
Assignee: Kvaser Consultant AB (Kinnahult, SE).

Abstract

An apparatus or manufacturing system in which a first member executes a desired function or action which is controllable as a function of at least one parameter characteristic for a second member is provided. A first detector detects signals corresponding to values of the at least one parameter of the second member. At least one transmitter receives the detected signals and assigns coded/numbered messages for each value of the parameter. The apparatus further includes at least one receiver with a control module for controlling the desired action of the first member. The signal transmission between the transmitter and the receiver occurs over a connection bus and the signals are transmitted in the form of the coded/numbered messages in a predetermined order, with well defined transmission times between the first detector and the transmitter and between the transmitter and the receiver. A control unit controls operation of the receiver module and send thereto at least information regarding a desired parameter value at which a corresponding desired function or action is to be executed by the first member, or a desired message number to be selected. The receiver obtains the requested desired message number or, based on the desired parameter value and the time information for the desired action or function of the first member selects itself and receives a corresponding message number containing the parameter value. Based on the message number the receiver generates an activation signal for the first member.

U.S. Patent No. 5,444,626

Control system for calculating parameter control values in repetitive control processes
Inventors: Schenk; Joachim (Hemmingen, DE).
Assignee: Robert Bosch GmbH (Stuttgart, DE).

Abstract

It is known for a central electronic control unit in a motor vehicle to exchange data through a serial data bus with other control units, e.g. those for fuel injection, ignition timing, and braking. Prior art systems transmitted these data automatically, regardless of whether all these parameters were relevant to the actual operating state of the vehicle, thereby resulting in heavy loading of the serial bus. The present invention determines which parameters are irrelevant to the current operating state and suppresses transmission, or even calculation, of these irrelevant parameters.

U.S. Patent No. 5,448,180

Transmitter end stage
Inventors: Kienzler; Rainer, Reutlingen, Federal Republic of Germany; Fleischer; Ulrich, Pliezhausen, Federal Republic of Germany; Elbracht; Berthold, Reutlingen, Federal Republic of Germany
Assignees: Robert Bosch GmbH, Stuttgart, Federal Republic of Germany

Abstract

A transmitter end stage for a data transmission system comprising at least one control unit and data transmission lines, especially for a CAN bus system having at least one CAN controller and one CAN bus (CB) is proposed, characterized by the fact that the individual circuit elements of transmitter end stage 18 are integrated monolithically. As a result of the special layout and its circuit-design arrangement of the individual elements (3, 5; R1, D1, T1; R2, D2, T2; D10, D20) of the transmitter end stage, the effects of malfunctions, for example of short circuits of the data lines to ground or to the supply voltages, are reduced to a minimum. As a result of the special choice of pre-drivers (3, 5), minimum delay times are achieved, so that signals can be transmitted at a higher data rate.

First Claim

1. In a driver associated with a data line of a bus system, a monolithically integrated end-stage circuit comprising:
   1. a switching transistor, said switching transistor
      1. electrically coupled between said data line and a supply voltage,
      2. controlled by a control signal;
   2. a resistor, said resistor
      1. connected in series with said switching transistor,
      2. connected to said data line,
      3. formed lying in a tub of said monolithically integrated circuit;
   3. a first diode, said first diode
      1. including an anode coupled with said supply voltage,
      2. including a cathode coupled with said tub of said resistor; and
   4. a second diode, said second diode connected in series with said switching transistor.

U.S. Patent No. 5,448,561

Method & apparatus for data exchange in data processing installations
Inventors: Kaiser; Karl-Heinz (Tamm, DE); Lohner; Herbert (Friolzheim, DE); Mathony; Hans-Joerg (Stuttgart-Botnang, DE); Unruh; Jan (Vaikingen, DE); Zurmuehl; Uwe (Hildesheim, DE); Brunke; Udo (Diekholzen, DE); Glasser; Juergen (Hildesheim, DE); Linne; Olaf (Bockenem, DE).
Assignee: Robert Bosch GmbH (Stuttgart, DE).

Abstract

An improved method for exchange of data in data processing installations, especially Controller Areas Networks (CAN), permits acknowledged and segmented transmission of data strings, of arbitrarily long length, between at least two stations in the network or other data processing installation. The method includes the transmission of the messages associated with the data by means of frames; the frames contain a header field and a data field. In the event of contention between multiple stations of the data processing installation for access to the bus connection, which frame has priority is determined by evaluating the respective header fields. In the data field of the frame, there is a control information field (58, 95) containing a message code which serves to identify the message type. The message codes distinguish among activation messages (AR, AC), data messages (DT), and acknowledgement (AK) messages. This permits transmission of data strings, of limited length, with acknowledgement. Further, the control information fields (58, 95) of certain messages contain a sequence number, a receiver status code, a message end code, and a code specifying how many data bytes are being transmitted in the frame. With this additional information, data strings of arbitrarily long length may be transmitted as segments. The receipt of the individual partial messages is confirmed by sending back an acknowledgment in each case.

U.S. Patent No. 5,452,201

Industrial controller with highly distributed processing
Inventors: Pieronek; Donald S. (Waukesha County, WI); Hodorowski; John J. (Milwaukee County, WI).
Assignee: Allen-Bradley Company, Inc. (Milwaukee, WI).

Abstract

A highly distributed industrial control system employs a number of separate control modules communicating together on ashared communications medium. Each module emulates one or more basic electrical parts having electrical terminals, such as switches and relays, and transmits production messages indicating the state of the parts, such as conducting current or not. A connection list for each part in each control module defines message identifiers of other parts whose production messages are received by the control module and interpreted as current flow to one or more of its parts. The control system is programmed by generating a schematic on a programming terminal showing connections of terminals on symbols of the parts such as would represent actual wiring of the emulated parts. This schematic is analyzed to determine the immediate upstream neighbors of each part and the message identifiers of those parts in the control modules form the connection lists. In this way the program is divided to run concurrently on the various modules.

U.S. Patent No. 5,469,150

Sensor actuator bus system
Inventors: Sitte; Hans J., Freeport, IL
Assignees: Honeywell Inc., Minneapolis, MN

Abstract

A four-wire bus is provided with a two-wire power bus and a two-wire signal bus and a plurality of sensors and actuators attached to both two-wire busses. A modification is provided to the standard CAN protocol developed and provided by Robert Bosch GmbH, in which the standard CAN header, of a data packet is modified to incorporate a shortened device identifier priority. By shortening the identifier field of the CAN header three bits are made available for use as a short form protocol data unit which can be used to contain binary information representing both the change of status of an identified device and the current status of the device. The same three-bit PDU can be used to acknowledge receipt of the change of status information. In order to retain all of the beneficial capabilities of the standard CAN protocol, the three-bit short form PDU can also be used to identify the use of additional bytes of a data field so that a device can take advantage of the more complex capabilities of the standard CAN protocol. However, in situations where a mere change of status report is sufficient, the present invention reduces the length of a message from a minimum of three bytes to a length of two bytes to obtain the significant benefits of increased speed of message transmission.

First Claim

The embodiments of the invention in which an exclusive property or right is claimed are defined as follows:

1. A sensor actuator bus, comprising:

* a four-wire bus comprising a two-wire power bus and a two-wire communication bus;
* a plurality of sensors, each of said sensors being connected to said two-wire power bus and to said two-wire communications bus, said two-wire power bus and said two-wire communications bus being disposed in a common cable, each of said plurality of sensors comprising a means for formulating a data packet containing information representing a status of said sensor associated with said formulating means and a means for transmitting said data packet on said two-wire communication bus, each of said sensors being connected in signal communication with said two-wire communications bus and connected in electrical communication with said two-wire power bus, said transmitting means being connected in signal communication with said formulating means, said data packet comprising a direction bit, seven priority bits for identifying an associated sensor and three message bits, said data packet being arranged in conformance with a Controller Area Network protocol system.

U.S. Patent No. 5,502,818

Procedure for the determination of message identification in the data transmission network of an elevator system
Inventors: Lamberg; Lauri, Hyvinkaa, Finland
Assignees:Kone Elevator GmbH, Baar, Switzerland

Abstract

A procedure is disclosed for determining the message identifiers in a control area network CAN data transmission network of an elevator system where message identifiers are used in the transmission of messages. Each node in the network monitors the data transmissions in the network and stores the other message identifiers in use by the other nodes. When selecting a message identifier, the node makes use of a random number to select an unused identifier from an identifier table.

First Claim

1. A method for determining message identifiers in a controller area network (CAN) of an elevator system having a plurality of nodes, wherein a predetermined number of predetermined message identifiers are used in the transmission of messages between nodes of said network, said method being implemented simultaneously by each node in the network and comprising the steps of:

• monitoring data transmissions taking place in the network, and storing those message identifiers being used by other nodes of the network, and storing a respective message state of each message identifier being used by other nodes of the network;
• selecting a message identifier, from among said predetermined message identifiers, that is not among those message identifiers being used by other nodes of the network, and waiting for a first delay period, the duration of said first delay period being equal to a predetermined delay period plus a random delay period;
• following expiry of the first delay period, performing an availability test by sending an "I propose" message containing the selected message identifier and a random number into the network, the random delay period preventing simultaneous transmission of "I propose" messages from each node in the network, and the random number ensuring that a detectable collision occurs even if "I propose" messages are transmitted simultaneously and waiting for a second period of time;
• if no cancellation reply is received from another node and a message collision is not detected before expiry of the second delay period, sending an "In use" message containing the selected message identifier into the network, and waiting for a third delay period;
• if no cancellation reply is received from another node and a message collision is not detected before expiry of the third delay period, sending an "I am using" message containing the selected message identifier into the network;•wherein said "I propose", "In use" and "I am using" messages constitute messages having progressively higher message states and wherein, following the transmission of each said "I propose", "In use", and "I am using" messages, a node sends a cancellation message to another node if it receives, from the other node, a message having the same message identifier and any one of an equal or a lower message state; and
• if, before the expiry of each of the first and second delay periods, no message is received from another node of the network whose respective message state is either "I propose" or "In use", reducing said stored message state of the message identifier associated with said other nodes.

U.S. Patent No. 5,539,778

Reception comparator
Inventors: Kienzler; Rainer, Reutlingen, Federal Republic of Germany; Fleischer; Ulrich, Pliezhausen, Federal Republic of Germany; Elbracht; Berthold, Reutlingen, Federal Republic of Germany;
Assignees: Robert Bosch GmbH, Stuttgart, Federal Republic of Germany

Abstract

A receiving comparator for a data-transmission system comprising at least one control unit and data-transmission lines, in particular for at least one Controller Area Network (CAN) controller and one CAN bus system having a CAN bus (CB) is proposed, which is distinguished by the feature that the individual circuit elements are monolithically integrated. By generating a switching threshold which is independent of the operating voltage and temperature with the aid of a current source (IS), one prevents the CAN bus potentials from being asymmetrically influenced. The arrangement guarantees a processing of digital signals with a high data rate, whereby the input common-mode range extends up to above the supply voltage and to below ground.

First Claim

1. A receiving comparator for a data-transmission system having at least one control unit and at least one data-transmission line, the receiving comparator comprising:

• a signal conditioning device having an input for connection to the at least one data-transmission line, the signal conditioning device including an input divider for adjusting input potentials from the at least one data-transmission line;
• a comparator circuit, coupled to the signal conditioning device and having a threshold-value generating device, the input divider including a reference-voltage source whose potential is selected to provide input signals to the comparator circuit which lie within a supply band;
• a signal-amplifier stage coupled to the comparator circuit; and an output stage coupled to the signal-amplifier stage; wherein the signal conditioning device, comparator circuit, signal amplifier stage, and output stage are monolithically integrated.

U.S. Patent No. 5,551,053

System and Method for assigning addresses to I/O devices in a control network and for verifying the assigned address of the devices
Inventors: Nadolski; Gregory L., Brookfield, WI
Assignees: Eaton Corporation, Cleveland, OH

Abstract

A method and system is provided for assigning addresses to input/output (I/O) devices in a control network, and for verifying addresses assigned to the I/O devices. The system comprises a logic controller providing memory into which a connectivity map may be programmed. The connectivity map defines a specific expected address for each I/O device in the system. The logic controller further provides an external controller bus and logic for downloading the connectivity map  to an I/O bus manager connected to the logic controller via the external controller bus. The I/O bus manager provides logic for assigning the specific addresses to the I/O devices. Network nodes connect the I/O bus manager to I/O cluster units in the system, each network node including a multiplexer for multiplexing output signals from the I/O bus manager and a demultiplexer for demultiplexing input signals from the I/O cluster units, the multiplexing/demultiplexing functions provided by a controller area network (CAN) integrated circuit. Each I/O cluster unit includes a multiplexer for multiplexing input signals from the I/O devices and a demultiplexer for demultiplexing output signals from its associated network node, the multiplexing/ demultiplexing functions again provided by a controller area network (CAN) integrated circuit. Each I/O cluster unit provides means for manually requesting address assignments and a visual indication of addresses so assigned. Each I/O cluster unit also provides means to manually reject the address assigned to it by the I/O bus manager if the assigned address is not the expected address for the I/O cluster processor defined in the connectivity map.

U.S. Patent No. 5,574,848

Can interface selecting one of two distinct fault recovery method after counting a predetermined number of recessive bits or good can frames
Inventors: Thomson; Thomas W., Santa Cruz, CA
Assignees: National Semiconductor Corporation, Santa Clara, CA

Abstract

A CAN node with a CAN protocol controller device reconnects to a CAN bus from the node's busoff state only after the node has successfully decoded a plurality of good messages from other devices on the CAN bus. Reception of a plurality of good messages advantageously provides a CAN protocol controller device which exits its busoff state with a high degree of confidence that the fault that caused the node to enter the busoff state has been cleared.

U.S. Patent No. 5,596,437

X-ray device
Inventors: Heins; Erich-Jurgen, Uetersen, Federal Republic of Germany
Assignees: U.S. Philips Corporation, New York, NY

Abstract

The invention relates to an X-ray device including a number of components to each of which is assigned a data transmission node working by the CAN protocol whose data input and data output are in mutual communication with other data transmission nodes via transmitters and receivers, the data transmission nodes being connected to the relevant associated components through connection lines. A fast and reliable data transmission is safeguarded in that the transmitter and receiver of at least some of the data transmission nodes are constructed for wireless transmission, and in that these transmitters or receivers are so controlled that they send data to at least the wireless receivers of other data transmission nodes and receive data from the wireless transmitters of at least the other data transmission nodes, as applicable.

First Claim

1. An X-ray device comprising a multiplicity of operative components which communicate automatically with each other and cooperate to form said X-ray device, a plurality of said operative components being controlled in response to control commands transmitted from other ones of said components and each of said operative components being assigned a data transmission node working by the Controller Area Network protocol, the data transmission nodes being in mutual communication with each other via a data transmission system for transmission of data between said components including transmission of said control commands to said plurality of controllable components, the data transmission nodes being connected to the relevant associated components through connection lines, wherein said data transmission system comprises a first wireless transmitter and a first wireless receiver serving a first group of one or more data transmission nodes, a second wireless transmitter and a second wireless receiver serving a second group of one or more data transmission nodes and a third wireless transmitter and a third wireless receiver serving a third group of one or more data transmission nodes, each of said wireless transmitters serving any particular group of nodes being positioned for simultaneous broadcast mode wireless communication with each of said wireless receivers serving any other group of nodes.

U.S. Patent No. 5,600,782

Can interface with enhanced fault confinement
Inventors: Thomson; Thomas W. S., Santa Cruz, CA
Assignees: National Semiconductor Corporation, Santa Clara, CA

Abstract

A CAN node having an enhanced fault recovery system is disclosed. The CAN node includes a CAN protocol controller device which reconnects to a CAN bus from the node's busoff state only after the node has successfully decoded 128 good messages from other devices on the CAN bus. Such a system advantageously provides a CAN node which exits its busoff state with a high degree of confidence that the fault that caused the node to enter the busoff state has been cleared. The protocol controller device uses the eleven recessive bits that start at the acknowledgement delimiter and finish at the end of the third bit of intermission to recognize that a single message has been successfully decoded.

U.S. Patent No. 5,617,282

Data communication system
Inventors: Rall; Bernhard, Ulm, Federal Republic of Germany; Dorner; Jurgen, Wendlingen, Federal Republic of Germany
Assignees: Daimler-Benz AG, Stuttgart, Federal Republic of Germany

Abstract

A data communication system, particularly for motor vehicles, includes a bus system with transmission lines which connect terminal devices to a common node. A protective circuit is connected between the transmission lines and a reference potential such as ground. If the ground connection of one of the terminal devices becomes detached, this protective circuit allows communication among the remaining terminal devices. The protective circuit is simultaneously secured against destruction in case of a short circuit.

First Claim

1. A data communication system, comprising:

• a bus system which includes a symmetrical transmission line having first and second conductors, and an ohmic load impedance connected between the first and second conductors, the load impedance having a center tap; and
• a protective circuit having a current-voltage characteristic, the protective circuit being connected between the center tap of the load impedance and a reference potential, the protective circuit including means for dividing the current-voltage characteristic into regions depending on the voltage across the protective circuit, the regions of the current-voltage characteristic including
• a first region in which no current flows through the protective circuit when the voltage across it is below a threshold voltage, the threshold voltage being higher than a normal voltage on the transmission line during data communication,
• a second region in which current through the protective circuit rises steeply with increasing voltage when the voltage across the protective circuit is between the threshold voltage and a knee voltage, and
• a third region in which current through the protective circuit is limited when the voltage across it is above the knee voltage.

U.S. Patent 6,151,298

Electronic bus system

Inventors: Bernhardsson, Sture; Björn, Fredrik; Nilsson, Göran

Assignee: NOB Elektronik AB

Abstract

An electronic bus system comprises a bus wire (BW) with at least two signal transmission wires (W1, W2) and a left and a right end, which are each defined by a terminating resistor connecting the signal transmission wires to each other. A plurality of electronic control units (ECU-ECUn) are between the two ends of the bus wire (BW) connected to the signal transmission wires (W1, W2) and are adapted, via these, to transmit and receive electric signals. The bus wire (BW) is divided into a plurality of sections (S1-Sn), which are interconnected by means of connecting circuits (CC1-CCn), and forms an annular unit. Each connecting circuit (CC1-CCn) comprises relay means, by means of which each connecting circuit, coordinated with the other connecting circuits, can connect at least one terminating resistor integrated therein, in order to define the left and/or right end of the bus wire (BW).