Presentation on theme: "CAN bus signal monitoring using the DL850V Yokogawa Meters & Instruments Corporation."— Presentation transcript:
CAN bus signal monitoring using the DL850V Yokogawa Meters & Instruments Corporation
FORESIGHT INNOVATION QUALITY Page 2 Leading-edge Technologies What is CAN? Controller Area Network Developed by BOSCH in It is a de facto standard protocol, being used for communication between ECUs in a vehicle. It is used for data communication such as speed, RPM, break status, diagnosis information. It is widely being used for not only for vehicle but also power, vessel, railroad, medical equipment, FA, elevator, etc. Serial communication Master Slave
FORESIGHT INNOVATION QUALITY Page 3 Leading-edge Technologies Merit of using CAN Cutting Harness………low-cost, simple-design Cutting weight………..more economical Differential signal……noise reduction (safety) Error detection……….higher reliability Wire Harness Using CAN Simple Light weight complicated
FORESIGHT INNOVATION QUALITY Page 4 Leading-edge Technologies (Reference) Example of in-vehicle network The source: Renesas Electronics Corporation (Japan) For Multi-Media For Fault-diagnosis (controlled legally) Fault-diagnosis CAN diagnosis tool Sub-Network For Power Train Chassis MD/CD changer Lamp Instrument panel Keyless Door Switch Sensor Squibb Air-bag Control For Safety For Body Control Sub-Network Gateway Sub-Network Tire Pressure EngineSteering
FORESIGHT INNOVATION QUALITY Page 5 Leading-edge Technologies (Reference) CAN regulation OSI basic reference model Both datalink layer and Physical layer are defined. In addition to ISO-defined standards, there are some other CAN-regulated standards such as SAE J2284, J2411. Application Layer Presentation Layer Session Layer Transport Layer Network Layer LLC Physical Layer Data Link Layer (ISO11898, ISO ) MAC Acceptance, Filtering (1:1, 1:n communication) Overload (not ready yet) Notice Resend when an error is occurred Frame Generation (Data, Remote, Error, Overload frame) Bus monitoring, Error detection and notice Acknowledgement Arbitration Data Link Layer Physical Layer (ISO11898, ISO ) Bit, Timing, Synchronization, Resynchronization, Communication speed Bus characteristic, Driver, etc. Controlled by Software Controlled by Hardware Processed by CAN controller Processed by CAN Transceiver
FORESIGHT INNOVATION QUALITY Page 6 Leading-edge Technologies CAN bus and Node(s) ECU CAN bus = Two wire Max. 30 nodes
FORESIGHT INNOVATION QUALITY Page 7 Leading-edge Technologies Signal flow in the CAN….1 Packet signal, called FRAME, carried and received. ECU CAN bus FRAME
FORESIGHT INNOVATION QUALITY Page 8 Leading-edge Technologies Each node can send a frame freely, also can receive a frame freely. Signal flow in the CAN….2 ECU CAN bus FRAME Multi-master
FORESIGHT INNOVATION QUALITY Page 9 Leading-edge Technologies Features of CAN Differential Signal Multi-master Any node can send out a message when the bus is open. The order of priority for sending Identifier field in a message determines the order of priority. System flexibility Each node has no specific address, so easy for adding and removing. Flexibility for communication speed It can be set according as a scale of network, function of system. Advanced error handling Excellent in error detection, notice and recovery Data request Any node can generate data output request for the other node.
FORESIGHT INNOVATION QUALITY Page 10 Leading-edge Technologies ECU (Node) connection Differential signal Node N (max.30) Node 1 CAN_H CAN_L CAN Bus Line Terminator 120 ohm Node 2 Terminator 120 ohm CPU CAN Controller TX0 TX1 RX0 RX1 Transceiver Communicate via differential signal (CAN_H/CAN_L) Max. 30 nodes can be connected. Terminators must be placed at the end of bus line. It is classified into two type of standards, Hi-speed CAN and Low-speed CAN. The boundary is 125kbps. The figure below shows an example of Hi-speed CAN. (Terminated by 120 ohm) Each node is connected to CAN bus via the CAN Controller and CAN Transceiver.
FORESIGHT INNOVATION QUALITY Page 11 Leading-edge Technologies CAN Topology The Bus type is typically being used. 1. Bus type 2. Star type 3. Ring type
FORESIGHT INNOVATION QUALITY Page 12 Leading-edge Technologies A variety of frames Data Frame A DATA FRAME carries data from a transmitter to the receivers. Remote Frame A REMOTE FRAME is transmitted by a bus unit to request the transmission of the DATA FRAME with the same IDENTIFIER. Error Frame An ERROR FRAME is transmitted by any unit on detecting a bus error. Overload Frame An OVERLOAD FRAME is used to provide for an extra delay between the preceding and the succeeding DATA or REMOTE FRAMEs. The DL850V can monitor only a data frame. Start of Frame Arbitration Field Control Field Data Field CRC Field ACK Field End of Frame Start of Frame Arbitration Field Control Field CRC Field ACK Field End of Frame
FORESIGHT INNOVATION QUALITY Page 13 Leading-edge Technologies Data Frame format (Packet structure) ACK CRC Data Control Field Arbitration Field Recessive Dominant SOF 4 ID Bit RTR r 0-64 (0-8 byte)15111 EOF 73 Start of Frame: Marks the beginning of DATA FRAMES and REMOTE FRAMEs. Identifier Field: Indicates the contents of message, also can be used for the order of priority for bus access. Standard format:11bit Extended format:29bit (DL850V supports both.) RTR: Remote Transmission Request BIT. In DATA FRAMEs the RTR BIT has to be dominant. Within a REMOTE FRAME the RTR BIT has to be recessive. Control Field: It includes the DATA LENGTH CODE and two bits reserved for future expansion. Data Field: The DATA FIELD consists of the data to be transferred within a DATA FRAME. (Max. 8-byte(64- bit)) CRC Sequence & CRC Delimiter : It is the frame check sequence. The CRC SEQUENCE is followed by the CRC DELIMITER which consists of a single recessive bit. Ack Slot & Ack Delemiter : All nodes having received the matching CRC SEQUENCE report this within the ACK SLOT by superscribing the recessive bit of the TRANSMITTER by a dominant bit. End Of Frame: A flag sequence consisting of seven recessive bits. DLC r
FORESIGHT INNOVATION QUALITY Page 14 Leading-edge Technologies CAN data frame and physical data 142h b h2468h0302h RPM Integrating revolution counter Oil pressure Identifier Field Data Field Air cond. ON/OFF 1 High beam indicator 0 With CAN data frames, multiple data (physical data) are carried and received under a single ID. Ex.)
FORESIGHT INNOVATION QUALITY Page 15 Leading-edge Technologies Tool lineup for CAN bus ECU CAN bus FRAME CANalyzer (Vector) DLM2000 SB5000 WE7000 DL850V
FORESIGHT INNOVATION QUALITY Page 16 Leading-edge Technologies Measurement targets of the CAN tools Target Model Mainly for CAN hardware design Mainly for CAN software design
FORESIGHT INNOVATION QUALITY Page 17 Leading-edge Technologies The difference of observed waveform DLM2000, SB5000 waveform = Trend of voltage signal of the CAN bus DL850V waveform = Trend of physical value(signal) that is transmitted on the CAN bus
FORESIGHT INNOVATION QUALITY Page 18 Leading-edge Technologies Simultaneous observation of CAN data and the analog signal(s) Analog signals Engine Transmission Brake Strain gauge Acceleration Sensor Pressure sensor ECU Analog Signals CAN bus thermocouple DL850V CAN data
FORESIGHT INNOVATION QUALITY Page 19 Leading-edge Technologies CAN bus data monitoring E/G RPM Vehicle speed Data Trend of RPM Trend of speed CAN Frame You can check physical value trends of CAN bus data and the corresponding actually measured waveforms on the same screen at once. Multi kinds of data transmitted on the CAN bus can be monitored at the same time via a single wire. ECU1 ECU2 ECU3 CAN monitoring of CAN protocol communication data(signal) as an analog trend wafeform(s). What is CAN monitor function? Comparison and verification of actually measured signals and CAN bus signals Trend display Each signal(s) can be extracted from a single CAN bus line.
FORESIGHT INNOVATION QUALITY Page 20 Leading-edge Technologies Sampled Data and Displayed Waveforms Extracted data is stored in memory at up to 100 ks/s while simultaneously being displayed on screen as trends. Sampled data (trend waveform data) can be saved into files.
FORESIGHT INNOVATION QUALITY Page 21 Leading-edge Technologies Pressure sensor (analog) CAN signal (Physical layer) Current (CAN monitor waveform 1 ) CAN bus 1 frame Two signals transmitted by a single frame are trend- displayed as two waveforms. Observed waveform example You can use Vector Informatik's CANdb database file (.dbc format) to indicate the field being monitored (acquired). Pressure (CAN monitor waveform 2) The timing of analog signal and CAN communication signal can be checked.
FORESIGHT INNOVATION QUALITY Page 22 Leading-edge Technologies Sub channel definition Sub channel(s) means the signal definitions of target item(s) 142h b h2468h0302h CH3 CH1 CH2 Number of sub CH IDStart bitBit length (Note) Integrating revolution counter Oil pressure RPM Up to 16CH(Signal)/por t can be defined. (sub-CH) Note: Up to 16 of bit length can be defined by module.
FORESIGHT INNOVATION QUALITY Page 23 Leading-edge Technologies Sub channel definition display (Preliminary) Factor, Offset, Unit: Scaling factor and unit for converting physical value. Signal definition setting (see the previous page) Import of setup configuration file Port Setup (refer to the next page) Byte Count:Target byte length Start Bit:Position of the start bit (counted from LSB) Bit Count:Target bit length Byte Order: (Big): transmitted in from upper byte to lower byte order (Little): transmitted in from lower byte to upper byte order Note: The bit data in a byte is transmitted by MSB first.
FORESIGHT INNOVATION QUALITY Page 24 Leading-edge Technologies Port Setup Preliminary Terminator: When it turn to ON, the module- built-in terminator is inserted between CAN_H and CAN_L. Bit Rate: Communication speed of the bus Sample Point: Position for detecting dominant or recessive in a single bit. Sync Jump Width: It can be used for correction of clock cycle in a single bit for re-synchronization. Bit Sample Num: It can be used for designating the number of sample point(s). Setup configuration for input port Listen Only: When it turns to ON, any signal(Frame, Ack) is not outputted from the DL850V.
FORESIGHT INNOVATION QUALITY Page 25 Leading-edge Technologies *1 The CANdb file(.dbc) is a signal definition database defined by CANdb or CANdb++ presented by Vector Informatik. Using Symbol Editor free software, a message and signal can be selected(imported) from CANdb, then export as the signal labels to the DL850V. Drug & Drop Edits Usage of CAN db database Signal labels can be imported from CANdb database *1 CAN db file imports **.dbc Definition file for exporting to the DL850V. **.sbl
FORESIGHT INNOVATION QUALITY Page 26 Leading-edge Technologies Outputting Frame Data (Preliminary) Single specified (defined) data frames or remote frames can be output (manually, at desired timing). Setting the condition of frame output A designated frame is output when Execute is set.
FORESIGHT INNOVATION QUALITY Page 27 Leading-edge Technologies Model CAN Bus Monitor module main specifications Input ports: 2 (16 signals x 2 ports) Number of Channels : 16 signals/1port Connector type: D-sub 9 pin (male), Isolated (across port and main unit, across each port) Supported protocols: Physical layer: ISO (High Speed Communication) CAN in Automation: CAN2.0B (Standard & extended message format ) Bit rates: 10 k, 20 k, 33.3 k, 50 k, 62.5 k, 66.7 k, 83.3 k, 125 k, 250 k, 500 k, 800 k, 1 Mbps Max. sampling rate: 100kS/s(when using 1signal/1port) Max. 2 modules can be installed for the specified slot(s) in a single DL850V main frame. There are some competitive memory recorders which has CAN monitoring capability. However, the DL850V has a certain advantages over them such as higher sampling rate, easy for handling and costs.