CAN Bus Workshop_Version 03__06-2008_EN.pdf - 第76页
1 - 14 S tudent Gu ide CAN BUS Wor kshop 3 CAN BU S Editio n 06/200 8 14 23 D at um 06 /20 0 8 Ver s io n 0 3 C A N B u s W o rk sh op Ma t hia s M ic h el SIPL ACE Ca mp us Automati on and Driv es 3. Beis pi ele für m ö…
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Student Guide CAN BUS Workshop
Edition 06/2008 3 CAN BUS
13
21Datum06/2008 Version 03 CAN Bus Worksh op Mathias Michel
SIPLACE Campus
Automation and Drives
3. Messung der Spannungspegel
4. Check the dominant level
Dominant Level = Logic „0“
You need an oscilloscope to measure the dominant level.
To minimize the extent to which the measurement system influences the CAN signals, keep the
measurement line as short as possible.
- Connect the CAN Test Box to the service plug of the COM unit.
- Connect the oscilloscope to the BNC connectors CAN_H and CAN_L.
- Switch ON the machine
- To simulate CAN bus communication, you can start a version query in Sitest or Caccia.
- You can now check the signal voltage levels on the oscilloscope.
You should receive a value of 3.5V ( 2.75 - 4.5V) for CAN_H and of 1.5V (2.0 - 1.0V) for CAN_L
Voltage value:
CAN_H 3.5V ( 2.75 – 4.5V);
CAN_L 1.5V (2.0 – 1.0V)
3. Checking the CAN BUS voltage
level
22Datum06/2008 Version 03 CAN Bus Workshop Mathias Michel
SIPLACE Campus
Automation and Drives
3. Beispiele für mögliche Fehlerquellen
Short circuit between CAN High – Signal and GND
CAN High - Level
CAN Low - Level
3. Example for CAN BUS Errors
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Student Guide CAN BUS Workshop
3 CAN BUS Edition 06/2008
14
23Datum06/2008 Version 03 CAN Bus Workshop Mathias Michel
SIPLACE Campus
Automation and Drives
3. Beispiele für mögliche Fehlerquellen
Short circuit between CAN High – Signal and CAN Low - Signal
CAN High - Level
CAN Low - Level
3. Example for CAN BUS Errors
24Datum06/2008 Version 03 CAN Bus Workshop Mathias Michel
SIPLACE Campus
Automation and Drives
3. Beispiele für mögliche Fehlerquellen
Short circuit between CAN Low – Signal and GND
CAN High - Level
CAN Low - Level
3. Example for CAN BUS Errors
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Student Guide CAN BUS Workshop
Edition 06/2008 3 CAN BUS
15
25Datum06/2008 Version 03 CAN Bus Workshop Mathias Michel
SIPLACE Campus
Automation and Drives
Record of CAN telegrams during placement, with aid of the CAN Test Box
Error counter (Error Frames) = 0 Error counter (Error Frames) = 1
3. Beispiel Error Frames
3. Example of Error Frames
Settings oscilloscope
26Datum06/2008 Version 03 CAN Bus Workshop Mathias Michel
SIPLACE Campus
Automation and Drives
Error counter (Error Frames) = 3
3. Beispiel Error Frames
3. Example of Error Frames
Record of CAN telegrams during placement, with aid of the CAN Test Box