Control Area Network Communication (CAN)
CAN Velocity data read - refer to candump.c
candump picture
How to save CAN Log
candump -l slcan0
Abbreviation
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Process Data Object (PDO)
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Service Data Object (SDO)
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Communication Object (COB)
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Data Length Code (dlc)
Information on COB and mapped PDO.
RxPDO : Asynchronous TxPDO : Asynchronous and RTR only
| Object | COB-ID | PDO Mapping |
|---|---|---|
| RxPDO1 | 0x00000201 | Controlword (dlc = 2) |
| RxPDO2 | 0x00000301 | Controlword + Modes of Operation (dlc = 3) |
| RxPDO3 | 0x00000401 | Controlword + TargetVelocity (dlc = 6) |
| RxPDO4 | 0x00000501 | Controlword + TargetPosition (dlc = 6) |
| TxPDO1 | 0x00000181 | Statusword (dlc = 2) |
| TxPDO2 | 0x00000281 | ActualPosition (dlc = 4) |
| TxPDO3 | 0x00000381 | ActualVelocity (dlc = 6) |
| TxPDO4 | 0x00000481 | None |
| Process Data Object | Data type | dlc |
|---|---|---|
| Controlword | Unsigned16 | 4 times 4 bits = 2 times 8 bits (dlc = 2) |
| Modes of Operation | Unsigned8 | 2 times 4 bits = 1 times 8 bits (dlc = 1) |
| TargetVelocity | Integer32 | 8 times 4 bits = 4 times 8 bits (dlc = 4) |
| TargetPosition | Integer32 | 8 times 4 bits = 4 times 8 bits (dlc = 4) |
| statusword | Unsigned16 | 4 times 4 bits = 2 times 8 bits (dlc = 2) |
| Modes of Operation Display | Unsigned8 | 2 times 4 bits = 1 times 8 bits (dlc = 1) |
| ActualVelocity | Integer32 | 8 times 4 bits = 4 times 8 bits (dlc = 4) |
| ActualPosition | Integer32 | 8 times 4 bits = 4 times 8 bits (dlc = 4) |
cpp Code Operation Mode: Profile Velocity Mode
Modes Of Operation Info : 3 (Profile Velocity Mode), 1 (Profile Position Mode), ... etc
How to compile and execute the code.
CAN_TEST $ rm -rf build
CAN_TEST $ mkdir build
CAN_TEST/build $ cmake ..
CAN_TEST/build $ make
How to check serial port name
dmesg | grep tty
Construct CAN frame (Frame name = slcan0)
$ sudo slcand -o -c -f -s6 /dev/ttyUSB0 && sudo ifconfig slcan0 up
| -s parameter | Kbit/s |
|---|---|
| -s0 | 10 Kbit/s |
| -s1 | 20 Kbit/s |
| -s2 | 50 Kbit/s |
| -s3 | 100 Kbit/s |
| -s4 | 125 Kbit/s |
| -s5 | 250 Kbit/s |
| -s6 | 500 Kbit/s |
| -s7 | 800 Kbit/s |
| -s8 | 1000 Kbit/s |
Execute the code
CAN_TEST/build $ ./CAN_TEST
byte_test.cpp
The purpose of the code file is to transmit data to the EPOS2 drive.
The below picture shows how the input data is inserted into the motor drive.
CAN Interface setup
sudo modprobe can && sudo modprobe can_raw && sudo modprobe mttcan
CAN setup
can0 interface is set.
Bit rate set 1000 kbps
sudo ip link set can0 type can bitrate 1000000
CAN network up
sudo ip link set up can0
Check
ifconfig can0
Complie the code
mkdir build
cmake ..
make
Execute the code
./read_write_test
Interrupt : press ctrl + c