fd_can_protocol_legacy)=

MD FDCAN communication

he easiest way to communicate with MD controllers is to use a CANdle device connected to a PC. Even hough we are aware some customers want to integrate the MD controllers in their product with inimal setup to reduce the costs and the system’s complexity. This manual will guide you through he process of communicating with MD actuators from your custom FDCAN-capable master controller.

Hardware requirements

he main requirement for the host system is to be equipped with an FDCAN peripheral (either a uilt-in one or an external one) and an FDCAN transceiver capable of speeds up to 8Mbps. Lower aximum speed transceivers can be used as well, however for the cost of limited update rates. epending on your custom setup you should be able to integrate a 120 ohm terminating resistor on oth ends of your CAN bus.

{note} MD controllers from version 2.0 can be upgraded to software controlled termination. Please contact us for more information

Communication Structure

he communication stack is based on a register access using two frames - register read and register rite. The list of available registers can be found at the end of this chapter. All fields are ittle-endian - least significant byte first, and all float fields are 4 bytes long encoded in EEE-754 standard.

Default response

he default response is sent by the drive in case a register write operation was successful.

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BYTE 0 BYTE 1-2 BYTE 3 BYTE 4-7 BYTE 8-11 BYTE 12-15 BYTE 16-19 BYTE 20-23 NAME FRAME ID QUICK STATUS MOTOR TEMPERATURE MAIN ENCODER POSITION MAIN ENCODER VELOCITY MOTOR TORQUE OUTPUT ENCODER POSITION OUTPUT ENCODER VELOCITY TYPE uint8_t uint16_t uint8_t [*C] float [rad] float [rad/s] float [Nm] float [rad] float [rad/s] VALUE 0x0A 0x0000 - 0xFFFF 0 - 255 - - - - - /table> p>

n case the operation initiated by a frame was unsuccessful the MDxx will not respond.

Write register frame

rite register frame is used to modify values of the user-modifiable registers. Only registers with rite access can be modified.

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FRAME NAME DRIVE ID LENGTH BYTE 0 [ID] BYTE 1 BYTE 2-3 BYTE 4-X BYTE X+1-X+2 BYTE X+4-X+Y WRITE_REGISTER 10-999 X (64 max) 0x40 0x00 reg ID value reg ID value /table> p>

arams:

regID (uint16_t_legacy) - first register ID (please see the end of this section) value (uint8_t/uint16_t/uint32_t/float/char[]) - first register value to be written regID (uint16_t_legacy) - second register ID (please see the end of this section) value (uint8_t/uint16_t/uint32_t/float/char[]) - second register value to be written … (up to 64 bytes total)

hen all registers write operations succeed the drive will respond with default response.

Read Register Frame

ead register command is used to retrieve certain register values. The actuator will respond with a rame consisting of the addresses and values of the registers issued in the master request. The aster request should have the following form:

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FRAME NAME DRIVE ID LENGTH BYTE 0 [ID] BYTE 1 BYTE 2-3 BYTE 4-X BYTE X+1-X+2 BYTE X+4-X+Y READ_REGISTER 10-999 X (64 max) 0x41 0x00 reg ID 0x00 reg ID 0x00 /table> p>

hen all read operations succeed the 0x00 fields will be filled with appropriate register data when ransmitted back to master by the MDxx controller.

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FRAME NAME DRIVE ID LENGTH BYTE 0 [ID] BYTE 1 BYTE 2-3 BYTE 4-X BYTE X+1-X+2 BYTE X+4-X+Y Response to register read 10-999 X (64 max) 0x41 0x00 reg ID reg value reg ID reg value /table> p>

{warning} rame payload length must not exceed 64 bytes. 

Available registers

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reg name address read/write size limits description canId 0x001 RW uint32_t [10-2000] FDCAN bus id number canBaudrate 0x002 RW uint32_t [1e6;2e6;5e6;8e6] FDCAN bus baudrate canWatchdog 0x003 RW uint16_t [0-2500] FDCAN bus watchdog period in ms canTermination 0x004 RW uint8_t [0-1] CAN termination (available upon request) motorName 0x010 RW char[24] - motor name motorPolePairs 0x011 RW uint32_t [2;225] motor pole pair count motorKt 0x012 RW float >0 motor torque constant motorKt_a 0x013 RW float >0 optional parameter for phase specific torque constant motorKt_b 0x014 RW float >0 optional parameter for phase specific torque constant motorKt_c 0x015 RW float >0 optional parameter for phase specific torque constant motorIMax 0x016 RW float [1 - peak controller current] maximum phase current motorGearRatio 0x017 RW float - actuator gear ratio (ex 2:1 should be 0.5) <1 - reducer >1 - multiplier motorTorqueBandwidth 0x018 RW uint16_t [50-2500] torque bandwidth in Hz motorFriction 0x019 RO float32 - UNUSED motorStiction 0x01A RO float32 - UNUSED motorResistance 0x01B RO float [5mOhm-20Ohm] motor resistance in d axis motorInductance 0x01C RO float [5nH-100mH] motor inductance in d axis motorKV 0x01D RW uint16_t - motor KV rating [RPM/V] motorCalibrationMode 0x01E RW uint8_t [0;1] FULL = 0, NOPPDET = 1 motorThermistorType 0x01F RW uint8_t - - outputEncoder 0x020 RW uint8_t [0;1;2;3] NONE = 0, ME_AS_CENTER = 1, ME_AS_OFFAXIS = 2, MB053SFA17BENT00 = 3, CM_OFFAXIS = 4, M24B_CENTER = 5, M24B_OFFAXIS = 6 outputEncoderDir 0x021 RW uint8_t 0 RESERVED outputEncoderDefaultBaud 0x022 RW uint32_t 115200 optional parameter for setting default output encoder baudrate outputEncoderVelocity 0x023 RO float - output encoder velocity in rad/s (calculated in a 5kHz loop) outputEncoderPosition 0x024 RO float - output encoder position in rad (read in 5kHz loop) outputEncoderMode 0x025 RW uint8_t [0;1;2;3;4] NONE = 0, STARTUP = 1, MOTION = 2, REPORT = 3, MAIN = 4 outputEncoderCalibrationMode 0x026 RW uint8_t [0;1] FULL = 0, DIRONLY = 1 motorPosPidKp 0x030 RW float - position PID proportional gain motorPosPidKi 0x031 RW float - position PID integral gain motorPosPidKd 0x032 RW float - position PID derivative gain motorPosPidWindup 0x034 RW float - position PID integral windup limit motorVelPidKp 0x040 RW float - velocity PID proportional gain motorVelPidKi 0x041 RW float - velocity PID integral gain motorVelPidKd 0x042 RW float - velocity PID derivative gain motorVelPidWindup 0x044 RW float - velocity PID integral windup limit motorImpPidKp 0x050 RW float - impedance PD proportional gain motorImpPidKd 0x051 RW float - impedance PD derivative gain mainEncoderVelocity 0x062 RO float - main encoder velocity in rad/s (calculated in a 40kHz loop) mainEncoderPosition 0x063 RO float - main encoder position in rad (read in 40kHz loop) motorTorque 0x064 RO float - motor output shaft torque in Nm (read in 40kHz loop) runSaveCmd 0x080 WO uint8_t other than 0 to run save non-volatile memory runTestMainEncoderCmd 0x081 WO uint8_t other than 0 to run runs main encoder test routine runTestOutputEncoderCmd 0x082 WO uint8_t other than 0 to run runs output encoder test routine runCalibrateCmd 0x083 WO uint8_t other than 0 to run runs main calibration routine runCalibrateOutputEncoderCmd 0x084 WO uint8_t other than 0 to run runs output encoder calibration routine runCalibratePiGains 0x085 WO uint8_t other than 0 to run runs current PI loop calibration routine runRestoreFactoryConfig 0x087 WO uint8_t other than 0 to run reverts config to factory state runReset 0x088 WO uint8_t other than 0 to run resets the controller runClearWarnings 0x089 WO uint8_t other than 0 to run clears all warnings runClearErrors 0x08A WO uint8_t other than 0 to run clears non-critical errors runBlink 0x08B WO uint8_t other than 0 to run blinks onboard LEDs runZero 0x08C WO uint8_t other than 0 to run sets new zero position runCanReinit 0x08D WO uint8_t other than 0 to run reinitializes can peripheral calOutputEncoderStdDev 0x100 RO float - output encoder test result (standard deviation) calOutputEncoderMinE 0x101 RO float - output encoder test result (min error) calOutputEncoderMaxE 0x102 RO float - output encoder test result (max error) calMainEncoderStdDev 0x103 RO float - main encoder test result (standard deviation) calMainEncoderMinE 0x104 RO float - main encoder test result (min error) calMainEncoderMaxE 0x105 RO float - main encoder test result (max error) positionLimitMax 0x110 RW float - maximum valid position positionLimitMin 0x111 RW float - minimum valid position maxTorque 0x112 RW float - maximum torque maxVelocity 0x113 RW float - maximum velocity maxAcceleration 0x114 RW float - maximum acceleration maxDeceleration 0x115 RW float - maximum deceleration profileVelocity 0x120 RW float - profile velocity profileAcceleration 0x121 RW float - profile acceleration profileDeceleration 0x122 RW float - profile deceleration quickStopDeceleration 0x123 RW float - quick stop deceleration in case of a non-critical error positionWindow 0x124 RW float - position window within position is considered to be reached velocityWindow 0x125 RW float - velocity window within velocity is considered to be reached motionModeCommand 0x140 WO uint8_t - commands a motion mode change: IDLE = 0x00, POSITION_PID = 0x01, VELOCITY_PID = 0x02, RAW_TORQUE = 0x03, IMPEDANCE = 0x04, POSITION_PROFILE = 0x07, VELOCITY_PROFILE = 0x08 motionModeStatus 0x141 RO uint8_t - shows the currently set motion mode state 0x142 RW uint16_t - returns the internal state machine state of the controller targetPosition 0x150 RW float - sets target position in rad targetVelocity 0x151 RW float - sets target velocity in rad/s targetTorque 0x152 RW float - sets target torque in Nm userGpioConfiguration 0x160 RW uint8_t - 0 - OFF, 1 - AUTO-BRAKE, 2 - GPIO INPUT userGpioState 0x161 RO uint16_t - GPIO input state reverseDirection 0x600 RW uint8_t - used to change the direction of the main encoder when using other encoders than the onboard one. Always recalibrate after changing this setting shuntResistance 0x700 RO float [0.001 - 0.01] Current sense resistor value. Setting this register to a value that is not coherent with the hardware may damage the controller. In this cases warranty is not respected. buildDate 0x800 RO uint32_t - software build date commitHash 0x801 RO char[8] - commit hash firmwareVersion 0x802 RO uint32_t - - hardwareVersion 0x803 RO uint8_t - - bridgeType 0x804 RO uint8_t - type of the mosfet driver quickStatus 0x805 RO uint16_t - quick status vector mosfetTemperature 0x806 RO float - power stage temperature motorTemperature 0x807 RO float - motor temperature (if thermistor is mounted) motorShutdownTemp 0x808 RW uint8_t - temperature at which the MD series motor controller will enter IDLE mode mainEncoderErrors 0x809 RO uint32_t - main encoder errors outputEncoderErrors 0x80A RO uint32_t - output encoder errors calibrationErrors 0x80B RO uint32_t - calibration errors bridgeErrors 0x80C RO uint32_t - bridge errors hardwareErrors 0x80D RO uint32_t - hardware errors communicationErrors 0x80E RO uint32_t - communication errors motionErrors 0x810 RO uint32_t - motion errors /table>