Oscilloscope

dev_motor_controller features on board oscilloscope functionality that is useful for inspecting the internal state at rates up to the main controller frequency. An example use of the oscilloscope is inspecting a step response of a current controller.

Oscilloscope features are:

Configurable sample rate.
Four source configurable channels, each with a depth of 1792 float32 values.
Rising and falling edge triggers with configurable source.

Oscilloscope Commands

Command	Type	Required	Description
`oscilloscope_sample_rate_hz`	uint32	Required	Set the sampling frequency of the oscilloscope. The oscilloscope frequency must be an even divisor of the current controller frequency.
`oscilloscope_trigger_source`	enum	Required	Sets the trigger source signal. See Oscilloscope Sources for a list of trigger sources.
`oscilloscope_trigger_config`	enum	Optional	Sets the trigger configuration. See Oscilloscope Trigger Configuration for a list of trigger configurations.
`oscilloscope_trigger_level`	float32	Required	Sets the level for the trigger. Once the trigger source passes this value the oscilloscope will sample until the channel arrays are full.
`oscilloscope_trigger_buffer_position`	uint32	Optional	Sets the position in the buffer where sampling commences. Valid values are between 0 and 1792. A parameter error will be returned for values larger than 1792. See Trigger Buffer Position for more details.
`oscilloscope_channel_0_source`	enum	Optional	Sets the channel 0 source signal. See Oscilloscope Sources for a list of sources.
`oscilloscope_channel_0`	float32	Optional	Contains the channel 0 sampled data. Total length is 1792 float32 values. All values must be read out.
`oscilloscope_channel_1_source`	enum	Optional	Sets the channel 1 source signal. See Oscilloscope Sources for a list of sources.
`oscilloscope_channel_1`	float32	Optional	Contains the channel 1 sampled data. Total length is 1792 float32 values. All values must be read out.
`oscilloscope_channel_2_source`	enum	Optional	Sets the channel 2 source signal. See Oscilloscope Sources for a list of sources.
`oscilloscope_channel_2`	float32	Optional	Contains the channel 2 sampled data. Total length is 1792 float32 values. All values must be read out.
`oscilloscope_channel_3_source`	enum	Optional	Sets the channel 3 source signal. See Oscilloscope Sources for a list of sources.
`oscilloscope_channel_3`	float32	Optional	Contains the channel 3 sampled data. Total length is 1792 float32 values. All values must be read out.
`oscilloscope_force_start`	command	Optional	The oscilloscope will immediately start sampling at the completion of this command, regardless of trigger configuration.
`oscilloscope_stop`	command	Optional	The oscilloscope will immediately stop sampling or waiting for the trigger and return to the stopped condition.
`oscilloscope_wait_trigger`	command	Optional	The oscilloscope will start sampling once the trigger conditions are met.
`oscilloscope_is_done`	bool	Optional	Returns true if the oscilloscope is finished sampling or off and false if the oscilloscope is waiting for the trigger or sampling.

Oscilloscope Trigger Configuration

Trigger configuration	Description
`osc_trigger_rising`	The oscilloscope will start sampling once the trigger source signal goes above the trigger level.
`osc_trigger_falling`	The oscilloscope will start sampling once the trigger source signal goes below the trigger level.

Oscilloscope Sources

Oscilloscope Source	Description
`mc_osc_sense_i_a`	Measured phase current (A). Phase A.
`mc_osc_sense_i_b`	Measured phase current (A). Phase B.
`mc_osc_sense_i_c`	Measured phase current (A). Phase C.
`mc_osc_foc_i_al`	Measured motor current (A). Al axis in AlBe frame.
`mc_osc_foc_i_be`	Measured motor current (A). Be axis in AlBe frame.
`mc_osc_foc_i_d`	Measured motor current (A). D axis in DQ frame.
`mc_osc_foc_i_q`	Measured motor current (A). Q axis in DQ frame.
`mc_osc_foc_i_d_cmd`	Current command (A). D axis in DQ frame.
`mc_osc_foc_i_q_cmd`	Current command (A). Q axis in DQ frame.
`mc_osc_foc_i_d_cmd_ff`	Current command (A) with any feedforward terms present. D axis in DQ frame.
`mc_osc_foc_i_q_cmd_ff`	Current command (A) with any feedforward terms present. Q axis in DQ frame.
`mc_osc_foc_v_d_cmd`	Voltage command (V) as output from current controller. D axis in DQ frame.
`mc_osc_foc_v_q_cmd`	Voltage command (V) as output from current controller. Q axis in DQ frame.
`mc_osc_foc_v_d_mod_cmd`	Modulated voltage command (normalised to DC bus voltage). D axis in DQ frame.
`mc_osc_foc_v_q_mod_cmd`	Modulated voltage command (normalised to DC bus voltage). Q axis in DQ frame.
`mc_osc_foc_v_al_mod_cmd`	Modulated voltage command (normalised to DC bus voltage). Al axis in AlBe frame.
`mc_osc_foc_v_be_mod_cmd`	Modulated voltage command (normalised to DC bus voltage). Be axis in AlBe frame.
`mc_osc_foc_duty_a_cmd`	Duty cycles as output to PWM unit. Phase A.
`mc_osc_foc_duty_b_cmd`	Duty cycles as output to PWM unit. Phase B.
`mc_osc_foc_duty_c_cmd`	Duty cycles as output to PWM unit. Phase C.
`mc_osc_sense_v_a`	Measured phase voltage (V). Phase A.
`mc_osc_sense_v_b`	Measured phase voltage (V). Phase B.
`mc_osc_sense_v_c`	Measured phase voltage (V). Phase C.
`mc_osc_foc_v_al`	Measured motor voltage (V). Al axis in AlBe frame.
`mc_osc_foc_v_be`	Measured motor voltage (V). Be axis in AlBe frame.
`mc_osc_foc_v_d`	Measured motor voltage (V). D axis in DQ frame.
`mc_osc_foc_v_q`	Measured motor voltage (V). Q axis in DQ frame.
`mc_osc_rotor_th_m`	Rotor mechanical position (Rad).
`mc_osc_rotor_th_e`	Rotor electrical position (Rad).
`mc_osc_rotor_th_internal_m`	Rotor mechanical position (Rad). Direct from encoder, no compensation applied.
`mc_osc_rotor_w_m`	Rotor mechanical speed (Rad/S).
`mc_osc_sense_vdc`	Measured DC bus voltage (V).
`mc_osc_i_mot`	Computed motor current (A).
`mc_osc_i_bus`	Computed bus current (A).

Trigger Buffer Position

The oscilloscope_trigger_buffer_position parameter allows placing the trigger point at any point within the sampling buffer. This feature is useful for examining signals that may occur around the trigger event, rather than immediately after the trigger event.

As an example, if oscilloscope_trigger_buffer_position is set to 896 (half the sample buffer length) then the trigger event will appear at the midpoint of the sample buffer, and the user will see half the signal before the trigger event and half after.