TRACKPixx Device

Available on macOS

Description

Interface to a TRACKPixx3 device.

This component also exposes the functions of the DATAPixx3 device to which the TRACKPixx is connected. To use both the TRACKPixx and DATAPixx in an experiment, create a single TRACKPixx Device. To use the DATAPixx without the TRACKPixx, create a DATAPixx Device instead.

Signature

iodevice/trackpixx

Required Parameters

distance

Example:

100

Distance from subject’s eyes to camera lens (in centimeters)

lens_type

Options:
25mm
50mm
75mm

Camera lens type

iris_expected_size

Example:

100

Expected size of the subject’s iris in the camera image (in pixels)

update_interval

Example:

3ms

MWorks will poll the device for new input data every update_interval microseconds

Optional Parameters

show_overlay

Default:

NO

If YES, the console monitor (i.e. the display connected to DATAPixx3 DisplayPort OUT2) will show the camera image and pupil center tracking positions in an overlay window

tracker_window_brightness

Default:

200

Brightness of the overlay window enabled by show_overlay. Must be an integer between 0 and 255 (inclusive).

ir_illuminator_intensity

Default:

8

Intensity of the infrared illuminator. Must be an integer between 0 and 8 (inclusive).

fixation_speed

Default:

20

Eye velocity threshold below which to classify fixations (in eye position units per second)

fixation_samples

Default:

25

Minimum number of consecutive samples required to classify a fixation event

saccade_speed

Default:

60

Eye velocity threshold above which to classify saccades (in eye position units per second)

saccade_samples

Default:

10

Minimum number of consecutive samples required to classify a saccade event

species

Options:
human
nhp
Default:

human

Subject species

tracking_mode

Options:
standard
headfixed_nhp
Default:

standard

Tracking mode

tracker_time_seconds

Variable in which to store time of sample (in seconds) on TRACKPixx clock

screen_lx

Variable in which to store Cartesian screen coordinate for x component of left eye

screen_ly

Variable in which to store Cartesian screen coordinate for y component of left eye

pupil_size_l

Variable in which to store diameter of left eye pupil

screen_rx

Variable in which to store Cartesian screen coordinate for x component of right eye

screen_ry

Variable in which to store Cartesian screen coordinate for y component of right eye

pupil_size_r

Variable in which to store diameter of right eye pupil

fixation_l

Variable in which to store left eye fixation state (true when fixating, false otherwise)

fixation_r

Variable in which to store right eye fixation state (true when fixating, false otherwise)

saccade_l

Variable in which to store left eye saccade state (true when in saccade, false otherwise)

saccade_r

Variable in which to store right eye saccade state (true when in saccade, false otherwise)

raw_lx

Variable in which to store pupil-to-corneal reflection vector x component for left eye

raw_ly

Variable in which to store pupil-to-corneal reflection vector y component for left eye

raw_rx

Variable in which to store pupil-to-corneal reflection vector x component for right eye

raw_ry

Variable in which to store pupil-to-corneal reflection vector y component for right eye

clock_offset_nanos

Variable in which to store the computed offset (in nanoseconds) between the device clock and MWorks’ clock.

The clock offset is recomputed once per second and is used to convert DATAPixx event and sample times to MWorks times. Use this parameter if you want a record of the computed clock offsets in your event file.

enable_dout_pixel_mode

Default:

NO

If YES, the digital output port will be used to output the RGB value of the first upper left pixel of the screen.

In this mode, the digital output port cannot be used for bit output or word output channels. However, these channels may still be configured on the digital input port.

enable_dout_vsync_mode

Default:

NO

If YES, the VSYNC signal will be output on bit 23 of the digital output port.

This mode cannot be enabled if enable_dout_pixel_mode is set to YES.

enable_din_stabilize

Default:

NO

If YES, digital input transitions are recognized only after the entire digital input bus has been stable for 80 nanoseconds

enable_din_debounce

Default:

NO

If YES, after a digital input transitions, further transitions will be ignored for the next 30 milliseconds

enable_dout_din_loopback

Default:

NO

If YES, digital output bits are looped back to the corresponding digital input bits. This is useful primarily for testing the device.

din_event_buffer_size

Default:

100

Transitions on digital input bits 0-15 are logged to an on-device buffer and read by MWorks at the rate specified by update_interval. This parameter sets the maximum size (in number of events) of the buffer. If the buffer is too small, writes will “wrap”, and new events will overwrite old ones.

analog_input_data_interval

Example:

1ms

Interval between acquired samples on analog input channels (microseconds)

enable_dac_adc_loopback

Default:

NO

If YES, analog outputs are looped back to analog inputs as follows:

DAC_DATA0 → ADC_DATA0/2/4/6/8/10/12/14
DAC_DATA1 → ADC_DATA1/3/5/7/9/11/13/15
DAC_DATA2 → ADC_REF0
DAC_DATA3 → ADC_REF1

This is useful primarily for testing the device.

autostart

Default:

NO

If YES, the device will start I/O automatically (as if by an implicit Start IO Device action) when the experiment starts running.

Note: Device I/O will always stop automatically when the experiment stops running, irrespective of this setting.

alt

Alternative device to use if this one fails to initialize (e.g. because the required hardware is not available). If #allowAltFailover is set to 0 or false, this parameter is ignored.

Placement

Allowed at top level:

Yes

Allowed parent:

Folder

Allowed children:

DATAPixx Analog Input Channel, DATAPixx Analog Output Channel, DATAPixx Bit Input Channel, DATAPixx Bit Output Channel, DATAPixx Word Input Channel, DATAPixx Word Output Channel