09-09-2020, 02:42 PM
The analog card converts the digital eye tracking signal to an analog voltage that can be recorded by an external acquisition device. The analog output is typically used when some other analog physiological data is being collected concurrently with eye movements, such as MEG, EEG, EMG, etc. The analog eye tracking data can be sent to the same acquisition device in the same format as the other physiological recordings for ease of synchronization and analysis.
Only the X and Y gaze position and pupil size are available for each eye (6 separate channels), along with a strobe signal that is locked to the eye tracker sampling rate. The parsed gaze data (fixation, saccades, blinks, etc...) are not available in analog output format (this data is still available in EDF however). The analog signal can be susceptible to EM interference from other devices if the cabling is not properly shielded, so the care needs to be taken in the connection from the Host PC to the analog acquisition device.
If planning to use the analog card, please see Section 7 Appendix A: Using the EyeLink 1000 Plus Analog and Digital Output Card of the EyeLink 1000 User Manual or EyeLink 1000 Plus User Manual.
The channels used for data output will vary based on the settings used in ANALOG.INI and which eye(s) is / are tracked. The table below shows a full matrix of the possible data output assignments based on the tracking mode and the ANALOG.INI settings.
The analog card can also be used to send digital input and output triggers (TTL). See section 7.4 Digital Inputs and Outputs for more information on setting up the analog card for sending and receiving TTL triggers. Figure 7-1 includes the pin mappings for the Digital I / O channels.
Only the X and Y gaze position and pupil size are available for each eye (6 separate channels), along with a strobe signal that is locked to the eye tracker sampling rate. The parsed gaze data (fixation, saccades, blinks, etc...) are not available in analog output format (this data is still available in EDF however). The analog signal can be susceptible to EM interference from other devices if the cabling is not properly shielded, so the care needs to be taken in the connection from the Host PC to the analog acquisition device.
If planning to use the analog card, please see Section 7 Appendix A: Using the EyeLink 1000 Plus Analog and Digital Output Card of the EyeLink 1000 User Manual or EyeLink 1000 Plus User Manual.
The channels used for data output will vary based on the settings used in ANALOG.INI and which eye(s) is / are tracked. The table below shows a full matrix of the possible data output assignments based on the tracking mode and the ANALOG.INI settings.
The analog card can also be used to send digital input and output triggers (TTL). See section 7.4 Digital Inputs and Outputs for more information on setting up the analog card for sending and receiving TTL triggers. Figure 7-1 includes the pin mappings for the Digital I / O channels.