A cedrusPad object is optional. You only need to make one if you want to change a property from default.
An object of type cedrusPad provides options for a Cedrus response pad, e.g. for use by a cedrusPress element. You can have multiple cedrusPad objects in an experiment. In an experiment script you can make one outside trials with the command cedrusPadObject and add it with addToExperiment.
A string that is name of the serial port the pad is on, as accepted by Psychtoolbox IOPort('OpenSerialPort'). From Psychtoolbox documentation: On Windows this could be, e.g. <cds>"COM1"<cds>, <cds>"COM2"<cds>, etc.; on Mac it is a path to a BSD device file, e.g. <cds>"/dev/cu.usbserial-FT3Z95V5"<cds> for a serial-over-USB device with unique ID FT3Z95V5; on Linux e.g. <cds>"/dev/ttyS0"<cds> for the first real serial port, <cds>"/dev/ttyUSB0"<cds> for the first serial-over-USB device, etc.
Default: full baud
By default the pad connection runs at 115.2k baud. If you set fullBaud = <cd>false<cd>, it reduces to 57.6k. Maybe helpful if pad connection/operation is unreliable on your system at the full rate.