Chronos - A Multifunctional Response and Stimulus Device
Chronos is a powerful USB-based response and stimulus device manufactured by Psychology Software Tools. Chronos allows the accurate collection and verification of tactile, auditory, visual, and analog responses along with the precise source of audio and generic analog output timing. Chronos features millisecond accuracy and consistent sound output latencies across machines. Chronos includes 16 digital inputs and 16 digital outputs, eliminating the need for a parallel port. The Photo Sensor accessory (included) can be used on CRT, LCD, and projection displays to detect stimulus onset events, refreshes, and measure rise and fall times. All responses collected are synchronous to the E-Prime® time domain. Multiple Chronos devices can be connected to a single PC. The Chronos back panel features Kensington lock support to secure the device (lock not included).
Serial Response Box
The Serial Response Box (SRBox) manufactured by Psychology Software Tools is designed for optimal performance with E-Prime. The SRBox transmits the current state of its inputs to E-Prime every 1.25 milliseconds. When E-Prime observes an initial transition on any of the SRBox inputs, it generates a response with a timestamp that corresponds to this initial transition. E-Prime will then ignore any subsequent transitions on that input for a brief period of time known as the debounce period. The debounce period prevents E-Prime from registering switch bounce as additional responses from the participant. The initial transition is timestamped in order to minimize the variance caused by the inconsistent duration of switch bounce. When the debounce period for the input expires, E-Prime will resume observation of the input for further initial transitions.
Using Third-Party response devices
Response boxes can be made in-house or purchased from another vendor. When working with such devices, however, note that the Chronos / SRBox input commands in script are only to be used with a Psychology Software Tools-supplied response box. When working with a non-Psychology Software Tools response device, you will need to use either Port or Serial commands, depending on how the box is connected to your machine.
NOTE: If a third party vendor claims that their device is compatible with E-Prime, then contact that vendor for integration information.
See TIMING: E-Prime 3.0 Timing Data  for timing information with response devices and E-Prime 3.0.
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