Initially, an input device is in REQUEST mode. The mode of the input device may be changed by calling the appropriate SET <input class> MODE function. After a call to the SET <input class> MODE function with the REQUEST parameter, there is no longer an evaluation process for the specified device and the device indicator is deleted from the list of receivers of its trigger. After a call with the SAMPLE parameter, a new evaluation process is created for the specified device, but the device identifier is deleted from the list of receivers of its trigger.