Controlling video devices

摘要

Disclosed is an apparatus for controlling video devices by transmitting RS-422 command strings to the devices comprising, a controller for preparing each RS-422 command string in advance of an execution time at which the command is to be executed; a buffer for storing each RS-422 command string and a respective associated time of execution; and a buffer scanner operable to compare a current time with the execution times of each buffered command and to transmit to the respective video device any commands stored in the buffer for which the associated execution time is the same as or before the current time.