A device—also called a “device driver”—is a file that contains all the information our system needs in order to control a device, e.g. a projector, a display, TV, switcher or amplifiers by RS-232, IR or LAN.
Once the device is created, you don't need to worry about timing, how to turn on the device and what codes to send to change the source.
When you create a new device, it’s important you enter everything you need, verify that the timings are correct, and enter the appropriate data in the RS-232, IR and LAN sections so that you can control your device using any of these methods.
If the timing is incorrect and lets say you send the ON command to the device, and warm up time is set to a too low value, then the SOURCE command that follows, will be fired to soon and the device will not be ready to receive the command.
See the device driver as the gear that make the physical connection between the control system and the device you wish to control.