The Device Access Code (DAC) is a 68 or 72 bit long data field in the Bluetooth frame. The DAC command can be used to access Bluetooth devices during paging. The Access Code consists of the 4 bit long data field for the preamble and the 64 bit long data field for synchronization; which is followed by the 4 bit long optional data field for the trailer. The entire data field begins with the Least Significant Bit( LSB).
The Device Access Code (DAC) is used in Bluetooth networks for special signaling to access the devices and is generated from the Bluetooth Device Address (BD_ADDR).