This Standard ECMA-40 defines the frame structure for bit sequence independent data transmission. This structure is intended for use in High-Level Data Link Control (HDLC) applications.
This Standard defines in detail the relative positions of the various components of the basic frame, the bit combination of the frame delimiting sequence, the mechanism used to obtain total transparency within the frame and the frame checking sequence used.
Other standards define the details of the address and control fields and the procedures used during the transmission.