DPA protocol uses byte structured messages to communicate at IQMESH network. Every message always contains four mandatory parameters NADR, PNUM, PCMD and HWPID (foursome from now). The message can optionally hold data (array of bytes often referred to as PData throughout the document) to be transmitted or received. They are always described next to the foursome throughout this document. Although foursome parameters are typically described next to each other in this document, they do not have to be stored at consecutive memory addresses in the real scenario. The same rule does not apply to the message data.
Please note that a Response, Confirmation and Notification (with a small exception) DPA messages always contain the same NADR, PNUM, and PCMD as the original DPA Request message except the response message is flagged by the most significant bit of PCMD.
All values wider than byte are encoded using little-endian style unless otherwise specified.
Symbols, variables, structures, methods, etc. mentioned in this document are defined in header files DPA.h and DPAcustomHandler.h. Please consult IQRF OS documentation whenever an IQRF OS function is referenced in this document.