SurgeX SX-20NE-RT-AR - Manual (Page 24)

SX-20NE-RT-AR User Manual
Page 23
VIII. DxP Protocol
(continued)
DxP Packet
The packet is broken up into 2 parts: the Header and the Payload.
Header
The header is used to carry general information, such as is shown in the C programming
structure below:
typedef struct {
eCmnd command;
char[21] uName;
char[21] password;
uChar desc;
uChar param;
uint16 seq;
} THeader
Variable
Description
command Enumerated type that tells the DxP server what class of command is being
sent. See the Commands subsection for a full list of command classes.
uName Reserved for future use. It will contain the user name of a user on the ipIO that
is being accessed.
password Reserved for future use. It will contain the password of the user above.
desc Command descriptor that describes the individual command within a command
class. By extension it lets the server know what the payload is. There is a
different set of descriptors for each command class; see the Descriptors
subsection for a full list of descriptors by command class.
param Reserved for future use. Optional parameter that may be passed to the server
in addition to the descriptor.
seq The packet’s sequence number. Used as part of the security scheme.
Payload
The payload is determined by a combination of the command class and the descriptor. The
payloads are described with the descriptor; see the Descriptors subsection for details.