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Viii. dxp protocol, Overview, Hello handshake – SurgeX CM-1115-RT-AR User Manual

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CM-1115(20)-RT-AR User Manual

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VIII. DxP Protocol


Overview
The DxP Protocol is a packet-based protocol designed to be extensible. This protocol is
transmitted over TCP on a user-defined port. The factory default DxP port is 9100.

The protocol uses a Hello handshake to establish unique sequence numbers to allow for
advanced security when AES encryption is used. With AES enabled, all messages must
be encrypted with the AES Passphrase set in the device.

After the Hello, a Command and Response sequence follows. Any number of
Comma

nd → Response sequences are permitted after Hello.




Hello Handshake

The client sends a Hello message in the form of a text string ‘hello-000’. The DxP
enabled device will respond with a packet containing the unsigned 16 bit sequence
number. This sequence number is incremented by the client and server with each
correct packet sent.


Example:

Client

Server

hello-000

1234

(seq 1234)

Command

(seq 1235)

Response

Command

(seq 1237)

Response