Athena 16C series, Руководство пользователя

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15
Message Formats
All messages adhere to the general format of:
[START CHAR][ID][ZONE][TYPE][PARAM][ERROR]
[DATA][CHKSUM][END CHAR]
START CHAR
This is a single character which designates the start of the mes-
sage. For a Request message, this character is the ASCII ‘$’ and
for a Response message, this character is the ASCII ‘%’.
ID
This is a two-character ID identifying the receiving controller.
Controller IDs go from 1-255 inclusively and all slaves in the net-
work must have unique IDs. The ID number of ‘00’, when used in a
request, designates a broadcast message that is used to address
all controllers in the network. See the section Request Message for
an explanation of the broadcast message.
In order to represent 255 with just two ASCII characters, a number
system known as the Message Code Numbering System is used.
In this system, the most significant digit is represented with the
numbers 0-9 and the letters A-Z and the least significant digit is
represented with the numbers 0-9. The numbers 0-9 have the
Digital
Communications
Option