Ametek CEM/Humox, Руководство пользователя

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A-2 | Thermox CEM/Humox Analyzer
Command Message Format
The command message format is as follows:
Where:
The
Start Character
is the greater than character (“>”, which is ASCII decimal
character 62 or hexadecimal character 3E).
The
Node Address
is from 00-FF, and is represented as two hex ASCII characters.
Each controller has a unique node address (see the “Communication/Node Ad-
dress” section in the Setup Key chapter for help on specifying node addresses for
controllers). Note, however, that the maximum number of controllers that can be
connected on the network is 32.
The
Command Letter
is from ASCII A-Z (upper case only).
Data is a string of characters whose meaning depends on the command (see below)
and where the number of characters returned also depends on the command. Limit
is 20 characters.
The
Checksum
is the sum of all the preceding characters (excluding the >> char-
acter) - modulo 256.
The
End Character
is a carriage return (equivalent to ASCII decimal character
number 13).
The system disables any checking of the checksum if the checksum char-
acter is equal to ?? (?? is equivalent to 2 ASCII 63 characters). This
makes testing by the programmer easy, but it is strongly recommended
that the integrity check is enabled in the final system.
Start
Character
Node address Command
Letter
Data Checksum End Character
“>” (ASCII deci-
mal character
62)
2 hex ASCII
characters (00
to FF)
(See Com-
mands Section
for list of com-
mands)
(ncharacters
- depends on
command)
2 hex ASCII
characters (sum
of all preced-
ing characters
except the “>”
character
Carriage return
(ASCII decimal
13)
NOTE
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