Command Message Format - Ametek Dycor CG1000-RTP User Manual

Command Message Format

Start
Character
"
>"(Ascii
character
3E Hex)
characters
A-2 | Dycor CG1000-RTP Oxygen Analyzer
The command message format is as follows:
Node Command
Address Letter
2 hex (see commands
Ascii section for list
characters - of commands)
(00 to FF)
Where:
The Start Character is the greater-than character (">," which is ASCII 3E hex).
The Node Address is from 00 to FF and is replaced as two hex ASCII char-
acters. Each controller has a unique node address (see the "Communica-
tion/Node Address" section in the Setup Key chapter for help on specify-
ing node addresses for controllers).
The maximum number of controllers that can be connected on the

network is 32.
NOTE
The Command Letter is from ASCII A-Z (upper case only).
Data is a string of characters whose meaning depends on the command
and where the number of characters returned also depends on the com-
mand. Limit is 20 characters.
The Checksum is the sum of all the preceding characters (excluding the >
character) - modulo 256.
The End Character is a carriage return (equivalent to ASCII decimal char-
acter number 13).
The system disables on checking of the checksum if the checksum char-

acter is equal to ?? (?? is equivalent to 2 ASCII 3F hex characters).
This makes testing by the programmer easy but it is strongly recom-
NOTE
mended that the integrity check is enables in the final system.
Data Checksum
(n characters 2 hex Ascii
depends on characters
command) (sum of all
preceding
except the ">"
character)
End Character
carriage return
(Ascii character
10d Hex)