Ametek Thermox 2000 ATEX Series User Manual page 164

A-2 | Thermox Series 2000 WDG-HPII / HPIIC - ATEX
The Start Character is the greater than character (">", which is ASCII 3E
hex).
The Node Address is from 00-FF, and is represented as two hex ASCII
characters. Each sensor has a unique node address. Note, however, that
the maximum number of sensors that can be connected on the network is
32 and for the gateway, we have limited the valid addresses from 01-32.
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
> character) - modulo 256 or the characters "??" (?? is equivalent to 2
ASCII 3F hex characters).
The End Character is a carriage return (equivalent to ASCII character 0D
hex).
The system disables any checking of the checksum if the checksum
character is equal to ?? (?? is equivalent to 2 ASCII 3FH hex charac-
ters). This makes testing by the programmer easy, but it is strongly
recommended that the integrity check be enabled in the final system.
NOTE