How to use the Checksum feature
F-2 ADAM 4000 Series User's Manual
F.1 Checksum Enable/Disable
To enable configuration of a module’s checksum feature, its INIT*
terminal should be shorted to its GND terminal, after which the module
should be rebooted. The checksum feature is enabled by setting bit 6 of the
data format/checksum parameter to 1. To disable the checksum, set the
parameter to 0. Remember that when using the checksum feature, it should
always be enabled for all connected devices including the host computer.
The checksum is represented by a 2-character ASCII hexadecimal format
and is transmitted just prior to the carriage return. The checksum equals the
modulo-256 (100h) sum of all the ASCII values in the command preceding
the checksum. If the checksum in a command is missing or incorrect the
module will not respond.
Example 1
The following is an example of an Analog Data In command and response
when the checksum is enabled:
Command: #0588(CR)
Response: +3.56719D(CR)
The input value at the module at address 05h is +3.5671 V. (The date
format is engineering units.) The command checksum (88h) is the sum of
the ASCII values of the following characters: #, 0, and 5. The response
checksum (9Dh) is the sum of the ASCII values of the following charac-
ters: “>” “+” “3” “.” “5” “6” “7” and “1” .
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