Figure 3-6 Using Checksum Protocol - Honeywell UDC2300 Product Manual

3.7 Checksum Protocol (for Data Security),
Success or failure
Figure 3-6 Using Checksum Protocol
Host
30 RS422/485 ASCII Communications Option Product Manual
After receiving a request that uses checksum protocol, the UDC calculates
the checksum of the characters received and compares this to the
hexadecimal number stated in the checksum field. Depending on whether
the checksums agree, the UDC returns either the "success" or "failure"
response. Figure 3-6 indicates what happens when checksum protocol
is used.
Request that includes
Checksum protocol
"Failure" response
"Success" response
Computer uses
protocol to check
response messages
Continued
UDC
Controller uses
protocol to check
request messages
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