Table 3-4 Request Message Fields Definitions - Honeywell UDC2300 Product Manual

3.4 Request Messages,
Request message
field selections
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Continued
Table 3-4 is a list of selections for the request message fields and their
definitions.
Table 3-4 Request Message Fields Definitions
Selection
Station Address A two-digit device address – from 01 to 99 – that
identifies the specific controller you are addressing. You
must assign a unique station address to each controller
on the link.
See "Preparing the Controller for Communications" in this
manual. A UDC will not respond to address 0 since the
address results in a disconnect.
Protocol Field A four-digit number that selects whether or not you are
going to use a Checksum Protocol (for increased data
security) with your message exchange.
• 4204 selects Checksum Protocol
• 0204 ignores Checksum Protocol
Any sequence utilizing other than 4 or 0 in the first digit
results in an error with an error message returned.
UDC State and A hexadecimal number that determines what state you
Mode want the UDC to be in (monitor or slave) and the mode of
operation desired (manual or automatic). You can also
change the controller setpoint from Local setpoint to
Remote setpoint or vice-versa.
Any change made in UDC State or Control mode will
not be indicated in the response until the next
transaction.
Protocol Class and A hexadecimal number that allows you to do a Loopback
Operation Code or do a READ, WRITE, or READY transaction.
Definition
– see "Checksum Protocol"
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