Rockwell Automation 2711 PANELBUILDER SOFTWARE USER MANUAL - Manual (Page 218)

Information and Alarm Windows
Chapter 7
7-10
if BCD data type is specified, the address assignment will be a
contiguous bit string of 4, 8 or 12 bits (that is, 1, 2, or 3 digits). For
496 messages you would need 12 bits
if bit is specified, the address assignment will always be a
contiguous bit string containing from 1 to 496 bits. For 496
messages you would need 496 bits
IMPORTANT: The data type, together with the number of bits,
determines the maximum number of messages that can be triggered from
the PLC controller. See the following section on Address Assignment and
PLC Information and Alarm Message Triggering for more information.
Update Address updates the application file with the values entered for
the Data Type through to the Number of Bits. The new address is
displayed at the top of the menu. If you make a mistake entering a new
address, an error message will appear when you choose Update Address.
View Address Map shows you the address map of the bits allocated so
far for all the objects, windows and PLC Control Options.
Delete Address removes the existing address from the file.
Quit closes the Window Control Address menu and returns you to the
Information Window menu.
Address Assignment and PLC Information Message Triggering
How the PLC controller triggers messages depends on the data type that is
selected. The data types are discussed below.
Binary Data Type
If binary data type is specified, the address assignment will be a contiguous
bit string containing from one to 16 bits. The bit string can be positioned
anywhere within the same PLC rack (even crossing word boundaries) by
designating the desired start bit (the default is zero which is the typical
choice). Together, the number of bits and the data type dictate the number
of messages you can trigger for the Information window.
BCD Data Type
If you specify BCD data type, the address assignment will be a contiguous
string of 4, 8 or 12 bits (that is, 1, 2, or 3 digits.)