Rockwell Automation 2711E PanelBuilder 1400e Modbus Communications - Manual (Page 52)

6–15 Defining Tags
Publication 2711E-6.12 – August 1997
Addressing Syntax for Devices Using 6-digit Addressing:
Reference Operations Addressing Syntax
3 word
read-only 3wwwww where
wwwww = word offset 00001 to 65535 (decimal).
No bit offsets are supported.
4 word
read and write 4wwwww where
wwwww = word offset 00001 to 65535 (decimal).
No bit offsets are supported.
Important: Because block tags with References 1 or 3 are read
only, they can only be assigned to display objects (e.g.
Numeric Data Display). An error will be generated
when you validate the application if a tag with
Reference 1 or 3 has been assigned to an input object.
For more information about types of objects, see
Chapter 9, “Creating Objects,” in the PanelBuilder
1400e Configuration Software for Windows User
Manual, Publication Number 2711E-819.
The data source determines where a tag’s data comes from. Tags
defined for a Modbus application must specify the Device data
source.
Note: DDE and Memory data sources are only used by RSView.
For a Modbus application, the tag’s reference determines whether it
is a read or a write tag:
Reference Number Operation
0 read and write
1 read only
3 read only
4 read and write
Note: The exception is for digital tags, for which Reference 4 is
read only.
Important: Because tags with References 1 or 3 are read-only, they
can only be assigned to display objects (e.g. Numeric
Data Display). An error will be generated when you
validate the application if a tag with Reference 1 or 3
has been assigned to an input object. For more
information about types of objects, see Chapter 9,
“Creating Objects,” in the PanelBuilder 1400e
Configuration Software for Windows User Manual,
Publication Number 2711E-819.
Specifying a Data Source
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