Optimizing Produced Tags; Connections For Consumed Tags - Allen-Bradley ControlLogix User Manual

Optimizing produced tags

Each produced tag requires connections that can be used for other controller
operations. To minimize the of produced tags, and the number of required
connections, consider grouping data into an array or a user-defined structure
and producing only that array or structure, as long as the array or structure is
not larger than 500 bytes.
Compare the following two examples to see how a user-defined data type
(structure) reduces the number of connections required to produce the same
data.
Example 1: Producing data as individual tags
Produced Tag Data Type
height DINT
width DINT
weight REAL
W_flag DINT
L_flag DINT
Example 2: Producing data as a user-defined data type (structure)
Produced Tag Data Type
Load_Info User-defined structure of:
height (DINT)
width (DINT)
weight (REAL)
W_flag (DINT)
L_flag (DINT)

Connections for consumed tags

Each consumed tag requires one connection for the controller that is
consuming the tag.
Allocating Communication Connections
Connection Number of
for the Tag Consumers
1 3
1 3
1 3
1 3
1 3
Connection Number of
for the Tag Consumers Total Connections
1 3
1756-6.5.3 - December 1999
A-7
Total Connections
4
4
4
4
4
Total: 20 connections
4
Total: 4 connections