Rockwell Automation 1756-L6x_L7x ControlLogix System User Manual - Manual (Page 120)

120 Rockwell Automation Publication 1756-UM001O-EN-P - October 2014
Chapter 7 Manage Controller Communication
Figure 21 - Illustration of Produced and Consumed Tags
The system-shared tags are explained in Table 26 .
For two controllers to share produced or consumed tags, the controllers must be
attached to the same network. You cannot bridge produced and consumed tags
over two networks.
Produced and consumed tags use connections of the controller and the
communication modules being used. For a ControlNet network, produced and
consumed tags use scheduled connections.
Connection Requirements of a Produced or Consumed Tag
Produced and consumed tags each require connections. As you increase the
number of controllers that can consume a produced tag, you also reduce the
number of connections the controller has available for other operations, like
communication and I/O.
Table 26 - Produced and Consumed Tag Definitions
Tag Definition
Produced tag A tag that a controller makes available for use by other controllers. Multiple controllers
can simultaneously consume (receive) the data. A produced tag sends its data to one or
more consumed tags (consumers) without using logic.
Consumed tag A tag that receives the data of a produced tag. The data type of the consumed tag must
match the data type (including any array dimensions) of the produced tag. The RPI of
the consumed tag determines the period at which the data updates.
IMPORTANT If a consumed-tag connection fails, the other tags being consumed from that
remote controller stop receiving new data.
Controller_2
Controller_3
Controller_4
Consumed Tag
Consumed Tag
Consumed Tag
Controller_1
Produced Tag