Allen-Bradley controllogix 1756-L55M12, User Manual

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Publication 1756-UM001G-EN-P - January 2007
48 Manage Controller Communication
Produce and Consume
(Interlock) Data
The controller supports the ability to produce (broadcast) and
consume (receive) system-shared tags over ControlNet or EtherNet/IP
networks. Produced and consumed tags each require connections.
Over a ControlNet network, produced and consumed tags are
scheduled connections.
Tag Types
For two controllers to share produced or consumed tags, both must
be attached to the same network. You cannot bridge produced and
consumed tags over two networks.
The number of available connections limits the number of tags that
can be produced or consumed. If the controller uses all of its
connections for I/O and communication devices, no connections are
left for produced and consumed tags.
Available Connections
Additional Resources
For additional information, consult these publications:
•
Logix5000 Controllers Common Procedures Programming
Manual, publication 1756-PM001
•
Logix5000 Controllers Design Considerations Reference Manual,
publication 1756-RM094
Tag Type Description
Produced A produced tag lets other controllers to consume the tag, which means that a
controller can receive the tag data from another controller. The producing controller
uses one connection for the produced tag and one connection for each consumer. The
controller’s communication device uses one connection for each consumer.
As you increase the number of controllers that can consume a produced tag, you also
reduce the number of connections the controller and communication device have
available for other operations, such as communication and I/O.
Consumed Each consumed tag requires one connection for the controller that is consuming the
tag. The controller’s communication device uses one connection for each consumer.
Device Supported Connections
ControlLogix controller 250
•
1756-ENBT module
•
1756-EWEB module
128
•
1756-CNB module
•
1756-CNBR module
64
48 is the recommended maximum.