Rockwell Automation AADvance Controller Configuration Guide - Manual (Page 182)

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8-12 Document: 553633
ICSTT-RM405f-EN-P
Issue 07
Configuration Guide (AADvance Controller)
 Each produced tag uses (1 + number of active consumers) connections in the
controller if any of the consumers are multicast. If all consumers are unicast, then
the produce tag only uses (number of active consumers) connections. Unicast is
only available over Ethernet for V16 and later controllers.
 Each Consumed tag requires one connection in the controller.
For the local communications (bridge) modules:
 One connection is used for each consumer of each produced tag.
 One connection will be used for each consumed tag.
For Ethernet networks, the number of produced multicast addresses must also be
considered. Use the following rules to calculate the number of produced multicast
addresses used by an Ethernet module. Note that any Ethernet module is limited to
producing 32 multicast addresses:
 Each tag produced though an Ethernet communication module will use 1 multicast
address, regardless of the number of consumers it has through the module.
 There is no multicast limit for consumed tags.
Notes
1) If a produce tag is consumed by only Ethernet unicast consumers, the controller
will use only the number of connections equal to the active consumers, but will
still use (1 + defined consumers) in download calculations. If any of the consumers
are not unicast, then the controller will use ( 1+ number of active consumers)
connections. The unicast option is available only for Ethernet and only if the both
the producing and consuming controller are v16 or higher. Unicast is not available
on ControlNet.
2) A produce tag that has one or more consumers as non-unicast through a
local Ethernet bridge module (for example, an ENBT module) will use up one
multicast address in the ENBT. The ENBT is limited to 32 multicast
addresses. Therefore there is a maximum of 32 produced tags that have one or
more consumers as non-unicast from a single ENBT.
3) An Ethernet bridge module that is in the rack with a controller consuming a
connection does not use up one of its available 32 multicast connections.
4) ControlNet bridge modules do not have any limit other than the limit of their total
available connections.
Example 1
Consider a controller that has one local ENBT and 20 produced tags, two consumers
each.
 If none of the produced tags are unicast, then (20 x (2 + 1)) = 60 connections will
be used in the controller. (20 x 2) = 40 connections will be used in the ENBT. 20
produced tags means 20 multicast addresses will be used by the ENBT.
 If 10 of the produced tags are strictly unicast, and the other 10 are not, then there
will be 50 connections used in the controller ((10 x (2+1)) + (10 x 2)), 40 used in
the ENBT, and 10 multicast addresses used in the ENBT.