Rockwell Automation 1738 Assembly Connections for POINT I/O and ArmorPOINT I/O EtherNet/IP Adapters - Manual (Page 8)

Publication 1734-UM016A-EN-P - October 2010
2 Introduction
Data Headers
In the Target to Originator (T → O) direction, the adapter can be configured
to produce a status header for the connection. The header consists of an
8-byte bitmap, where bits 1 - 63 indicate the health of each of the 63 possible
backplane connections. This is similar to existing Rack Optimized
connections. A "1" indicates that a module is not connected or that slot is not
populated. A "0" indicates that the module is actively participating in the
connection. Currently, Bit 0 is reserved and should be ignored.
When the header is used, modules may be removed and reinserted without
breaking the I/O connection to the adapter. Modules not present or that are
failed are reflected in the status header.
If the optional status header is not included, the adapter cannot support RIUP
without breaking the I/O connection. If any one I/O module fails or is
removed, the adapter will break the connection to the connection originator.
Since no status is provided, this is the only way to reflect the fact that a
problem exists with the I/O modules on the backplane.
In the Originator to Target (O → T) direction the adapter supports the 4-byte
Run/Idle header. Sending a "1" indicates that the controller is in the Run mode
and that the adapter should apply the data that was just received. Sending a "0"
indicates that the controller is in program or idle mode and that the adapter
should put the I\O modules in their idle mode.
Listen Only Connections
Using an Assembly connection will allow multiple originators to consume data
from the POINT I/O system. However, only one owner of the connection is
permitted. That one owner will control all output devices present in the chassis
as well as the configuration of the connection.
Connection Points
The following table lists the connection points that are supported for the
different connection styles discussed.