Rockwell Automation 1755-OF8 GuardPLC Controller Systems User Manual

Page 257

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Publication 1753-UM001C-EN-P - March 2010

257

Use the GuardPLC Controller as a Scanner Chapter 20

6. Configure the Connection Properties for the I/O module, using

the Connection tab on the Connection Properties dialog box.

In a produce/consume system, modules multicast data, meaning
that multiple modules can receive the same data at the same
time from a single module. When you choose Connection
Name, in this dialog box, you must choose whether to establish
an owner or listen-only relationship with the module. An owner
connection is any connection that does not include Listen Only
in its Connection Name.

Property

Description

Connection
Name

Some modules do not support all of the possible EtherNet/IP connection types: Exclusive Owner, Input Only, and Listen
Only. The Connection Name pulldown menu contains only the connection types supported by the selected module.

Exclusive
Owner

When the exclusive owner type is used, output assemblies can be written. Only one exclusive owner
connection is allowed to connect to a single output assembly. Multiple Exclusive Owner connections can
be made to input only modules. Any module that contains output assemblies can have only one Exclusive
Owner.

Input Only

An input only connection lets input assemblies be exported to one or more consumers. Another connection
request to the same input connection can be made if the same data size and requested packet rate are
specified. All Input Only connections are independent of one another. When one of the connections is
closed, the others remain open.

Listen Only

With listen only connections, input assemblies are sent to one or more consumers. For a listen-only
connection to be established, an exclusive owner or input only connection with multicast must already
exist. All the subsequent Listen Only connections depend upon the owner connection. When an owner
connection is closed, all subsequent Listen Only connections are also closed.

Requested
Packet Interval
(RPI)

Enter the Requested Packet Interval (RPI) in ms. The RPI specifies the period at which data updates over a connection.
The RPI is entered in 1 ms increments. The RPI specified for the GuardPLC controller can be as little as 1 ms. However,
the GuardPLC controller will not produce or consume data with a rate less than 2 ms, because this is the tick of the
GuardPLC communication module. This limits the minimum RPI to 2 ms.

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