Rockwell Automation 1785-Lx0C15 ControlNet PLC-5 Programmable Controllers User Manual - Manual (Page 76)

1785-UM022CEN-P - February 2008
3-2 Understanding the ControlNet System Software
Also, the ControlNet network requires that the entire network be
configured at one time to make sure all scheduled connections are
performed at their configured packet rates.
Two interdependencies exist between RSNetWorx and RSLogix 5
software:
• the I/O configuration utility invoked in RSLogix 5 software
• the ControlNet configuration information is created and saved in
RSNetWorx software, but is also saved and downloaded in
RSLogix 5 software
I/O Configuration Utility
The I/O configuration utility in RSLogix 5 software is used to
simplify the configuration of intelligent I/O modules. It is important
to understand the difference between I/O configuration over remote
I/O vs. I/O configuration over ControlNet:
• over remote I/O, the information displayed and entered in the
configuration applet is always read and written to the data table.
Thus, all of the I/O configuration functionality over remote I/O is
contained with the RSLogix 5 application.
• over ControlNet, the information displayed and entered in the
configuration applet is read and written to both the data table and
the RSNetWorx project (.xc) file.
The I/O configuration data must be read and written to the
RSNetWorx project (.xc) file so that the user can download the
I/O configuration data from RSNetWorx software. If the
RSNetWorx project (.xc) file was not updated with the I/O
configuration edits done within the I/O configuration utility, the
edits would be lost when that RSNetWorx project file was
downloaded.
You must configure the association to the RSNetWorx project (.xc)
file in RSLogix 5 software so that RSLogix 5 software knows which
RSNetWorx project (.xc) file to access the I/O configuration
information. You can do this within the Controller Properties window
in RSLogix 5 software. If you don’t use the I/O configuration utility
to edit or monitor ControlNet scheduled connections, the association
to the RSNetWorx project (.xc) file in RSLogix 5 software is
unnecessary.
Certain circumstances can cause the data table configuration
information to differ from what is stored in the RSNetWorx project
(.xc) file. This can occur when program logic is used to modify the
contents of the data table for purposes of reconfiguring a module via a
path other than the I/O configuration utility. If such “on the fly”
reconfiguration is necessary for your application, consider that
subsequently launching the I/O configuration utility applet will result
in outdated information being displayed, unless that information has
been imported into the RSNetWorx project (.xc) file.