Rockwell Automation 1785-CHBM ControlNet PLC-5 Hot Backup System User Manual - Manual (Page 57)

Publication 1785-UM024B-EN-P - January 2003
Using I/O in Your ControlNet Hot Backup System 4-3
Redundant connection parameters consist of:
• Input size
• Output size
• RPI
• Data Table Module configuration size
• Data Table Module configuration data (with the number of
words depending on the module type)
• any other connection-dependent configuration parameters
such as Fault Action and Idle Action. You configure these
parameters in RSNetWorx for ControlNet software.
You can use the Equivalence Checks - I/O Map Table feature to
make sure that all of the redundant connection parameters are
identical for both PLC-5 programmable controllers. This feature also
verifies that the input and output image addresses are the same and
that there are the same number of redundant connection on each
processor.
Changing I/O Configuration
Use the following procedure to insure that I/O module configuration
changes are accepted on both the primary and secondary PLC-5
programmable controllers. This procedure assumes that the primary
and secondary programmable controller’s RSLogix5 projects (.rsp files)
are properly associated with the same RSNetWorx project (.xc file).
Making I/O Configuration Changes to a Running Hot Backup
System
1. Place the secondary PLC-5 in Program mode.
2. For each connection that requires an I/O configuration change,
use RSNetWorx to inhibit the I/O connection for the PLC-5 in
Program mode. You must do this so that when the I/O
configuration changes are made to the primary PLC-5, the other
PLC-5 connection must be closed so that the primary’s new
connection can be established.
IMPORTANT
When you make I/O configuration changes to a
running application or process, you must place one
of the programmable controllers in Program mode.
However, the I/O configuration changes will
temporarily close and open the scheduled
connection. Thus, we recommend that you use the
procedure where both programmable controllers are
in program mode.