Rockwell Automation 1785-CHBM ControlNet PLC-5 Hot Backup System User Manual - Manual (Page 52)

Publication 1785-UM024B-EN-P - January 2003
3-26 Installing and Configuring Your ControlNet PLC-5 Backup System
Requalification of Dual
Primary Processors You can select to requalify a PLC-5C Hot Backup processor if dual
primary processors exist. This will avoid a major fault. Additionally,
this feature increases the availability of a qualified backup system if
communication is broken between the two PLC-5 processors.
To set the requalification of dual primary PLC-5s, check the
Requalification Enabled box in the lower left corner:
PLC-5 Editing
Considerations There are some considerations you should be aware of when editing
the processor of a ControlNet PLC-5 backup system. Editing, in this
context, refers to any changes you make to the program files, data
table structure, force tables, and status file. Edits that you make to one
PLC-5 are not automatically transferred to the other PLC-5. Thus, if
you wish for edits to apply to both PLC-5s, you must take the steps to
make that happen.
Most simply, you can ensure the changes are made to both PLC-5s by
manually making those changes yourself. If your edits are small, this
might be the fastest and easiest solution. However, if you have made
large amounts of editing changes to one PLC-5, it may be difficult and
time consuming to make all the same editing changes to the other
PLC-5. This section describes another method for doing this.
IMPORTANT
When a processor requalifies, it transitions out of
Run mode into Program mode during qualification
and data table crossload - and then transitions back
into Run mode.