Rockwell Automation Publication 1734-UM013C-EN-P - August 2010
113
Considerations When Replacing POINT Guard I/O Modules
Chapter
8
Why You Need to Manually Set the SNN
The examples above showed how the SNN is used to guarantee safety-connection
integrity after the system is operational. But the SNN is also used to guarantee
integrity on the initial download to the POINT Guard I/O module.
If a safety signature exists, then the POINT Guard I/O module must have a
proper SNN/node number identification that matches the module within the
RSLogix 5000 project, before it can receive its configuration. And to keep
integrity, the setting of the module’s SNN is
required
to be a manual action. This
manual action is to use the ‘set’ function on an out-of-box POINT Guard I/O
module.
Figure 20 - Setting the SNN with a GuardLogix Controller
Figure 21 - Setting the SNN with a SmartGuard Controller