68 Rockwell Automation Publication 1769-UM022C-EN-P - June 2018
Chapter 5 Communicate Over Networks
Automatic Versus Manual
For typical users, the automatic assignment of an SNN is sufficient. However,
manual manipulation of the SNN is required if the following is true:
• Safety consumed tags are used.
• The project consumes safety input data from a module whose
configuration is owned by some other device.
• A safety project is copied to another hardware installation within the
same routable CIP Safety system.
Changing the Safety Network Number (SNN)
Before changing the SNN you must do the following:
• If the project is safety-locked, then you must unlock it.
See Safety-lock the Controller
on page 158.
• If a safety task signature exists, then you must delete it.
See Delete the Safety Task Signature
on page 161.
Change the SNN of the Controller
1. In the Controller Organizer, right-click the controller and choose
Properties.
2. On the General tab of the Controller Properties dialog box, click to
the right of the safety network number to open the Safety Network
Number dialog box.