Rockwell Automation 1732DS-IB8 User Manual page 85

Configure Modules in RSNetWorx for DeviceNet Software 81
If successfully reset, the following text appears in the message
area. Note the exclamation point has changed to a minus sign
on the 1791DS module. The minus sign typically means the
node is missing; but this is not the case. Disregard the minus
sign and continue.
5. Right-click the 1791DS module and select Properties to see the
Safety Network Number dialog.
Publication 1791DS-UM001H-EN-P - April 2009