In CSLS safety installations, the Local Safety Networks (LSNs) are assigned to Global Safety Network (GSN) domains. LSNBs connect to both the LSN and the GSN. By default, all Local Safety Network Bridges (LSNBs) are assigned to DOMAIN1, and it is not necessary to create additional domains unless others are needed to create a logical organization. You can move LSNBs to different domains; refer to the topic Move an LSNB to a different GSN domain.
Domains exist in the hierarchy under the Global Safety Network. As long as two LSNBs are on the GSN, they can be included in the same domain.
DeltaV supports up to 16 GSN domains.
Secure parameters are specific to the LSN where they are created. When a reference to a secure parameter is created in a different local safety network, the database creates the mapping of the parameter and reference.
The source LSNB publishes that secure parameter to the GSN. From there, the LSNBs that use the secure parameter receive it and publish it on their local safety networks. Secure parameters referenced only within the parameter's source local safety network are not collected by the LSNB. If the reference is within the same GSN domain as the secure parameter, a domain mapping is created. If the reference is in a different GSN domain, a system mapping is created.
The database maps the secure parameters for each publisher automatically to optimize publisher usage, but it does not shift existing secure parameter mapping when one or more are deleted. This is to avoid forcing a re-download of referencing logic solvers for unchanged secure parameters.
Not every LSNB has to publish data. LSNBs can be receive-only. There is no limit on how many LSNBs can listen to the GSN on a domain and transmit the received secure data on their LSNs.