The MCS can provide “read only” interfaces to facilitate data to external databases, as specified on a project basis. In these cases, OPC UA can be specified and use of standard objects and concepts taken from the MDIS standard can be utilized based on project specific requirements.
To use the OPC UA interface as a “read only” interface it is recommended to that a Server be able to indicate that all writeable points (by definition have access restriction that denies write for all users and that no writeable ObjectType instance will exist in the address space. For all methods that allow writing, the user access rights should indicate not executable. The Server should be configurable to support this “read only” configuration. The server should not be able to be changed from this configuration without a restart.