Annex C (informative) Guidelines for the usage of OPC UA for Devices as base for Companion Specifications
Deploying several Information Models based on this specification on the same device may lead to the situation, that the same Variable (e.g. the Property SerialNumber) for the same device is used in several places.
When the Property is the same, and the value of the Property is the same, it is recommended to avoid, that the value is managed in the Server in two different places (see Figure C.5, left). One solution is, that the two Variables reference the same internal memory managing the value (see Figure C.5, middle). Another solution is, that the Variable is only managed once in the Server, just referenced from different places (see Figure C.5, right). The solution using the same Node is the most optimized one in terms of memory consumption.
Figure C.5 – Options how to manage the same Variable