Some devices / components itself are built in a modular way. For example, an IPC usually is shown as a unit within the system, but internally it uses standardized modules like a PCIe plug-in card or a 2,5” solid state drive. It may be worthwhile to be able to name these modules for maintenance purposes.

Figure 55 – Modular Devices with OPC UA References

In the example above, we see an industrial computer together with its connectors that are named such that it is possible to show the connectivity within the MV system later on.

In this example, the IPC offers connectors for power supply, video output (Display Port and HDMI), a serial interface and two Ethernet Ports.

Most of these interfaces are built into the IPC (soldered to the mainboard). Therefore, we see HasContainedComponent references pointing from the ComputingDevice to the PhysicalInterface nodes which expresses a “this is an integral part of something” relation.

As in the Image sensor example above, it is up to you to decide what internal components are useful to be included in the model. If an internal component has meaningful maintenance information that may be monitored without the context of the device it belongs to, it may be worth it to add that component to the system model.

An example for that could be a hard disk or solid-state drive which usually provides health information (SMART / GPL) often including a prediction if this drive will fail in the near future.

You may incorporate this SMART data into the health information of the device containing the drive, but for a client it could be easier to have a standardized browse point (folder) where to find all SMART data from all drives no matter in which component they are located.

(Note: Part2 does not include a definition for mass storage devices as there are already standards for that)

Another example could be cooling fans. Instead of distributing their maintenance information over the components they are mounted to, it could make monitoring easier to have them all in one folder.

Figure 56 – Modular Devices with OPC UA References

Again, choosing different reference types can be used to give more information on the service task that has to be expected if a part needs to be replaced.

In this example, the Image sensor has an externally attached fan which, by definition of that reference type, should not be hard to detach.

The IPC has a built in CPU fan, which by definition of that reference type Is not designed for easy replacement and it has a contained case fan which is in between those, maybe like a fan cassette of a rack device that may easily be replaced from the outside without the need to dismantle the IPC.