OPCUA: The MAPS implementation needs few corrections

[Chsudeepta]

Issue Description

As an instrument engineer on MAPS I am seeing some wrong information described below. Currently the interface is not using any authentication which also needs to be implemented.

Here are some of the issues:
1. The relay information is wrong or misleading. See the image below.

A) The section in red is really about the Relay switches and they could be associated to any sensor, but here the sensors are hardcoded.
B) The Relay status shown as LED in the OPI can't handle the status which comes as String.
C) It will be useful to show the name of sensors along with the Pressure information for ready identification.

2. There is no authentication. It is mandated to have certificate based authentication as implemented for MERLIN and MUONS,
3. The DB records should be ideally generated without any hard-coding for namespace. The template used can be improved.

How & Where?

The issue came up while discussing the implementation of MERLIN OPCUA.

_{If not applicable, write "Not applicable"}

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Reproducible (Yes/No)?

Yes
_{If yes, describe step-by-step how to reproduce the issue.}

1. Run the OPCUA IOC with MAPS OPCUA_01.cmd file in configuration path: \instrument\Settings\config<Machine_Name>\configurations\opcua
2. In the Device Screens perspective add MAPS_Vaccum_System as Screen
3. Check the Relay switch details towards the bottom of each TPG tab.

Additional Information

_{What else do I need to know before starting?}

• See the screen below. It is already implemented for MERLIN and pointing the MAPS containing OPI to have its tabs connected to the same file, namely BASE_OPC_TPG.OPI would take care of the OPI level changes

• The authentication mechanism is already implemented in MERLIN and described here: https://github.com/ISISComputingGroup/ibex_developers_manual/blob/opcua_certs/doc/specific_iocs/plcs/OPCUA.md
• There may be minor changes needed in the DB records. Aamir can be helpful here to extract any structural change. But most of the PVs will work as is.

_{See our Git Workflow.}

Acceptance Criteria

_{What is the acceptance criteria of this ticket? What should the reviewer expect to be complete?}

• MAPS OPCUA implementation should show correct Relay Switch information
• The certificate based authentication should work
• The template files should be improved, new PVs added and namespace should be externalized.

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How to Review

_{To the reviewer: Make sure to update submodules!}
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