CRYOSMS: Improve comms issues

[KathrynBaker]

Issue Description

As someone using this system I keep getting mismatches on the comms, which can make the system unstable, I want it to be stable and reliable for confidence of use.

How & Where?

It can be seen on all the systems using these PSUs that every so often (ranging from once every few days, to getting stuck in it for hours on end) the comms gets out of step in some way. This can be either getting surplus data through, or missing some characters, both can be seen looking through the logs on LET and HIFI Cryomag in December.

Reproducible (Yes/No)?

Unsure, but it should be possible to add this to the emulator and tests as specific issues to generate and respond to.

Additional Information

Recommendations to fix this:

• Make sure that the emulator and tests are happy on your system, tests all pass, running in DEVSIM allows you to interact with the device sensibly
• Reproduce the errors in the emulator, see them in an IOC when running in DEVSIM
• Adjust the protocol file by ignoring surplus characters and see if that helps for surplus characters
• Adjust the protocol file to be more flexible for missing characters
• Consider finding a way to flush the output buffer before sending values if there is time.

Acceptance Criteria

• The recommendations are worked through
• Every response in the emulator can send extra or fewer characters than expected
• Every response is tested for both extra and fewer characters
• Changes to the protocol file are checked in if they work
• There are tasks to patch this changed protocol file to both LET and HIFI-CRYOMAG if it works

How to Review

_{Before making a PR...}

• Provide verbose instructions for the reviewer to test that your changes work and fix the issue
• Describe if/how you have implemented testing for this issue
• Provide screenshots of the feature to help the reviewer if relevant

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

...

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

[GRyall]

see also https://teams.microsoft.com/l/message/19:8f40434ddbc744ec8f73bc7d240169c4@thread.skype/1765795447175?tenantId=3f66361c-a87e-4158-8f61-99e82db3cac8&groupId=d9946ec3-a454-424f-b673-5ffcb9f9ade0&parentMessageId=1765795447175&teamName=IBEX%20Developers&channelName=support-issues&createdTime=1765795447175