How do we handle stop all

[DominicOram]

There is a usecase for a stop button that, regardless of whether a plan is running, will run some (beamline specific) stop code.

Setting BlueAPI to aborting can handle some of this but not all as it will do nothing if BlueAPI is already running.

There are a few options to handle this:

• Make the UI do it (this is what we have done in waffle as a stop gap but I don't like it i15-1: Make stop all close the fast shutter atlas#202 (review))
• Give a hook in BlueAPI stop that runs regardless of if a plan is running
• Create a new service

Acceptance Criteria

• A decision is made on how we handle stop all

[Mark-Booth]

Remember that Blueapi is not a safety system.

Only a big red physical button is truly an Emergency Stop, so we should never refer to any software button as an "Emergency Stop" or "E-Stop" because it isn't. This is why in GDA we have a "Stop All" button, to make that distinction.

Don't get me started on how unprofessional it is to mix in the word "Panic" here!

[fajinyuan]

with regard to
Give a hook in BlueAPI stop that runs regardless of if a plan is running
My guess is you would like the BlueAPI stop to

1. stop currently running plan
2. configurable for beamline to add/configure actions to stop other devices
3. not like the bad GDA 'Stop All' command which call stop on every Stoppables, but only call stop on listed devices or actions.
   In RunEngine there are 3 different kind stops
   RE.abort()
   RE.stop()
   RE.halt()
   which of these you want this issue's stop to call?

Bluesky supports resuming a paused plan from its last checkpoint. It also distinguishes stop, abort, and halt: stop performs cleanup and records success, abort performs cleanup and records abortion, while halt does not give the plan an opportunity to clean up.

[DominicOram]

not like the bad GDA 'Stop All' command which call stop on every Stoppables, but only call stop on listed devices or actions.

I think the default Bluesky behaviour is to call stop on any devices that have been staged in the plan. I wouldn't mind if the behaviour of BlueAPI was to call stop on all devices it knows about, we would just have to be careful that's clean.

I think in this case it's probably an abort. We want to do cleanup e.g. close shutters and stop motors but it's shouldn't result in a successful end to a plan.