RFC: PSCR dive plots: Part 2.

[Robert Helling]

Am 13.03.2018 um 12:25 schrieb Anton Lundin <glance at acc.umu.se>:

>> From subsurface point of view, it really doesn't matter if we represent
> a bailout as a gasswitch event or not. The problem with the gasswitch
> and setpoint change, is that it doesn't work for dives with po2 sensors
> or the SCR steady state approximation.
> 

Sorry, I don‘t get it. What is the problem with pO2 Sensors?

> 
> A setpoint change to 0 is sort of a clever hack which just works for
> planed/setpoint-only CCR dives, and not for CCR dives with po2-sensors,
> or SCR dives.
> 
> 
> I'd suggest we clean that up into some bailout sematics which works for
> both SCR and CCR code, with or without o2 sensors.
> 
> 
> If we implement that as a divemode switching event, a gaschange event
> with some special flags, i don't really have a opinion until i see a
> real suggestion. Nothing says we can't have a gaschange event which
> switches to the same gas as we're currently using...

You could always interpret „gas switch“ not as „switch of gas in cylinder“ but as „switch of breathing gas“ as that what PSCR divers experience when going from the loop to OC.

I would say, the main difference is to make „PSCR mode“ not a global thing for a dive but more local in time. Note that this is already the case for „CCR mode“: We have set point that can change over time with 0 indicating OC and „CCR mode“ in a more strict sense (as in the combo box) is simply a dive that has at least at some part non-zero set-point (but we don’t use that to determine the breathing gas at any moment).

Does that make sense?

Robert