hwOS Tech: 2.97 released

[Ralph]

Hi,

fully got your point. Sure the OSTC needs to be able to handle the same gas configured several times, for whatever reason. Next step will be program code review to see if duplicated gases do cause a problem or if there is something else. This will take a little bit of time...

-R.

[DennisA]

Ralph Wrote:
-------------------------------------------------------
> Hi Dennis,
>[....]
>
> safe flying,
> Ralph


Thank you for a very thorough answer!

[dwhitlow]

Hi,

There are a lot of new features since I last did a full explore of the settings and I have a few observations, a couple a questions and a few suggestions:

Observations
------------

1. OSTC cR still enters USB mode when plugged into charger or computer. Release notes say this should no longer happen.

2. 'Simulator' > 'Calculator Setup' shows 'CCR Setpoint:' when configured for OC diving

3. 'use AGf' is selectable in 'Simulator' > 'Calculator Setup' when disabled in 'Deco Seup'

Questions:
---------

4) What is the usage of the values for 'Saturation:' and 'Desaturation:' in Deco Parameters?

5) What is the usage of 'Loop %O2 max.:'?

Features
--------

6. As gas consumption is an owner constant it might be better placed in 'Settings'

7. To place all cylinder characteristics in one place, 'Tank Sizes' and 'Tank Pressure' might be better added to the 'OC Gas List' page

8. In simulator results, if calculated Gas Usage: exceeds gas configured (from Tank Size, Tank Pressure and gas consumption) a warning * might be helpful

9. Planning dives
------------------

This would be made very much easier with the changes below:

9.1 Values for 'Bot. Depth' and 'Bot. Time' values to be stored until reset (by 9.2)

9.2 'Calculator Setup' could have new option 'Reset Calculator' to clear the effects of 9.1

9.3 In 'Simulator' > 'Calculator Setup' add new link to 'OC Gas List'

9.4 In 'Simulator' > 'Calculator Setup' add new link 'CCR Setup

9.5 In 'Simulator' > 'Calculator Setup' add new link 'Deco Setup

[heinrichsweikamp]

Hi,

> 1. OSTC cR still enters USB mode when plugged into
> charger or computer. Release notes say this
> should no longer happen.

Only from the menu. If the OSTC cR is in the main screen - it will not enter the USB mode automatically.

> 2. 'Simulator' > 'Calculator Setup' shows 'CCR
> Setpoint:' when configured for OC diving

That's true, in OC this would not be required but it's easier to implement this way.

> 3. 'use AGf' is selectable in 'Simulator' >
> 'Calculator Setup' when disabled in 'Deco Seup'

Same as above.


> 4) What is the usage of the values for
> 'Saturation:' and 'Desaturation:' in Deco
> Parameters?

These two parameters influence the saturation and desaturation process in the Bühlmann model. They can be used to compensate for cold water or physical fitness. In non-GF mode these parameters are the only way to influence the deco conservatism. In GF mode these are optional to the GF pair.

> 5) What is the usage of 'Loop %O2 max.:'?

When flushing with O2 your loop will never reach 100% O2 due to N2/He outgasing and remaining diluent in the scrubber. This parameter takes care of this and can be used to increase the accuracy of the deco algorithm here.

> 6. As gas consumption is an owner constant it
> might be better placed in 'Settings'
>
> 7. To place all cylinder characteristics in one
> place, 'Tank Sizes' and 'Tank Pressure' might be
> better added to the 'OC Gas List' page
>
> 8. In simulator results, if calculated Gas Usage:
> exceeds gas configured (from Tank Size, Tank
> Pressure and gas consumption) a warning * might be
> helpful

Ok.

> 9. Planning dives
> ------------------
>
> This would be made very much easier with the
> changes below:
>
> 9.1 Values for 'Bot. Depth' and 'Bot. Time' values
> to be stored until reset (by 9.2)
>
> 9.2 'Calculator Setup' could have new option
> 'Reset Calculator' to clear the effects of 9.1
>
> 9.3 In 'Simulator' > 'Calculator Setup' add new
> link to 'OC Gas List'
>
> 9.4 In 'Simulator' > 'Calculator Setup' add new
> link 'CCR Setup
>
> 9.5 In 'Simulator' > 'Calculator Setup' add new
> link 'Deco Setup

Another good suggestion. Due to the fact that we just finished the new manual it's more something for a future version here...

regards,
Matthias

[Ralph]

Hello ClaudeDive,

please excuse the time it took to finialise the aswering of your post regarding gas consumption calculations. I re-run your example:

GF 10/85
SAC 15l/min for both bottom and deco
the last stop i set to 3m
the ppO2 limits i set to 1,4 / 1,6 bar

Tissues clean (Deco Reset via Settings Menu)

G1 Travel 50/15, 7l
G2 First 10/70, 24l
G3 Deco 25/45, 7l
G4 Deco 50/15, 7l
G5 Deco Nx80, 11l


Deco-Calculator (Simulator Menu): 120 m for 11m -> Results:
-----------------------------------------------------------

TTS 141 min, first stop at 84 m

G1 0 l
G2 3897 l
G3 1830 l
G4 1116 l (33 l less than you reported)
G5 1632 l (19 l more than you reported)


Simulated Dive (via Simulator Menu): 120 m -> Results:
------------------------------------------------------

In the Deco-Calculator, the deco schedule and the gas needs are calculated
once for exactly the point in time set as bottom time. In the (real) divemode
the tissues are recomputed every 2 seconds and the deco schedule and gas Needs
are repetitive computed, but not on a 2 seconds interval because one
calculation run takes longer than 2 seconds. You can actually see how long one
run takes when using the deco calculator, it's the time when "calculating" is
shown. As the OSTC has to do several more things when in real dive mode, the
deco calculations are given about half a second every second, so one
calculation run spans over several seconds. The more stops a particular dive
requires, the more time it takes and the TTS and gas needs do only get updated
every couple or even ten's couple of seconds. Therefor i intercepted the
results not exactly at 11 minutes of dive time but at the point in time where
results with a TTS of 141 minutes got published to the display. In my case
this was at 11 minutes and 38 seconds of dive time, but this does vary e.g.
when using the +5' simulator function because it aborts and restarts
computations and thus interfers with the calculation cycle timing.

This is what i got:

10/70: 73 bar x 24 l = 1752 l Deco Calculator: 3897 l -> the Deco Calculator computes for the full dive, in divemode (simulation) only the gas needed for the ascent is calculated, hence the difference
25/45: 261 bar x 7 l = 1827 l ------------> 1830 l -> nearby perfect match, delta due to some seconds of diff in time when the inputs to the deco calculation were sampled.
50/15: 164 bar x 7 l = 1148 l ------------> 1116 l -> ditto
Nx80: 146 bar x 11 l = 1606 l ------------> 1632 l -> same


Can you reproduce similar results?

Best Regards,
Ralph

[Ralph]

Hi dwhitlow,

thanks for your suggestions 6. - 9. !

I checked the space that is left in the different menus and found it quite hard to either squeeze some items into the settings menu and/or keep the overviews e.g. for the tank sizes and pressures. With the currrent menu layout, all settings that influence gas consumption and fTTS/bailout planning are under one roof, i.e. the "2nd Deco Plan" menu.

9.1/9.2 wouldn't be needed if 9.3-9.5 get realised as one doesn't need to leave the simulator sub-menu any more, which triggers the reset of depth and bottom time. But there is an inherent danger that users may play with the gas, CCR and deco settings from off the simulator menu, thinking it just affects the simulator "playpen" environment, whereby it in deed also affects the next real dive. So there are pros and cons...

Best Regards,
Ralph

[ClaudeDive]

Hi Ralph,

Thank you for your results, I would have liked to get results close to yours, but my results are still close to my previous results,

I give you back my complete setup: OSTC3 # 2430> v2.97 latest version 01.03.2018
Depth 120 m - Time 11 mn
GF 10/85 - SD 100/100
SAC 15l / mn for both stocking and deco
Fixed ascent speed: 10 m / mn

Last stop at 3m
PpO2 limits at 1.4 / 1.6 bar
Clean fabrics, no diving for more than 72 hours

- G1: Travel: 50/15> 7 L - 200 bar> Without Depth of Change
- G2: First: 10/70> 24 L - 200 bar> Bottom Gas
- G3: Deco1: 25/45> 7 L - 200 bar> Depth of Change 54 m
- G4: Deco2: 50/15> 7 L - 200 bar> Depth of Change 21 m
- G5: Deco3: Nx80> 11 L - 200 bar> Depth of Change 9 m


Deco-Calculator (Simulator Menu): 120m for 11mn >> Results:
- ------------------------------------------------- - --------
TTS 140 min, first stop 84 m
G1: 50/15> 0 L
G2: 10/70> 3897 L> Same as my previous results
G3: 25/45> 1830 L> Same as my previous results
G4: 50/15> 1111 L> 38L less than my previous results
G5: Nx80> 1613 L> Same as my previous results

Diving simulation (via the simulator menu): 120 m >> Results:
-------------- ------------------------------------ ----
I let my OSTC3 run the time without using the simulator function +5 '
Here is what I got: for a dive time of 11:03
 TTS 127 min - First stop at 81 m

G2: 10/70: 132 bar x 24 L = 3168 L >> Deco Calculator: 3897 L
G3: 25/45: 349 bar x 7 L = 2443 L >> Deco Calculator: 1830 L >> Delta: 613 L
G4: 50/15: 212 bar x 7 L = 1484 L >> Deco Calculator: 1111 L >> Delta: 373 L
G5: Nx80: 191 bar x 11 L = 2101 L >> Deco Calculator: 1613 L >> Delta: 488 L

[img]http://forum.heinrichsweikamp.com/file. ... 33403a.jpg[/img]

The results are rather different between the Deco-calculator and the Simulator and would require in the case of a real dive to reduce the time at the bottom in view of pressures "Gas Need" displayed on the screen to not exceed the pressures available Tanks
Note that for a real dive it would be necessary to use for G3: a Tank 11 L

Regards, Claude

[ClaudeDive]

Sorry, message broadcast several times by mistake

[ClaudeDive]

Sorry, message broadcast several times by mistake

[Clownfish]

I did two more dives today and can confirm that the Safety Stop countdown works okay in normal screen but not in the alternate screen. Yes, it does appear that the countdown of two seconds takes two seconds, but it is very annoying to watch that one takes half a second and the next one one and a half seconds. Hopefully it can be fixed.

[Ralph]

Hi Michael,

the "hooping" of the safety stop countdown in alternative screen layout is confirmed and a fix is already in final testing. The reason for the "hopping" is that currently the countdown is written to the display after the deco calculations, but as the deco calculations have a varying runtime they impose a jitter on the countdown output timing. Output will be done before deco calculations in the next firmware and thus be stable in timing then. Thanks for your feedback anyhow!!

Best Regards,
Ralph

[Ralph]

Hello Claude,

what puzzles me most is that you get so much consumption on the 10/70 bottom gas, because the deco calculator computes the whole dive whereas in divemode only the ascent needs are calculated. So there should be a delta in the 10/70 figures by the amount of gas the 11 minutes on 120 meters already took. There must be something different between the way you execute the test and i do, but currently i have no clue what it is...

BR
Ralph

[ClaudeDive]

Hi Ralph,

When I do the test in dive mode in the simulator, I parameter 120m and I start the simulator, I do not touch anything and I let the diving time go to 11 minutes and I note the parameters avec a photo as you see it on my message, it's as simple as that ... I don't understand me either ...

For G2 : 10/70 to 11 mn of diving one has about 12 mn of rise and stop up to 57m for a bottom consumption of approximately 1495 L to 15 L / mn atmospheric is a need in gas of 1495/24 L = about 65 bar and so no 132bar as displayed for the 10/70

Regards

Claude

[algo]

@hw: when will the new manuals be available on your homepage? I have some questions about the new functions and i am sure, they are all answered there, so no need to ask here...

Alex

[heinrichsweikamp]

New hwOS TECH manual in German is online: https://heinrichsweikamp.com/service/manuals

English translation is in work.

regards,
Matthias

[Ralph]

Hi Claude,

i may have found the explanation why we have different gas needs results: what is your setting at Deco Setup / 2nd Deco Plan / fTTS/fB/O ? Mine is zero which means gas needs are calculated in dive mode under the assumption of an immediate ascent. When this setting is > 0, the ascent & deco calculation assumes you are staying for that number of minutes longer at current depth before you start your ascent. This way one can add in extra time at depth for e.g. scrambling the team mates, sending up a surface marker, etc.

Calculating the deco schedule for 120m / 11 minutes in the deco calculator (via simulator menu) with your gases and GF setting takes about 25 seconds (i used a stopwatch to get this figure). This is the time the OSTC2 family computers need when calculating this dive profile at 100% CPU utilisation. When in real dive mode, only 50% CPU time is given to deco calculations, the rest is used for updating the display, writing log data to EEPROM etc. So one computation cycle at 120 m of depth and at 11 minutes into the dive takes approx. 50 seconds - meaning your deco results for runtime == 11 minutes will be available approx. 40...50 seconds later, i.e. at runtime 11 minutes and say 45 seconds. This is for the case fTTS is set to 0.
If fTTS is set to > 0, the OSTC actually computes two complete ascent & deco schedules: one that drives the values for first stop, ascent time, ceiling etc. based on immediate ascent and a second plan (hence the menu name '2nd Deco Plan') that drives the fTTS time and the gas needs. In the above example both plans take about 40..50 seconds to compute and they are computed in alternation. So if fTTS is enabled (>0), the gas needs for runtime == 11 minutes will become available somewhere between approx. 45 to 90 seconds later (i.e. at 11:45 ... 12:30 min RT).

Hope this solves the puzzle!

Best Regards,
Ralph

[ClaudeDive]

Hi Ralph,

Yes ! Thank you for your insight,

So with the setting: fTTS / fB / O: 0' >> I had previously fTTS / fB / O: 5 '
Clean fabrics, no diving for more than 72 hours
And the other settings unchanged we have:

- G1: Travel: 50/15> 7 L - 200 bar> Without Depth of Change
- G2: First: 10/70> 24 L - 200 bar> Bottom Gas
- G3: Deco1: 25/45> 7 L - 200 bar> Depth of Change 54 m
- G4: Deco2: 50/15> 7 L - 200 bar> Depth of Change 21 m
- G5: Deco3: Nx80> 11 L - 200 bar> Depth of Change 9 m


Deco-Calculator (Simulator Menu): 120m for 11mn >> Results:
- ------------------------------------------------- - --------
TTS 138 mn, first stop 84 m
G1: 50/15> 0 L
G2: 10/70> 3897 L> Same as my previous results
G3: 25/45> 1830 L> Same as my previous results
G4: 50/15> 1111 L> Same as my previous results
G5: Nx80> 1569 L> 44L less than my previous results

Diving simulation (via the simulator menu): 120 m >> Results:
-------------- ------------------------------------ ----
I let my OSTC3 run the time without using the simulator function +5 '
Here is what I got: for a dive time of 11:00
TTS 132 mn - First stop at 81 m

G2: 10/70: 72 bar x 24 L = 1728 L + 11' x 13b x 15L/mn = 2145 L = 3873 L >> Deco Calculator: 3897 L >> OK
G3: 25/45: 251 bar x 7 L = 1757 L >> Deco Calculator: 1830 L >> Delta: 73 L >> OK
G4: 50/15: 152 bar x 7 L = 1064 L >> Deco Calculator: 1111 L >> Delta: 47 L >> OK
G5: Nx80: 134 bar x 11 L = 1474 L >> Deco Calculator: 1569 L >> Delta: 95 L >> OK

So Ralph with the setting fTTS / fB / O: 0 'we are now OK,

The fTTS / fB / O: 3 'or 5' setting is generally not a problem for air diving between 0 and 60m

But if we want to keep interest of thid setting for trimix diving it is good to keep the current display provided you have the fTTS / fB / O: 0 'setting for normal diving continuity,

But it would be very useful to be able to switch on a display fTTS / fB / O: 1 'or 2' or 3 'for the case or one wants to check the possibility of prolonging the dive of 1' or 2 'or 3'

This function could be called "aTTS"

This possibility could be set up in the same way that one can during the dive switch from GF to aGF

Without this possibility to switch from fTTS / fB / O: 0 'to fTTS / fB / O: 1' or 2 'if we use a different setting of 0' we have alarming information "Gas Need" see very alarming during diving,

Hoping that this can be useful,

Regards, Claude

[Ralph]

Oh dear, one day we will need to find out how to attach a 1 GB USB stick to the OSTC computers in order to store all the configuration settings and options thinkable...

But glad to hear we have found the cause for the discrepancies between your and my calculation run results!!

Have a nice day,
Ralph

[ClaudeDive]

Hi Ralph,

Great !

With the setting fTTS / fB / O: 0 'I currently have the possibility during the trimix dive to have the info "gas Need" during the normal continuity of my dive programmed at 11' in our example,

But if for some reason I have to extend my trimix dive by 1 'or 2' or 3 'I have no way of knowing "gas Need" info for a fTTS / fB / O setting: 1' or 2 'or 3 ', which is important information for the safety of my dive,

I can ? Or I can't extend my trimix dive safely?

This is the meaning of my proposition on my previous message, with an alternative type function "aTTS" as we have it with "GF" & "aGF"

In the current offer, I have two possibilities:

1) Setting fTTS / fB / O: 0 ' But I don't know what are my possibilities beyond my current dive time,

2) Setting fTTS / fB / O: 1 'or 2' or 3 '
And in this case the info "Gas Need" may be very worrying, and requires me to safely reduce my dive time before have reached the expected dive time,

Hoping to be taken into account and to be useful,

Regard, Claude

[Ralph]

Hello Claude,

the fTTS function has two areas of application it was intended for:

1) when riding criss-cross the no-deco - deco border on stepwise ascents, you can see if your current depths are still increasing your deco, if they are kind of neutral to it (TTS doesn't change), or if you are decoing (TTS decreases).

2) The other field of application is the gas needs warning. Initialy developed for CCR/pSCR bailout needs prediction, it is available in OC mode, too. As it takes on deep/long dives with a high number of deco stops about 1 to 2 minutes before both, the normal plan and 2nd deco plan values get updated round-robin, it's not really practical to switch fTTS delay times under water - you have to wait too long for the results to derive a decision aka "well, i can stay 2 minutes longer" from, simply because they are over when you get this result...

Especially for dives like in the above sample calculation, i personally would strongly advice to adhere to the old rule "plan your dive and dive your plan". The fTTS / fB/O computation is really made to always figure in a gas reserve that hopefully never ever is needed. Speaking from own experiance, last year i had the case that we were on the edge of ascent into the blue water from of a wreak under current conditions and i was seconds before sending up my SMB (holding all SMB gear in my hands), when my dive mates regulator suddenly freeflowed. This is one of the situations i like to always have 1 to 2 minutes of reserves in my calculations...

Save diving to all of you,
Ralph


PS: in CCR and pSCR mode, when activating bailout, fTTS calculation (i.e. whole 2nd deco plan calculation) is disabled and the gas needs are calculated within the normal plan calculations to a) give the figures for the "now situation" and b) speed up deco data updates in this emergency Situation.

[ClaudeDive]

Thank you Ralph,

Well understood the meaning of your answer, of course that at 120 m we do everything to respect the dive plan, the border is narrow ...

But at lesser depths, the border is a little wider and can make it possible to consider staying 1 'or 2' more ...

In the near future the next generations of OSTC will certainly have more powerful processors that will allow to obtain instant deco calculations to give us this type of information live!

Regards, Claude

[Clownfish]

Not sure if this is related to new firmware, but since I loaded it, my compass has not worked properly. I have recalibrated it a number of times (I have now done about 12 dives since installing) but it has only worked correctly on the first dive after the recalibration.

Coincidence?

[Ralph]

Hi Michael,

after the last update, mine worked better... Coincidence? Likely! There was an update in compass sensor gain control, differentiating between different hardware versions of the sensors built into the OSTCs over the years. That's a Topic for Matthias from HeinrichsWeikamp, I'll give him a trigger to check that.

BR
Ralph

[heinrichsweikamp]

Hi,

There was no change in the actual code itself so I'm sure this is not working better or worse then before. What's changed is the calibration routine which now uses an automatic gain control for the magnetometer. This basically should increase sensitivity (More values for one revolution). What's displayed for the Cal X, Cal Y and CAL Z values in the compass menu?

regards,
Matthias

[Clownfish]

X: -24
Y: 1312
Z: 470