A lot of questions

[OSTC 14 V.122 User]

Hi since last Friday I am using a test OSCT, and now I have some questions:

1. I simulated a dive with "Diving Log". After that I delete the decompression data. Than the OSTC has shown actual depth 89m and dive time xx mins.(I can not remember exactly)
I was not able to exit this.
So I tried to delete the dive manual from the OSTC menue.
Result: completly frozen - I connected it to the USB interface and pushed reset - OSCT seems to be recovered
What did cause this 89m dive after the simulation and why did it freeze?

2. Active Gases
Example I do a dive to 40m with active Gases Air (0m), EAN50 (21m) and O2 (6m).
Does the OSTC automatically calculate the decompression time based on this 3 gases?
What will happen if I do not select the EAN 50 at 21m or O2 at 6m?
Will the calculation now be done/changed based on AIR as breathing gas?

Actually I did this dive yesterday and the decompression time did not change (I did not choose the active EAN50 from the Gas List).
I did a slow ascend, and arrived at 6m breathing Air, the OSCT has shown 6 minutes stop a 6m at this moment.
After about a minute I swithced to O2 and the decompression time did change by a minute only.
So again I am not sure if the OSTC took the O2 for the calculation before I switched at 6m or only at the moment I manualy switched for the Gas List.

3. Where can I change the wake up settings (250cm 5 seconds) in dive mode?

4. Will there be a version with a simulator/calculator where I can plan dives faster (not in real time)?
I would like to get a table as output, to compare for example with other programs, or just to write a backup runtime.

5. Does anybody has experience with the OSCT in depth ranges between 70-90 meters? Is the HW still reliable?

Regards,
Thomas / OSTC 14 V.122 User

[divinglog]

Hi Thomas

I'm the author of Diving Log so I can answer your question nr 1. There is no way to determine from a desktop program if the OSTC is in dive mode or surface mode. To reset the deco data the OSTC must be in surface mode, otherwise the command to reset the deco data is interpreted as depth value. This results in the 89m depth displayed on the OSTC, because it was still in dive simulation mode. When this happens, simply move the depth slider in the simulator again to 0m or press the "Stop Dive" button, then wait until the OSTC switches to surface mode, and then you can reset the deco data.

Kind regards,
Sven

[heinrichsweikamp]

> 2. Active Gases
> Example I do a dive to 40m with active Gases Air
> (0m), EAN50 (21m) and O2 (6m).
> Does the OSTC automatically calculate the
> decompression time based on this 3 gases?

The OSTC forecats deco sum based on the the active gases and presumes 10/min ascend speed.

> What will happen if I do not select the EAN 50 at
> 21m or O2 at 6m?

Stop time will be reduced slower.

> Will the calculation now be done/changed based on
> AIR as breathing gas?

Yes.

> Actually I did this dive yesterday and the
> decompression time did not change (I did not
> choose the active EAN50 from the Gas List).
> I did a slow ascend, and arrived at 6m breathing
> Air, the OSCT has shown 6 minutes stop a 6m at
> this moment.
> After about a minute I swithced to O2 and the
> decompression time did change by a minute only.
> So again I am not sure if the OSTC took the O2 for
> the calculation before I switched at 6m or only at
> the moment I manualy switched for the Gas List.

After passing 21m without switching to EAN50 the OSTC presumed the O2 switch at 6m.

> 3. Where can I change the wake up settings (250cm
> 5 seconds) in dive mode?

CF6: http://www.heinrichsweikamp.net/ostc/pm ... eitung.CF6

5sec. interval in Sleep is fixed to assure the sleepmode current is low enough.

> 4. Will there be a version with a
> simulator/calculator where I can plan dives faster
> (not in real time)?
> I would like to get a table as output, to compare
> for example with other programs, or just to write
> a backup runtime.

It's on our to-do list already: http://www.heinrichsweikamp.com/read.php?2,859

Cheers,
Matthias

[OSTC 14 V.122 User]

First of all thx for the answers. But still some things are not clear for me.

>The OSTC forecats deco sum based on the the active gases and presumes 10/min ascend speed.


Just simulated a dive with the following settings:

GF=10-85

active Gases 14/55(0m), 35/20 (36m), EAN50 (21m) and O2 (6m)

-descend to 80m in 5 minutes
-ascend at minute 19 with 10m/minute to first stop at 48m
-The total time to surface including all stops was about 92 minutes simulated with the OSTC

During the dive decompression time increased pretty far during the bottom time to 99 minutes ~~.
When I reached the 36m stop where the gas switch to 35/25 was planned the OSTC still has shown 99 minutes decompression time.
After I selected the 35/25 from the Gas List this changed immediately to 76 minutes.
Same at the 21m stop before the switch to EAN50 it was 70 minutes after 57 minutes.
Again the same at 6m OSTC has shown 42 minutes after the switch to O2 30 minutes.

So when looking at the simulated dive, I assume the OSTC does not calculate the decompression, by using the active gases.
Which is clear when the OSTC shows early during bottom time (at minute 15) 99 minutes decompression time and the time to surface was only 92 minutes.
So is it a bug or do I missunderstand something.


Also the show table function did not work well after the OSTC went to 99 decompression time (before it worked), still when decompression time was 30 minutes at the 6 m stop it has shown 0 for all stops beginning at "90 meters".

[OSTC 14 V.122 User]

So what I have to do, that the OSTC will forecast deco sum based on the the active gases and presumed 10/min ascend speed?
Or isn?t it possible?

[heinrichsweikamp]

If I simulate two different dives, 15min at 65m on 21/0
a) with O2 Deco at 6m
b) with Air Deco

I clearly see the difference of about 16minutes deco time at the end of the bottom time.

Make sure gases are configured as active and change-depths are fine. Disable any other gases. I use "ZH-L16 OC" but this should work with the "GF" modes, as well.

regards,
Matthias

[OSTC 14 V.122 User]

Just tried it two more times once with 1.26 and than again with 1.22.
Same result, OSTC does not forecast the deco sum based on the the active gases.

I deactivated only the air, below I wrote down the Gas List from Gas Setup - Gaslist it shows:

G1: 21/0 in 0m (less bright letters) comment: deactivated
G2: 14/55 in 0m (bright letters)
G3: *35/30 in 36m (bright letters)
G4: 50/0 in 21m (bright letters)
G5: 100/0 in 6m (bright letters)

Do you see any misstake?

[OSTC 14 V.122 User]

I repeated the test with ZH-L16 OC.
Same result, my OSTC does not forecast the deco sum based on the the active gases.

So is my device defect?
Or is it a user failure?
Failure of understanding?


There is another thing I detected, by misstake:
I forgot to set the last stop from 3 to 6m.
OK, no problem - I am in simulation mode only.
Than at the end of the 6m stop with O2, the OSTC has shown me "3m and 13 minutes stop time".
I decided to finish the deco on 6m and not to on 3m.
At the same time I was asking me, will the OSCT recalculate the deco based on staying on 6m and I took the time until the OSCT finished the decompression.
Result: 13 minutes - so it did not calculate based on actual depth?

[OSTC 14 V.122 User]

forgot the 6m 3m question - it not a bug

[OSTC 14 V.122 User]

forget

[heinrichsweikamp]

I have simulated some dives just yesterday and it worked as it should. Maybe you start with gas1 and set the deco gas to gas2 (That's what I did). Maybe there is still a bug in the decogas routine. I doubt that this is related to a hardware problem.

Regards,
Matthias

[wrobell]

OSTC 14 V.122 User Wrote:
-------------------------------------------------------
[...]
> During the dive decompression time increased
> pretty far during the bottom time to 99 minutes

i have noticed that as well (firmware ver. 1.26).
i am not sure if it counts as a bug or a thing we
have to live with.

that's only display, of course! decompression time
is calculated properly. if you have 120 minutes
of decompression at 3 meters, then ostc displays 99min
for 22 minutes. after 22 minutes display changes to
98 minutes and counts down as expected.

therefore, maximum _displayed_ decosum is 99m. this is
on main display. it applies to decompression plan
as well, i.e. max 99min is displayed for 3 meters
depth.

i find it bit strange though. for example, ostc
displays 160 minutes of no deco time at the begining
of dive simulation, so there is place to display
more than 99... 199? more?

regards,

w

[OSTC 14 V.122 User]

Well, I did some more test, and found that the OSTC does only forecast the deco sum based on the the active gases when:
Gas1= first gas
Gas2= deco gas

It does not work when I choose more than one active deco gas (e.g. ean50-21m and O2-6m).
So imho it?s a bug.
Can we expect a new firmware soon?

[heinrichsweikamp]

It's correct that the NDL time calculation is based on the selected gas only.
But as soon as deco is displayed deco gases are included in the calculation, no matter which gas# they have. I have tested this again and again today with different combinations.

A new 1.27 will be available soon, with several improvements for CCR users.

regards,
Matthias

[OSTC 14 V.122 User]

Did you make the test with one active deco gas only?
Or with more than one active deco gas?
Becuae with my test it did not work when I had more than one active deco gas (ean50-21m and O2-6m).