Surface Interval start...

[cheeseandjamsandwich]

It seems like my OSTC 2N starts timing my surface intervals from the time i get out of the water, back on to the boat, rather than when i surface...
My backup Suunto is always giving the correct SI time...
Sometimes we can wait a little while for the boat to come an pick us up so there's quite a few minutes difference.

Is this by design? Or a bug?
Can this be fixed?

TIA
Rich

-----------------------------------------------------
EDIT as of 2014-01-16:
Just to make it clear...
It turns out that the Safety Stop reported is timed from when the OSTC exits dive mode (time-out set by CF02), rather than from when the diver surfaces and starts breathing air at surface pressure. Hence it's 240 seconds, 4 minutes out.
This thread is reporting this little bug and asking for it to be corrected, giving a few detail to justify it.
Enjoy!
-----------------------------------------------------

[scubatinoo]

Rich, do you know CustomFunctions? If not, have a look here:
file.php?2,file=403,filename=OSTC_Custo ... N_V270.pdf

Please refer to CF02... Because OSTC's don't have wet-contacts all things must be done by pressure and/or timer...

[cheeseandjamsandwich]

Be it pressure or wet contacts, it should be able to start the SI correctly. The Suuntos use both pressure threshold and wet contacts, but use the pressure to know when it's on the surface, correct?

Ah, So is the OSTC starting the SI from after the CF02 delay is reached?

So to correct this, when the OSTC times-out of dive-mode, after CF02 seconds (240s = 4 mins) and enters surface mode, it should already display a surface interval of CF02 seconds (240s), i.e. 4 minutes.

[scubatinoo]

Honestly i don't see any advantage of this suggestion. Why do you care about +4 Minutes SI? if it comes to a critical point it is safer to have 4 more Minutes Surface Intervall than having 4 Minutes missing...

[Laurie_the_Knot]

If this suggestion were implemented it would bring it in line with most, if not all, dive computers in common use.

When I'm on a dive trip and I'm about to do a second dive and I'm asked for my surface interval I have to add the surface delay setting, CF02, to the displayed surface interval on the surface screen. If I don't do this little sum my surface interval time is invariably different from my buddy's.

I'm all for the implementation of this suggestion.

[cheeseandjamsandwich]

scubatinoo Wrote:
-------------------------------------------------------
> Honestly i don't see any advantage of this
> suggestion. Why do you care about +4 Minutes SI?
> if it comes to a critical point it is safer to
> have 4 more Minutes Surface Intervall than having
> 4 Minutes missing...
?

The Surface Interval is the time you've been on the surface. If it's going to report it, it might as well be the correct value.

I guess you've not been on a boat that does 2 dive trips.

Just because you don't see the need for a particular feature, it doesn't mean that it's not necessary/useful for other users.

...

Cheers Laurie!


R.

[heinrichsweikamp]

Hi,

As others wrote: The surface interval starts when the unit is in surface mode again (After CF02 timed out). Honestly, we're not going to change that.

Cheers,
Matthias

[Bumlerd]

heinrichsweikamp Wrote:
-------------------------------------------------------
> Hi,
>
> As others wrote: The surface interval starts when
> the unit is in surface mode again (After CF02
> timed out). Honestly, we're not going to change
> that.
>
> Cheers,
> Matthias

+ 1

Michael

[scubatinoo]

cheeseandjamsandwich Wrote:
-------------------------------------------------------
> The Surface Interval is the time you've been on
> the surface. If it's going to report it, it might
> as well be the correct value.
>
> I guess you've not been on a boat that does 2 dive
> trips.

Please come down. I'm often doing 2 (sometimes even 3 dives)
a day, but then i care about hours between the dives and not
about a few minutes... Feel free to lower the CF02 to what you
think will suit your needs.

[cheeseandjamsandwich]

Ok, i set CF02 to 0 seconds to see what affect it had on my second dive just now, and I'm glad I had my D6i as backup!

If CF02 = 0 the OSTC will reset back to surface mode every time the dive time reaches 1:00 (one minute). Then it immediately switches back into dive mode... This repeats throughout the dive...

So i landed up logging 51 dives!

I think this is a bug? Or perhaps the minimum value should be 1 second?

[heinrichsweikamp]

0 won't work. And anything below 30sec isn't useful IMHO.

Regards,
Matthias

[scubatinoo]

Matthias, is it possible to limit Custom Functions to a certain range of values? Obviously it is possible to set a value which it is not working... Just to prevent users from doing stupid things

[cheeseandjamsandwich]

heinrichsweikamp Wrote:
-------------------------------------------------------
> 0 won't work. And anything below 30sec isn't
> useful IMHO.
>
> Regards,
> Matthias
OK
I didn't read the Custom Function Description doc, that has a 'Suggested Range' of 120-240
Perhaps this Document should list hard limits where they exist? (wasn't this documented somewhere? In the old CF manual?)

[swissdiving]

[quote=tinoo]
Matthias, is it possible to limit Custom Functions to a certain range of values? Obviously it is possible to set a value which it is not working... Just to prevent users from doing stupid things
[/quote]


OSTC3!

[scubatinoo]

@swissdiving, in this case this answer would be right:

swissdiving Wrote:
-------------------------------------------------------
> RTFM


-D

[cheeseandjamsandwich]

scubatinoo Wrote:
-------------------------------------------------------
> @swissdiving, in this case this answer would be
> right:
>
> swissdiving Wrote:
> --------------------------------------------------
> -----
> > RTFM
>
>
> -D

Spooky, i was actually watching The IT Crowd last night too!
[img]http://itshirts.files.wordpress.com/200 ... 48s230.png[/img]

[cheeseandjamsandwich]

heinrichsweikamp Wrote:
-------------------------------------------------------
> Hi,
>
> As others wrote: The surface interval starts when
> the unit is in surface mode again (After CF02
> timed out). Honestly, we're not going to change
> that.
>
> Cheers,
> Matthias
Anyhoo...

Back on-topic...

I find it strange that this 'feature' is not going to be fixed.
I'm guessing it's just an oversight in programming that wasn't picked up until now perhaps. As many divers don't seem to care much about the reported SI.

But for some of us, it does matter.
I'm out instructing/guiding on a dive boat that does a 2 tank trip in the morning and a 2 tank trip in the afternoon. We have to have a 1 hour minimum surface interval between dives, and the boat captain/boss wants us to be prompt in and out of the water so that everything runs on time... this is just how it is.

But the fact remains, we now know that the Surface Interval the the OSTC reports is actually the time it says plus a number minutes set by the user for the screen to change... Yes it's 'only' 4 minutes... But it is The Wrong Value.

The Surface Interval is the time The Diver has been on the surface, off-gassing... It's got nothing to do with the computer they are wearing.


I used to be a mechanical design engineer, so i really appreciate the right functionality, with a good design, a solidly made product (very rare these days) and attention to detail is everything... That's what make truly great products.
These are the reasons why i invested in the OSTC.

[Bardass]

so if you are mechanical design engineer, you can't ignore that decompression is not a science

do you really think that +-4 minutes of SI change anything about decompression ?
If so, then add 4+ to you surface interval.
but
are you sure that your Suunto D6 is safe with deepstops ?
are you sure that RGBM is a safe algorithm ?
are you sure that your GF paramaters are the good one ?
are you sure that any algorithm i safe with 4 dives in a day ?

[cheeseandjamsandwich]

Bardass Wrote:
-------------------------------------------------------
> so if you are mechanical design engineer, you
> can't ignore that decompression is not a science
>
> do you really think that +-4 minutes of SI change
> anything about decompression ?
> If so, then add 4+ to you surface interval.
> but
> are you sure that your Suunto D6 is safe with
> deepstops ?
> are you sure that RGBM is a safe algorithm ?
> are you sure that your GF paramaters are the good
> one ?
> are you sure that any algorithm i safe with 4
> dives in a day ?

Granted.


But we've found something in the firmware that is wrong. Needlessly wrong.

The OSTC is already timing the Surface Interval... you can just use the CF02 timer and keep reporting that... Minimal code editing i'm guessing.

Like i said, attention to detail.

[scubatinoo]

Bardass Wrote:
-------------------------------------------------------
> are you sure that any algorithm is safe with 4
> dives in a day ?

Good point! Especially if this is done over a period of several days...


cheeseandjamsandwich Wrote:
-------------------------------------------------------
> But we've found something in the firmware that is wrong. Needlessly wrong.

We should rather blame the lazy logbook pages...

[Dahab Boris]

Ding dong... Great post, love the name BTW "cheeseandjamsandwich"
Not sure about Cheese and Jam on a sarnie.. but hey ho

[cheeseandjamsandwich]

heinrichsweikamp Wrote:
-------------------------------------------------------
> Hi,
>
> As others wrote: The surface interval starts when
> the unit is in surface mode again (After CF02
> timed out). Honestly, we're not going to change
> that.
>
> Cheers,
> Matthias

The answer i and others were perhaps hoping for was something like:
[pre]"Ah yes, it appears that the surface interval shown is indeed incorrect, we didn't notice this when coding it.
We'll add it to the to-do list and correct the bug in a future firmware release."[/pre]

Then this issue would be fixed and finished with.

[Bumlerd]

Hi

@ cheeseandjamsandwich


And the answer I and several others were hoping for when Mathias wrote:
"Honestly, we're not going to change that" was : "ok, then I will live with that or I will develop my own fw, and not continue this tread" and pronto
"> Then this issue would be fixed and finished with"

Michael

OSTC 2N 3933

[cheeseandjamsandwich]

Bumlerd Wrote:
-------------------------------------------------------
> Hi
>
> @ cheeseandjamsandwich
>
>
> And the answer I and several others were hoping
> for when Mathias wrote:
> "Honestly, we're not going to change that" was :
> "ok, then I will live with that or I will develop
> my own fw, and not continue this tread" and pronto
>
> "> Then this issue would be fixed and finished
> with"
>
> Michael
>
> OSTC 2N 3933


Why would you hope for that answer? (to not fix it) Details please.

[cheeseandjamsandwich]

So if the depth reading on the OSTC was actually measuring the depth below the 1m default threshold set by CF00, would you live with this? Knowing it's wrong, but hey, it doesn't matter that much, as its the time at depth that dictates deco more than the depth itself... I very much doubt it.

This would be almost exactly the same bug as with the Surface Interval.