OSTC4 not calculating Deco correctly. Possible Bug?

OSTC running hwOS4 Firmware
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Divert
Posts: 18
Joined: Friday 24. May 2024, 00:06

OSTC4 not calculating Deco correctly. Possible Bug?

Post by Divert »

Hello, in the process of knowing my OSTC4 better I decided to plan a dive, first in Subsurface and then in OSTC4 to compare.
The dive:
50m depth with 60 minutes bottom time.
Algorithm VPM-B +3
Gas 1 Air
Gas2 NX50

Subsurface: 10 different Stops!
Subsurfaceplan.jpg
The OSTC Plan with same parameters:
Gases:

Settings1:
settings1.jpg
Settings 2:
Settings 2.jpg
Last edited by Divert on Thursday 20. June 2024, 08:49, edited 1 time in total.
Divert
Posts: 18
Joined: Friday 24. May 2024, 00:06

Re: OSTC4 not calculating Deco correctly. Possible Bug?

Post by Divert »

Continuation....

OSTC Plan: ONLY 3 Stops!
PlanVPM.jpg
I started the simulation to understand what would happen and some strange things started to happen: for example
Sin parada a 15m.jpg
No stop at 15m. Why???

On another run 40m with bottom time of 40 minutes The OSTC4 mandated a deco stop shallower than the calculated Ceiling!!!!
Techo Arriba de Parada.jpg
As I startet to get nervous, I switched to Bühlmann ZH-L16C and ran the 40m 40' simulation. where a full deco stop disappeared wile still on the bottom time!!! I took a video for you to watch the behavior. https://nube.buceoluegoexisto.com/s/GsbsiHG2imd4M2G

Please advice.

Humberto
swissdiving
Posts: 819
Joined: Saturday 30. July 2011, 07:30

Re: OSTC4 not calculating Deco correctly. Possible Bug?

Post by swissdiving »

I very much doubt therecis a bug. Diving the ostc4 for years now not having a problem with deco....
Cheers,

Hansjoerg

--> 2N ¦ 2201 / 3892
--> OSTC4 ¦ 257 / 392 / 424 / 647/1324 Fischer

RTFM
Divert
Posts: 18
Joined: Friday 24. May 2024, 00:06

Re: OSTC4 not calculating Deco correctly. Possible Bug?

Post by Divert »

swissdiving wrote: Thursday 20. June 2024, 17:24 I very much doubt therecis a bug. Diving the ostc4 for years now not having a problem with deco....
This is so nice to hear! Do you dive also with VPM?

I am so willing to find that I am wrong about this. I love the computer and the support from Matthias and Ralph
swissdiving
Posts: 819
Joined: Saturday 30. July 2011, 07:30

Re: OSTC4 not calculating Deco correctly. Possible Bug?

Post by swissdiving »

VPM and Bühlmann.
Cheers,

Hansjoerg

--> 2N ¦ 2201 / 3892
--> OSTC4 ¦ 257 / 392 / 424 / 647/1324 Fischer

RTFM
heinrichsweikamp
Posts: 4393
Joined: Sunday 13. May 2007, 18:07

Re: OSTC4 not calculating Deco correctly. Possible Bug?

Post by heinrichsweikamp »

Thanks for the detailed report, we'll have a look into this. There will be some improvements in the next releases with the VPM (The time for 9m is entered in the time for 6m and then overwritten for the list display) the total ascent time is correct, also the shown "next stop". A bug, yes: But not critical. We'll fix this.

regards,
Matthias
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