Model comparison. Closest to Petrel?

[tantram]

Hey all,

Lost my faithful Perdix in a few hundred feet today. Needless to say, I don't think she will be finding her way home. I'm still a few beers short of getting over it. I have been eyeing up the OSTCs for awhile now, because I find the concept interesting and appealing.

Coming from a Perdix, which model computer would feel the most at home for me? I'm having a hard time determining the differences between each of the models.

Diving multi-gas side mount.

Thank you for any feedback.

[Ralph]

Hi,

to start with the easy things: you will need a tech Version, which supports up to 5 OC trimix gases, provides full blown deco calculation functions and also CCR / pSCR diving with additional 5 trimix diluent gases if you will go that way any time in the future.
The next question you have to decide is if you will favour the OSTC 4 or one of the OSTC 2 generation computers (OSTC 2, Plus or cR). The OSTC 4 is the newest one and compared to the 2's familiy has a more powerfull processor and a higher resolution display. But its Firmware is not open source, as it's name may suggest. That means like with your faithful Perdix, you don't know exactly what the software really does in detail as only the manufacturer knows the code. The 2's Generation OSTCs are open source, so if you are or like to get familiar with C code and Microchip PIC Assembler, you can read the complete software and see what it does in any diving situation... Practically, the 2's familiy code is at the moment of writing a little bit ahead of functionalities compared to the OSTC4. Saying the 2' family code means the 2, the Plus and the cR are all running the same Firmware.
So what's the differences within the 2's family OSTCs? In simple terms: the cR provides an interface for connecting external oxygen sensors, so it is the prime choice for rebreather divers wanting to hook their computer to the loop. The Plus and the 2 can also be used for rebreather diving, but with fixed (user selected) setpoints "only". The Plus has a user-changable battery, the 2 has a built-in battery. No worries: the computers run for ages on a single charge! For the rest of the technical details, see the manufacturers web page...

Cheers,
Ralph

[tantram]

Thank you for the great reply. That answered a lot of questions I had.

A few follow ups:

Are the 2's going to stop being produced in favor of the 4?

Is the only different between the 2 and the 2 plus the case?

At this point I am leaning towards the 2 plus tech and the 4. I have no plans to dive rebreather, so I don't need the oxygen sensor port. Gas keeps me alive just fine:-).

[Ralph]

Well, the question how long the 2's will stay in production can only be answered by Matthias, given he will disclose the HeinrichsWeikamp product strategy... But make your own guessing: the OSTC 2 just received in the beginning of 2017 a case facelift. And when you look at the source code repository at https://bitbucket.org/heinrichsweikamp/ ... ommits/all you will see how alive the 2's family firmware is.

The 2 and the Plus differ in the battery used. The Plus can take a rechargeable or an AA and will run on the rechargeable approx 30 hours. Pro: in lack of a charger, you can fit an AA one-way. Con: you have an opening with a seal. The 2 has a build in battery which runs approx. 60 hours per charge. Pro: no opening, no seal, no chance for any flooding. Con: if the battery breaks down in ?? years, that's it.

[heinrichsweikamp]

Hi,

OSTC2 was introduced less then a year ago. It will stay in production for at least another two years. As well as the OSTC Plus. Guaranteed.

regards,
Matthias

[tantram]

Great, thanks

Looks like you just sold me a new computer!