OC1 Sampling Rate and Log book capacity

[BjFaeTorphins]

I purchased an OC1 at Dive2009 at the weekend and I'm working my way through the manual trying to get to gribs with all of the whells and bissles on my new toy.

Page 69 of the manual describes how the sampling rate at which "information is stored for download to the associated PC Interface Program". This can be varied from 2 to 60 seconds i.e. a x30 range.

Page 54 describes how 1-24 dives are stored and when 24 dives are stored the oldest is deleted and the dive just completed is stored in it's place.

Why is the number of dives that are retained not dependent upon the sampling rate?

 

[bperrybap]

It is confusing.
What isn't obvious or really described is that Oceanic/Aeris (Pelagic) computers maintain 2 separate logbooks.
The logbook you see and can flip through on the LCD, which is just summary information, and the logbook you can download which has the profile information.
It is the logbook/history you see on the LCD that has the small fixed sized number of entries.
The download logbook is much larger and the number of dives in it depends on the sample rate and the bottom time for the dives as the dive entry and the profile data share the same memory.

The nice thing about having the 2 logbooks is that even if you fill up or even overflow the download logbook with a small number of dives because maybe the sampling rate is very short or the dives have long bottom times, the fixed sized LCD onboard logbook remains unaffected so you can always look at the fixed amount of dives that are in the on board logbook/history. There is no profile information for the on board LCD divelog and you can't download the dives in it with the Oceanlog s/w, but you can still see them on the LCD.

So in practical terms. Here is an example.
Note: each model is slightly different and the amount of LCD logbook entries and download logbook memory varies.

I have an AtmosAI. This model has a 24 dive LCD logbook.
If I set my sample rate to 15 seconds and do 1 hour dives, the download logbook will overflow at 17 dives.
This means I can never have more than around 16 one hour dives in the download logbook
So while there will only be 16 dives that can downloaded, there will still be 24 dives in the LCD logbook that
I can review on the dive computer LCD.

Likewise, if I set my sample time to 30 seconds and still did the 1 hour dives,
the download logbook would not overflow until about 32 dives.
So while the on board LCD would have only 24 dives, I would be able to download 32 dives.

Hope that helps clear it up.

--- bill

 

[BjFaeTorphins]

As you say it's not obvious.

I would have never guessed that there were two independent log books.

Thanks for the comprehensive answer.