strobe interaction with VT3?

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hi,
I am very interested in the VT3 yet have seen several references to flash strobes interfering with the wireless connection from the pressure gauge... mostly the interruption of the signal for several seconds. Admittedly the VT3 has not been directly referenced but I dont want to make a $1k investment to still carry an extra hose and gauge!..

a) Does the VT3 safely recover from strobe interaction like this?

b) In the event of such a loss of signal and (hopefully timely) recovery to indicate pressure, are the air consumption rates & air time remaining calculations still valid? (or do they get reset or corrupted?)

thanks in advance!
 
Hi,
Oceanic addresses this in the owner's manual for the VT3 which can be found on their website in PDF format.

VT3 Operating Manual - 12-2705-r01.pdf

The information is on page 77 and 78. If you can't open PDF files, this is what it says

Page 77

"Link Interruption Underwater

During a dive, you may at times move the VT3 out of the signal pattern of the TMT, resulting in a temporary interruption of the Link signal.

Page 78
An interruption lasting greater than 15 seconds will cause the Tank Pressure value to flash, the Audible Alarm to sound, and message TMTx>LINK>LOST to scroll. The link will be restored 4 seconds after the VT3 is moved back to its correct position.

An interruption of the TMT Link may also occur while the VT3 is in an area within 3 to 4 feet (1 meter) of a running Dive Propulsion Vehicle. The link will be restored within 4 seconds after the Vehicle is shut off or the VT3 is moved out of that area. When using a Strobe, a temporary interruption may occur shortly after the Strobe flashes. The link will be restored within 4 seconds."
information in quoted text is from Oceanic's VT3 Operating Manual, Doc. No. 12-2705 ©2002 Design, 2006 San Leandro, Ca USA 94577

Now since the wrist unit is not a dumb terminal (dumb terminal meaning it is used for display of information only) but an actual dive computer capable of working independent of the transmitter, then it would mean that the interruption of the signal between the units would be affecting the ability to display the current air supply and time remaining for that air supply. When the link is reestablished, the wrist unit will update the PSI or BAR accordingly. Interruption of the signal does not affect the computers calculations of nitrogen absorbtion and release.
 
visibilityunlimited:
Hi,
Oceanic addresses this in the owner's manual for the VT3 which can be found on their website in PDF format.

VT3 Operating Manual - 12-2705-r01.pdf

The information is on page 77 and 78. If you can't open PDF files, this is what it says

Page 77

"Link Interruption Underwater

During a dive, you may at times move the VT3 out of the signal pattern of the TMT, resulting in a temporary interruption of the Link signal.

Page 78
An interruption lasting greater than 15 seconds will cause the Tank Pressure value to flash, the Audible Alarm to sound, and message TMTx>LINK>LOST to scroll. The link will be restored 4 seconds after the VT3 is moved back to its correct position.

An interruption of the TMT Link may also occur while the VT3 is in an area within 3 to 4 feet (1 meter) of a running Dive Propulsion Vehicle. The link will be restored within 4 seconds after the Vehicle is shut off or the VT3 is moved out of that area. When using a Strobe, a temporary interruption may occur shortly after the Strobe flashes. The link will be restored within 4 seconds."
information in quoted text is from Oceanic's VT3 Operating Manual, Doc. No. 12-2705 ©2002 Design, 2006 San Leandro, Ca USA 94577

Now since the wrist unit is not a dumb terminal (dumb terminal meaning it is used for display of information only) but an actual dive computer capable of working independent of the transmitter, then it would mean that the interruption of the signal between the units would be affecting the ability to display the current air supply and time remaining for that air supply. When the link is reestablished, the wrist unit will update the PSI or BAR accordingly. Interruption of the signal does not affect the computers calculations of nitrogen absorbtion and release.
Click to expand...

thanks for the manual excerpts for clarification. It seems that the link will be re-established in plenty of time prior to the alarms clanging :). A temporary non-indication of pressure and air time remaining is ok..however.

The second part of my question relates directly to the VT3 NOT being a dumb terminal and concerns the structure and robustness of the air time remaining algorithm.
I ASSUME(yikes) that the algorithm inputs are depth, dive time and some calculated rolling average of a number of successive pressure readings and so I am concerned that the link interruption will reset, modify or invalidate the indicated air time remaining.. any clue?

..i am sure i could have asked that in a simpler manner..lol
 
The link interruption will not be long enough to completely mess up the algorithm it uses to calculate those figures. If I understand the computer properly, it will have enough data stored to allow for such interruption and resume the calculations once the link is re-established.

Furthermore, the NDL is what will determine the dive time above the arbitrary ATR which is very loosely based on the depth vs. gas remaining feature. In short, do not rely on the ATR figures since that will change and is not 100% accurate, rather just an indication.
 
Damn.. i guess then i dont have any reason not to buy it!..

lol, thanks all
 
What frightens me is that I understood almost everything that was being said (without having to go out and get a pocket protector and a sliderule). To think that I originally wanted it because of the larger numbers and because it is a sharp looking unit. I am glad to find out that I am not as "technical jargon" challenged as I thought I was.
 
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