VT3 Transmitter Link up at gas switching...

[egdiver]

As a new VT3 owner (4 dives on the unit ) I get a lost link message when switching from gas 1 to gas 2 and 3.
Let me expand on the senario...
Multiple single tank dives with gas mixes ranging from 21% to 36% O2, same regulator and transmitter on all dives.
VT3 set up: Gas1 @ 21%, Gas2 @ 32%, Gas3 @ 36%, TMT1 set ON, addressed to 069 127 and works fine, TMT 2-3 set for SELF and ON, Both TMT2 and 3 addressed to 069 127 same as TMT1.
After the switch is complete the error message LOST LINK is displayed. The link should take place in 5 - 15 seconds, but no link is made.
In therory I would believe that if the VT3 were addressed on all three TMT Screens to recieve 069 127 then a single transmitter could be used at different FO2 levels...

 

[Fordan]

Wouldn't it be simpler just to go into the Set FO2 for Gas 1 and change it between dives to whichever EANx you're using? I believe that's the intended way to change your Nitrox mix...

Your way is interesting, but you'll run into other issues even if you straighten out your transmitter issues. Some features of the VT3 expect that Gas 1 is your primary tank, so they don't work on Gas 2 & 3, like the Turn Pressure alarm & Plan mode.

 

[egdiver]

The VT3 is proggramed to prevent the f02 for gas 2 and 3 being set at values lower than the f02 set point for gas 1, ( Oceanic says safety ) that being said, if you set gas 1 at 36% and a dive is made, there is no going back to < 36% f02 set point for gas1 ) in that activation period... also, the planning mode uses the set point for gas 1 so 36% would be the minimum f02 for planning all rep dives !
The only way to accomplish multi gas settings is to work around a rather strange program which is setting gas 3 at the higest f02 and working backwards i.e. gas 1 at 21%, gas 2 at >, and gas 3 at >
Actully this is not the issue,
The issue is linking a single transmitter to all 3 gasses in the VT3,
I think the boys at Oceanic have a R&D project...

 

[ianr33]

The above posts make me really appreciate my bottom timer

 

[Fordan]

The VT3 is proggramed to prevent the f02 for gas 2 and 3 being set at values lower than the f02 set point for gas 1, ( Oceanic says safety ) that being said, if you set gas 1 at 36% and a dive is made, there is no going back to < 36% f02 set point for gas1 ) in that activation period... also, the planning mode uses the set point for gas 1 so 36% would be the minimum f02 for planning all rep dives !

I don't have my VT3 yet; it's supposed to be arriving in the shop in the next week or so, so all I say is going from the manual. I apologize if I seem dense...

Is this true even if you have the FO2 50% DEFAULT option turned on? The manual says that that resets the FO2 for Gas 1 to be 50% (for O2 calcs, 21% for N2 calcs), unless you set the FO2 for Gas 1 before the next dive, which would seem to imply you can go backwards, unless it locks in the value at the time of the dive.

And an activation period would be from your 1st dive until 24 hours after your last dive? Even if they were trying to enforce the deepest dive first guideline, locking the FO2 to only go up wouldn't allow you to change your mix for a dive the next morning to allow you past your previous day's shallowest dive mix's MOD. And even given only a single day of diving and trying to force the deepest dive first rule, I could dive to 80' on EAN36 followed by 60' on EAN32 safely.

If this is the case, I really don't understand the rationale behind it.

 

[egdiver]

I have the 50% default feature disabled, but the fact still remains if you program gas1 with an FO2 value and dive is made, you can not program an FO2 value for gas1, 2 or 3 that is less than the value of the previous dive... Also this effects the planning mode in the same manner since the planning mode uses the value that has been set for gas1.

When you have your VT3 and apply it to your needs, you may understand better the reasons for these workarounds...

I have been in contact with tech support regarding transmitter linking issues and they did mention the the set point problem. Lets hope they come up with a solution, after they are done with inventory !

 

[egdiver]

The above posts make me really appreciate my bottom timer

Gee... now thats helpful !
Have another Corona.

 

[cummings66]

I could be wrong but I'd swear I've dove 32% and then 21% in the same day. I'll have to check my logs on that but I think I've done it with no issues from my VT3.

 

[ianr33]

Gee... now thats helpful !
Have another Corona.

Glad to be of service

Tonight is a Lagavulin evening though.

I dont understand why anybody would need/mess with a wireless air integrated computer instead of an spg. Seems to be lots of downside and no benefit.But thats just me.

I will leave your thread in peace now.

 

[Fordan]

I dont understand why anybody would need/mess with a wireless air integrated computer instead of an spg. Seems to be lots of downside and no benefit.But thats just me.

"Instead" is an assumption. When mine arrives, I expect to dive with a small console SPG/depth gauge/compass as a backup, but don't expect to unclip it much except to use the compass.

As to why, I like the idea of having everything on my wrist to see with a single glance.