They've got the problem where they conflict with each other when multiples are in use. Scubapro supports 8 with no special anything. Ratio supports 10 at a time. In both cases there's no special green or yellow or whatever. You just use up to 8 or 10 of the appropriate brand transmitter. A tech diver could concievably use one of these computers and have pressure data for every single bottle he brought for the dive. Not that a tech diver should be using a Scubapro (for other reasons) but as far as transmitters go, Scubapro is good. Ratio is a solid tech computer, although there are things I dislike about it.
The fact that the PPS transmitter transmits when pressurized regardless of change in pressure. I.e. when you put your reg on a tank, test everything, and sit down for an hour long boat ride. With other brands you don't have to turn things back off in order to conserve battery.
I think there's something hokey about the pairing system with PPS as well but I can't remember and don't want to look it up at the moment. I'm sure users of PPS transmitters are used to it. With scubapro or ratio, you pair the tx when you buy it. You could also connect them to other computers simultaneously (i.e. for buddy or sidemount doubles). Once and done. Forever. Even if you change batteries on the computer and the transmitter. All you do to pair the transmitter is touch the computer to the transmitter for a few seconds. The computer will pop up with a "do you want to pair to this tx" type screen on its own.
Now, for a long time I did have battery life issues with my scubapro transmitters. That turned out to be a tech at my local shop putting the wrong battery in there. Once I started doing it myself, things went well. Not sure if that's Scubapro's fault with their documentation or the shop guy. I haven't had a low battery warning since I started doing it myself but I still replace the battery every couple years out of an abundance of caution.
I'm not sure when Ratio released their transmitters but the scubapro was released around 2005, so it's not exactly cutting edge newness.
That's why I think PPS Sucks compared to the other options, and why I think it's so great that Shearwater rolled their own.
On paper they have issues with conflicting when multiple are in use. In the real world, it is virtually never a problem. And it it were, it is an easy one to detect before splashing and fix (by turning off one transmitter then turning it back on). An "on paper", not-real-world, problem does not mean the PPS transmitters are awful (to ME, anyway).
With the Shearwater Swift, Shearwater has posted in the manufacturer's forum that it transmits every 5 seconds - until it detects no pressure change for some time. Then it changes to transmitting every 15 seconds. Just like other brands. With the PPS, it is true that it transmits every 5 seconds while it is on. I have no problem with that.
Transmitting every 15 instead of every 5 just reduces battery consumption. It doesn't stop it. None of the schemes anybody uses would have saved the transmitter battery when my CCR's dil valve got rolled on a little bit in transport and then sat for 2 months over Christmas. Even transmitting every 15 seconds, it still would have been dead when I went to use it. I'm not at all worried about the battery used during even a 3 hour boat ride. The difference between amount used every 5 seconds versus 15 seconds is inconsequential (to me) compared to the overall battery life the PPS transmitters get.
The PPS transmitters have an ID. You program it into your computer and it stays there forever. If your computer loses the "pairing", then that is an issue with the computer, not the transmitter. The transmitter's ID never changes. If the computer can only store 2 (or 4 or however many) transmitter IDs, again, that is an issue with the computer, not the PPS transmitter.
The PPS transmitter is stone simple and I like that. It doesn't implement less-than-stone-simple power management and I like that. The battery lasts PLENTY long enough as is and simpler is better when complexity is not necessary.
That's not how transmitters work. Sleep doesn't mean sleep.
All transmitters work in roughly the same way (despite weasel words in the marketing). When the the sensor sees zero pressure, the radio transmitter turns off. When it's off and the sensor sees some pressure, it turns the transmitter on. You know this.
For "Sleep" when the Sensor sees no change of pressure over a time, it'll reduce the frequency the transmitter sends data (or might turn it off)
The computer just displays the last received pressure value from that transmitter changing only when it receives an update or goes into surface mode (however they've programmed the software)
So diving if multiple cylinders and transmitters you always know the current pressure of that cylinder.
See above. The additional complexity of that power management is simply not necessary. And when it's not necessary, simpler is better.
My Eon supports 10, but as you rightly point out during a dive you'll rarely use more than 2 or 3.
I have all the transmitters in my household registered on my computer (7) While the transmitters are generally kept with the gear, having them all registered on the computer just makes life easier if I pick up the "wrong one"
The S/W Fan club always assume that reason for limited transmitters and/or needing different colour transmitters to prevent the chance of interference on teh Shearwater lies with the PBS transmitter.
But transmitters are pretty dumb, and as you highlighted you've never seen and issue on yoru Oceanic, as I haven't in over 1000hrs underwater on my Eon with multiple transmitters
I believe the "issue" lies with how SW have implemented AI on their computers. Upto this latest update they've also only made gas consumption calculations from 1 transmitter rather than both (as every other manufacturer does)
So you could suggest that its the SW computers that are the limiting factor NOT the transmitter
Shearwater haven't done anything different with their AI implementation than any of the numerous other computers that work with PPS transmitters - as far as handling transmitter interference goes. Limitation on # of transmitters programmed into the computer is definitely down to who makes the computer. But, limitations on # you can use at once - due to transmitter interference - is purely the PPS transmitter design.
