Can I ask a Stupid Question?

[pk6301]

I have been on CPAP for the last 3 years. I have adjusted well and am feeling alot better than before, that is not the problem.
In monitoring my data it cam to mind the other day " How the heck does the machine know what day and time it is, what time i put on my mask, what time i have an episode, what time I wake, ect..ect.. I received a new machine about a month ago from the VA, if I were to plug in my old back-up machine it would still know the date and time, if not the date at least the time. I do not think there is a battery in the machine, and I do not see a time set-up menu, so how is this possible?
I know it is a silly question, but I just had to ask.

[PaulaO2]

It's not a stupid question.

The machines have a type of memory that stays there even after the power is out. So, yes, it would know the time and date. They do not, however, adjust for the time changes.

[shanzlik]

Many electronic devices that store the date and time use a small battery on the motherboard to keep it going when the power is off or the machine is unplugged. Computers typically have these, and I wouldn't be surprised if the CPAP has one.

[zonk]

The only stupid question is the one haven,t been asked
The S9 have a clock so you can set/change the time manually but understood from greatunclebill that PR System doesn't have a clock that can be seen or a way to change it.

[JumpStart]

I have been on CPAP for the last 3 years. I have adjusted well and am feeling alot better than before, that is not the problem.
In monitoring my data it cam to mind the other day " How the heck does the machine know what day and time it is, what time i put on my mask, what time i have an episode, what time I wake, ect..ect.. I received a new machine about a month ago from the VA, if I were to plug in my old back-up machine it would still know the date and time, if not the date at least the time. I do not think there is a battery in the machine, and I do not see a time set-up menu, so how is this possible?
I know it is a silly question, but I just had to ask.

First, welcome to the forum. Now, to your question.

Hmmmm... Well, if there isn't a well hidden battery, like one of those flat round things (model 2032, perhaps), maybe earlier cpap models came with "time creatures", sort of like leprechauns. One of our posters lives somewhere close to the original location for leprechauns, so he might chime in if he feels they might be involved. :grin:

Seriously, I am as puzzled by the time/date as you are. If it connected to something more than an electrical plug, I might have a guess other than a battery. As to the other determinations, those are the result of the sensors built into the machine - volume of flow sensor (in and out, and the interruptions of each), pressure sensor, and the timing of how the two interact determines events. But to record these requires electricity in one form or another. If you have/had a data card, it would be written to that, otherwise probably to an internal read-only memory chip. Each would record for their originally determined limits, and every time you again plugged in the machine, would regurgitate that information.

Again, welcome, and I hope you visit frequently. Let us know if you find the source of the time/date.

[Sleepster]

The only stupid question is the one haven,t been asked
The S9 have a clock so you can set/change the time manually but understood from greatunclebill that PR System doesn't have a clock that can be seen or a way to change it.

Yes, I think that's right. That's why, when setting up a new profile in SleepyHead, you have to enter your time zone. I've never used Encore, but I imagine it must work the same way.

I've heard that there's a propritary cable that you can plug in to the bottom of a PRS1 to set the time and update the firmware, but it's not available to end users.

[greatunclebill]

The only stupid question is the one haven,t been asked
The S9 have a clock so you can set/change the time manually but understood from greatunclebill that PR System doesn't have a clock that can be seen or a way to change it.

Yes, I think that's right. That's why, when setting up a new profile in SleepyHead, you have to enter your time zone. I've never used Encore, but I imagine it must work the same way.

I've heard that there's a propritary cable that you can plug in to the bottom of a PRS1 to set the time and update the firmware, but it's not available to end users.

setting the clock in the factory to my time would do no good if i moved with my cpap to a new time zone. plus do not know where each machine is going.

the rp time is set to gmt. when you go into sleepyhead or encore, they use your computer clock to add or subtract from gmt to get the time. that's what i've heard. it can be proven or disproved by changing your computer clock before you use sleepyhead. i did the balloon, somebody else do this one.

[Sleepster]

the rp time is set to gmt. when you go into sleepyhead or encore, they use your computer clock to add or subtract from gmt to get the time. that's what i've heard. it can be proven or disproved by changing your computer clock before you use sleepyhead. i did the balloon, somebody else do this one.

Well, I'm not going to do it, Bill. But I think that you'd have to change your time zone in your SleepyHead profile to make the time change in SleepyHead.

[pk6301]

I see it is not a stupid question after all, I also see that we are getting a variety of answers..This is interesting..We will have to go to the manufacturers to get the straight answer i guess..If I find out I will let you know.

[PaulaO2]

For it to retain the memory, it is one of two things:

A battery (which will eventually fail)
An itty bitty hard drive called a Flash Drive which retains memory even if unpowered (like a USB memory stick)

Did you ever plug your old machine in to see if it retained the date and/or time?

Do you feel intrigued enough to take it apart and see it's innards? (if you do take it apart, take photos and share!)