How to change channels between tuners?

[omelveny]

I press the down arrow on the remote to get to the other tuner, but how do I change the channel on that tuner? When I do switch tuners, I change the channel, but when I go back and forth it still has the same channel as before. Really dumb question (if you understand it...), but any help is appreciated

[ShiningBengal]

I press the down arrow on the remote to get to the other tuner, but how do I change the channel on that tuner? When I do switch tuners, I change the channel, but when I go back and forth it still has the same channel as before. Really dumb question (if you understand it...), but any help is appreciated

You change the channel of the tuner you are using either by entering the new channel number, or by going to the guide and picking which channel you want to navigate to. When you do a down arrow, the channel you left when you switched tuners will still be on the channel you left it at...unless, of course, it needs to change channels to record something. In that case, it will be on the channel it is recording.

[TonyD79]

Normal behavior:

Tuner A is on Channel 628
Tuner B is on Channel 501

You are watching Tuner A. Push down arrow to watch Tuner B. Tuners stay on channels.

If while watching Tuner A, you go to Channel 206, then Tuner A is on 206 and B stays on 501.

If while watching Tuner B, you go to Channel 520, then Tuner A stays on what it was on and Tuner B goes to 520.

Now, this is where it can get tricky.

Back to:
Tuner A is on Channel 628
Tuner B is on Channel 501

If you are watching Tuner A, then use the down arrow to get to Tuner B, then key in 628, the system knows that you already have 628 in buffer and instead of changing channels, it switches buffers for you. So you switch from Tuner B to Tuner A and Tuner B remains on 501.

The same will happen if A is on 4 and B is on 5 and you push the channel up button while watching tuner A.

[Mark Lopez]

Normal behavior:

Tuner A is on Channel 628
Tuner B is on Channel 501

You are watching Tuner A. Push down arrow to watch Tuner B. Tuners stay on channels.

If while watching Tuner A, you go to Channel 206, then Tuner A is on 206 and B stays on 501.

If while watching Tuner B, you go to Channel 520, then Tuner A stays on what it was on and Tuner B goes to 520.


I know that is how it is 'supposed' to work, but almost always I have it do this.

Tuner A on 628
Tuner B on 501

I want to change tuner A to 204, but even if I'm on Tuner A and it's not recording, it will change tuner B to 204 instead and then switch tuners. Tuner A remains on 628. Sometimes the only way I can get tuner A to switch channels is to force tuner B into record mode and then change the channel on tuner A.

[TonyD79]

I know that is how it is 'supposed' to work, but almost always I have it do this.

Tuner A on 628
Tuner B on 501

I want to change tuner A to 204, but even if I'm on Tuner A and it's not recording, it will change tuner B to 204 instead and then switch tuners. Tuner A remains on 628. Sometimes the only way I can get tuner A to switch channels is to force tuner B into record mode and then change the channel on tuner A.

I have never seen this on three dirfferent DirecTiVos.

[TyroneShoes]

I know that is how it is 'supposed' to work, but almost always I have it do this.

Tuner A on 628
Tuner B on 501

I want to change tuner A to 204, but even if I'm on Tuner A and it's not recording, it will change tuner B to 204 instead and then switch tuners. Tuner A remains on 628. Sometimes the only way I can get tuner A to switch channels is to force tuner B into record mode and then change the channel on tuner A.
I think you are at leat half right, Mark. This IS the way it works, but it also is SUPPOSED to be the way it works. Others have not "seen" this because although this is exactly what happens, it appears to work the way earlier theorized. But it really doesn't.

The 2-tuner system actually has no way for the customer to directly change what channel is routed into a particular tuner as a UI function, although quite often that can appear to be the resulting effect. For live TV the UI is involved directly with the screen OUTPUT only, and not directly with the channel choice on the tuner INPUT. Changing the tuner channel INPUT (for live TV) is a side-effect of changing the displayed channel OUTPUT, only, and when and if that happens for a particular UI event will depend only on the record state of either tuner as well as which tuner OUTPUT is currently displayed, and sometimes may NOT depend on what channel the user actually selects. The UI is designed to change the channel display OUTPUT seamlessly for the customer by making choices automatically about which tuner INPUT to change depending upon current status, meaning what it actually does can change if the conditions change.

So, when you set out to change the tuner INPUT channel, you have to approach it from the standpoint of knowing how to set the displayed channel OUTPUT, and use that info to spoof the system into doing what you want it to, since it is not designed to change the tuner INPUT channel directly, only as a side-effect of changing the displayed channel OUTPUT. And that is the method you described, which works well, even though it is technically a work-around.

The 2-tuner system typically chooses the tuner OUTPUT NOT displayed to change the INPUT channel on, because that is the best way to preserve the buffer on the tuner connected to the channel OUTPUT that is currently displayed, which it rightfully assumes is usually the buffer most worth saving. And it is smart enough to know it doesn't have to change the INPUT channel on either tuner if the OUTPUT NOT displayed already has that channel connected to it. In that case, instead of changing the INPUT channel, it simply changes which OUTPUT is displayed.

Folks get confused by this because there is no input/output dedication between what the tuner INPUT is, and the displayed OUTPUT. Folks incorrectly assume that a "tuner" refers to an input/output pair, but it does not. The STB has a router built in that routes channels into each tuner, and can also route the output of either tuner into the display. Which tuner you see depends on the current status of that router. When you change channels it can decide to do different things for the exact same command, depending upon the current state.

So under certain circumstances it can appear that you have changed channels and are still looking at the same tuner, when actually the other tuner's output has been rerouted into the display. Also, the two "red" buttons on the screen are not dedicated to particular tuners, and can flip-flop under certain circumstances. This can lead to assumptions about which tuner is visible that are not really true, and which the UI assumes are unimportant anyway. Under certain conditions from the standpoint of the UI it makes more sense to do an invisible flip-flop in the background than to present the user with outputs that seem to have "swapped tuners", even though that behavior can run counter to setting up dual buffers for a viewer "swap" session.

From the point of view of the UI, there is no permanent indication of "this is tuner A" and "this is tuner B", meaning there is no firm indication to the user which tuner is which, or which is displayed, or which has a particular channel routed into it. You can determine this for the current state by changing the output back and forth, but it will swap on its own under the right circumstances. From the point of view of the UI, there is only the concept of "tuner curently displayed" and "tuner currently not displayed", and the status concept of "recording as a clip" and "recording only to the buffer", which is what the red dots imply. But those red dots are not permanently representative of actual tuners, and can swap positions on their own under the right circumstances.

This behavior is perfectly in line with the Tivo concept, which is to only allow the user to see what they need to see, and to automatically perform any dirty-work needed to get there seamlessly, transparently, and most importantly, invisibly, in the background, to make the Tivo experience easy and flexible from the point of view of the user. This can ironically make the system more difficult to understand if you want to get under the hood and do something like set up a 2-tuner buffer viewing session.