# USB connection w/ Tuning Adapter necessary?



## allstarz (Nov 21, 2014)

Why does the USB connection need to be made between the tuning adapter and the Roamio when there is a coax connection between the two? What would happen if the USB connection was not made?


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## rv65 (Aug 30, 2008)

You need USB as that is how the Tivo communicates with the tuning adapter. If you just use coax then the tuning adapter would have nothing to communicate with.


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## socrplyr (Jul 19, 2006)

The coax connection to the tuning adapter is for it to talk to the cable company. The coax connection to the Tivo is for the Tivo to get content (channels). The USB connection is for the Tivo to tell the Tuning Adapter what channel to request and the Tuning Adapter to tell the Tivo where to tune it. Without it, you effectively don't have a Tuning Adapter.


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## tarheelblue32 (Jan 13, 2014)

All communication between the tuning adapter and the TiVo takes place over the USB connection. There is no communication between the TiVo and the tuning adapter over the coax, which is why you don't even have to use the RF output on the tuning adapter. In fact, most people suggest you use a splitter so you don't have to use the RF output of the tuning adapter, as it can cause problems if you are using MoCA. If you disconnect the USB cable between the tuning adapter and the TiVo, the TiVo will just revert back to using the CableCard only. Many of your channels will probably still work just fine with the CableCard only, but you won't have access to any SDV channels.


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## pppingme (Apr 21, 2012)

To simplify, TiVo doesn't have any way to send a signal over the coax, think of the TA as a cable modem (and it really is about that). The USB tells the TA what channel is needed, the TA sends that back to the cable company, the cable company responds to the TA with the channel mapping, and the TA responds to the tivo through the USB.

This is also why the TA doesn't need to be "inline" in the coax path between the cable company and the wall, its only purpose is to send signals to the cable company.

Comcast doesn't use a TA because they are smart enough to accept that instruction over IP (over the internet), thus eliminating the bulky extra hardware.


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## tarheelblue32 (Jan 13, 2014)

pppingme said:


> Comcast doesn't use a TA because they are smart enough to accept that instruction over IP (over the internet), thus eliminating the bulky extra hardware.


I'm not sure exactly what you mean by this, but the reason you don't need a tuning adapter with Comcast is because none of their channels are SDV. You also don't really need to use the tuning adapter on any cable system if none of the channels you care about watching are SDV channels.


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## allstarz (Nov 21, 2014)

Thanks for the great answers. Since I am on a Charter system, I believe some or all of my channels are sdv. So, why would I continue to receive all the channel with the USB cable disconnected? With the USB cable disconnected the are no changes that I can tell. Now,why I have the USB disconnected is another issue, in short, the 20.4.5c software rolled out recently, has newer security certificates that do not pair with the T.A. Firmware. I constantly get a blue message screen, that tells me to remove the USB connection for the message to go away. Until this pairing issue is resolved I must have the USB disconnected. Hence, my questions. So, how long will I continue to receive channels with the USB disconnected?


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## tarheelblue32 (Jan 13, 2014)

allstarz said:


> Thanks for the great answers. Since I am on a Charter system, I believe some or all of my channels are sdv. So, why would I continue to receive all the channel with the USB cable disconnected? With the USB cable disconnected the are no changes that I can tell.


Any channels you can receive with the USB cable disconnected are not SDV channels. Cable companies that use SDV still have the most watched channels as traditional non-SDV channels. Look around your channel lineup at channels you never watch, like local public access channels or foreign language channels. I bet you'll find that some of those are unavailable without the tuning adapter.



allstarz said:


> Now,why I have the USB disconnected is another issue, in short, the 20.4.5c software rolled out recently, has newer security certificates that do not pair with the T.A. Firmware. I constantly get a blue message screen, that tells me to remove the USB connection for the message to go away. Until this pairing issue is resolved I must have the USB disconnected. Hence, my questions. So, how long will I continue to receive channels with the USB disconnected?


Forever, because those aren't SDV channels you are watching if you have the USB cable disconnected. As soon as you disconnect the USB cable to the tuning adapter, the CableCard takes over completely and all channels you can see are non-SDV. As I said above, if none of the channels you care about watching are on SDV, then you really don't need the tuning adapter at all.


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## pppingme (Apr 21, 2012)

tarheelblue32 said:


> I'm not sure exactly what you mean by this, but the reason you don't need a tuning adapter with Comcast is because none of their channels are SDV. You also don't really need to use the tuning adapter on any cable system if none of the channels you care about watching are SDV channels.


Comcast does have SDV in some markets, not all. I don't know which. But, the real point comes down to the tivo acheives 2-way communication via IP.


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## tarheelblue32 (Jan 13, 2014)

pppingme said:


> Comcast does have SDV in some markets, not all. I don't know which. But, the real point comes down to the tivo acheives 2-way communication via IP.


Tuning adapters do facilitate 2-way communication, but I don't think they use IP. And if Comcast does have some SDV markets, you would still need a tuning adapter in those markets to receive any SDV channels.


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## pppingme (Apr 21, 2012)

tarheelblue32 said:


> Tuning adapters do facilitate 2-way communication, but I don't think they use IP. And if Comcast does have some SDV markets, you would still need a tuning adapter in those markets to receive any SDV channels.


Tuning adapters are IP devices, but thats a side point. Comcast establishes 2-way communication via IP, this is why you can do on-demand through the tivo. The tivo uses IP as the way back to comcast. This is also why a TA isn't needed for comcast. Even TWC has admitted this is easy and doable, but they claim setting up a proxy server (which is already there anyway to communicate with the TA's) is more expensive than dealing with all the TA's.


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## XIBM (Mar 9, 2013)

allstarz said:


> Thanks for the great answers. Since I am on a Charter system, I believe some or all of my channels are sdv. So, how long will I continue to receive channels with the USB disconnected?


When Charter goes all digital they get enough bandwidth back to eliminate SVD. I have been told they are planning to eliminate SVD system wide to eliminate the extra additional switching hardware and time lag. By unplugging my TA when they went all digital my PXL4 seems to switch all channels a bit faster but I did loose one channel which I think is an authorization problem on my CC that the TA and charter digital box allows.


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## HarperVision (May 14, 2007)

pppingme said:


> Tuning adapters are IP devices, but thats a side point. Comcast establishes 2-way communication via IP, this is why you can do on-demand through the tivo. The tivo uses IP as the way back to comcast. This is also why a TA isn't needed for comcast. Even TWC has admitted this is easy and doable, but they claim setting up a proxy server (which is already there anyway to communicate with the TA's) is more expensive than dealing with all the TA's.


True it's IP through the coax QAMs, but that's for TAs where needed like on TWC and some Comcast markets.

Comcast uses IP for On Demand, yes, but they DO NOT use IP (via Ethernet) for SDV......yet. An IP TA software seems to be in the works though. Hopefully soon.


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## tim1724 (Jul 3, 2007)

XIBM said:


> When Charter goes all digital they get enough bandwidth back to eliminate SVD. I have been told they are planning to eliminate SVD system wide to eliminate the extra additional switching hardware and time lag. By unplugging my TA when they went all digital my PXL4 seems to switch all channels a bit faster but I did loose one channel which I think is an authorization problem on my CC that the TA and charter digital box allows.


Not necessarily. In many markets they're keeping SDV and using the freed-up bandwidth to add channels and/or increase internet bandwidth. My local Charter franchise went digital-only about a year ago and still uses SDV heavily. (I got to reboot my tuning adapter just last night. yay. And twice in the past three months I've had to get them to reauthorize the stupid thing.)


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## tarheelblue32 (Jan 13, 2014)

tim1724 said:


> Not necessarily. In many markets they're keeping SDV and using the freed-up bandwidth to add channels and/or increase internet bandwidth. My local Charter franchise went digital-only about a year ago and still uses SDV heavily. (I got to reboot my tuning adapter just last night. yay. And twice in the past three months I've had to get them to reauthorize the stupid thing.)


SDV is like crack to cable companies. Once they start using it, it's really hard for them to give it up.


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## CharlesH (Aug 29, 2002)

Just for clarification, IP does not equal Internet. The TAs use Internet Protocol (IP) over the cable, but this has nothing to do with the Internet; the cable is used to transmit the IP packets to the SDV servers. Comcast VoD can either use IP over cable (for its own set top boxes), or IP over the Internet (for TiVo boxes). "All they had to do" is allow the VoD servers to talk to the device over the Internet and not just over the cable. In fact, you don't even need Comcast Internet service for Comcast VoD to work (but you DO need Comcast TV service); any Internet connection will work. And as mentioned, work is being done to get SDV working over the Internet and eliminating the need for special Tuning Adapter hardware, but that is a work in progress.


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## pppingme (Apr 21, 2012)

CharlesH said:


> Just for clarification, IP does not equal Internet.


True, but once something is IP enabled, getting it to work over the internet is a no brainer.


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## Bigg (Oct 31, 2003)

tarheelblue32 said:


> SDV is like crack to cable companies. Once they start using it, it's really hard for them to give it up.


LOL. I could see how that would happen.

Charter could be using SDV only for channels in higher-up packages that are more expensive than what the OP has. Verizon is doing something similar right now with MPEG-4, although the implications are different, since any Premiere or Roamio can handle MPEG-4 without additional hardware.


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