The following screen shots illustrate the new Digital Cable Tuner Diagnostic Tool from the Media Center Integrator Alliance (MCIA). I am posting them ahead of the Installment 00B Podcast so you can reference them as we discuss the screens, see what information the tool exposes, and how you can use that information for testing CableCARD-based installations – and troubleshooting issues should they arise. It is important to note that this tool only is available to members of the MCIA. However, using this tool for our examples illustrates how the terminology, architecture, and lower-level information we discussed in the last four Podcasts comes together through a unified User Interface (UI). As we discuss in the Podcast itself, this tool is a great asset for any Windows Media Center integrator. However, it does assume you understand what you are looking at and how all of the pieces fit together. After listening to the previous Podcasts, you now should be more prepared to tackle Digital Cable Tuners and the associated CableCARD infrastructure. Using a tool like this just helps bring it all together.
The DCT Diag tool has the capability to
• Detect the Digital Cable Tuner(s) and display diagnostic and troubleshooting information
• Scan the individual channels and display information specific to each one
• Export the data so that it can be sent to an off-site expert for further evaluation and for archiving the “as built” configuration
The user interface groups the information into several sections.
The tool supports multiple DCTs and lets you expand or collapse the information for each tuner. The following shows two tuner windows, but you can have as many windows expanded as there are tuners in the PC. However, you start to limit the amount of information for each one without scrolling because of the screen size. They are scalable by grabbing the dividers and dragging them up or down.
There is an overall status area in the top left that provides a quick go/no go indication of the state of the DCT and CableCARD. If all three lights are green, there is a good chance everything is paired correctly and you are good to go. Be sure to check the status for each one of the tuners though.
Notice the links on the shot above. The one for the Diagnostic Pages takes you to the URL of the Man-Machine Interface (MMI) Device screen we discussed in the previous two Installments. Shown here is the Card screen showing the links to the details for the CableCARD.
The Traces link shown above takes you to a screen within the MMI that I did not discuss previously. It is a low-level debugging screen showing you the communications occurring within the DCT. Normally, the URL for the MMI screens starts with the <IP address of the DCT>/index.html. Notice that this screen uses /advindex.html (for the advanced views). When you use this address, the extra Traces tab shows up on the navigation bar. The information listed here is not documented and is pretty cryptic, which is why I did not talk about it earlier. However, since the link is available from within the tool, I thought it was worth mentioning.
You can expand the Tuner Details window on the left side of the screen. Notice that it exposes much of the information and “data fields” we have been discussing in the previous Installments. There is a mix of information about the DCT, the current channel tuned to on that tuner, and the CableCARD itself. Note things like the Host Serial Number (used to correlate the tuner information pane to a physical DCT), the Host ID, which we mentioned in detail previously as a potential indicator of not being paired properly or a bad DCT itself, and the Host Firmware version number. One important data point is the Signal Channel value. This is the easiest way to determine to which channel a particular tuner is tuned. As mentioned, one of the great features of this tool is that it displays all of the data normally hidden several screens deep through the MMI screens in a nice unified UI. If you are having problems with a particular channel, this is an easy way to determine which tuner is being viewed at the time. Also notice the OOB lock information and the Code Version Table (CVT) information we mentioned previously. Remember, most of this information is available by navigating around within the DCT’s MMI screens. The tool just takes that same data and exposes it through this graphical UI, which saves a lot of time and effort when testing and troubleshooting the system.
The following screen shows the main channel lineup window. We discuss this in greater detail in the Podcast, so I will not try to explain it all here. Essentially, this is the Virtual Channel Table (VCT) information with the Service ID channel numbers matched up to the names of the channels that are found in the downloaded Windows Media Center Electronic Program Guide (EPG). It also shows which channels are being tuned by which one of the Forward Application Transport (FAT) tuners, which indicates if it is analog (NTSC) or digital (QAM-256 in this example).
This screen also provides an instant visual indicator that the Signal Level may fall outside of the recommended range for certain channels. As we have mentioned several times, the exact Signal Level numbers passed back from the ATI DCT may not be accurate. However, an acceptable range has been determined through extensive testing. If the level is marginal, a channel will have a yellow indicator. If it falls outside of that range and is either too low or too high, it will be in red. It always is good to investigate these further because they may be indicative of some lower-level problem. Right now, there is no way to sort by frequency, but if a group of channels are failing and they fall within a frequency range window, that usually indicates a problem with the RF cabling plant itself and the Signal Level should be tested again across the full spectrum.
There is a Channel Details window that opens whenever you click on one of the channels in the list. By using the Update Channel button, it re-tunes that channel and re-reads the information from that Transport Stream, which then is updated in the channel list and in the details window.
The following screen shot shows the details for a ShowTime HD channel. This important thing to observe is that the Authorization field indicates that the customer is subscribed to this channel. You should match all of the channels to which your client is subscribed with the list you printed out before going on site to ensure that the system shows all appropriate channels actually are Subscribed. Also note the Copy Control Information (CCI) bits we discussed previously at the bottom of the Details pane. In this case, it is hex 02, which means you only can copy the show once (refer to the blog post for Installment 008 for the values).
This view illustrates the transition point from analog to digital channels. This usually happens somewhere around channel 100, but this is not always the case. You can see that most of the channels below 99 are analog (NTSC) and those above 101 are digital (QAM). Notice that several of the channels do not have names associated with them. That means there is no entry for that particular channel’s Service ID in the EPG. Also notice that channels 95 and 96 have a Transport Stream detected, but there is no associated entry in the EPG because there is no Name. As an integrator, you need to investigate these channels to determine if they should be viewable or if you need to consider disabling them via the TV Setup Channel Lineup wizard within Windows Media Center.
This shot shows that not all analog channels are down in the lower numbers. Once again, there does not appear to be an entry in the EPG for either one of these, so you want to tune them in just to check them out and see what is being broadcast.
The last “valid” channel for this cable provider is channel 1370. The DCT Diag Tool itself scans up to channel 1400, although you can increase that value by modifying the TunerScanWPFClient.exe.config file in the tool’s file folder (C:\Program Files\Media Center\Digital Cable Tuner Diagnostics) should that become necessary.
This following example is discussed in more detail in the Podcast, but I will summarize it here. When you perform the initial channel scan, the application tunes to each channel sequentially, pulls in the Transport Stream information, and then goes to the next channel. As it is, it already takes a while to scan all 1,400 channels, especially when there are multiple tuners. This initial scanning process only polls each channel once. Sometimes the data the scanning process obtains is not quite accurate for whatever reason. Notice that the OXYGEN channel is showing red, which usually indicates the Signal Level it read during the initial scan is outside of the acceptable range we mentioned before. The easiest way to test this channel is to click the Update Channel button at the top of the Details pane to re-tune to that channel and to read in the information from the Transport Stream again. It is a good idea to do this several times to ensure you are getting consistent data.
Notice that, after updating the channel information, the OXYGEN channel no longer fails the Signal Level test. If it stays red, chances are you are not going to be able to tune to that channel properly. If that is the case, it is a good idea to check the RF cabling plant at that frequency with a good Signal Level meter to try to determine the cause of the problem. Remember that it not always points to the Signal Level’s being too low. It also could be too hot. Another troubleshooting technique is to connect the cable directly to a TV with a digital cable tuner to see if it can be viewed on a regular TV.
Notice the group of channels below that have an Authorization value of NotSubscribed. Although these channels also do not show up in the EPG (no Name), you should double check your channel lineup and your client’s subscription pack to make sure that they are not supposed to be available. They all have the same frequency listed for each channel in this capture, so they probably are not anything to worry about, but it is just another observation that you may want to investigate as part of your final system check.
We all know that Windows Media Center does not have a Reverse Data Channel (RDC) available, so you cannot request Pay Per View (PPV) events. It appears that there are some ESPN PPV channels listed in the EPG since channels 521-526 have Names. You may need to go into the TV Setup Channel Lineup wizard in Windows Media Center and disable these channels so they do not show up as being available. Tweaking the fine points of the system like this is what distinguishes a good integrator from your run-of-the-mill installers, which is why your clients are paying you to configure their systems for them.
It appears there also is an associated Pay Per View Preview channel listed in the EPG. Once again, you should disable this channel so it does not show up as one of the available channels within the Windows Media Center experience.
The following group of channels indicates that there are entries for them in the VCT and EPG, but there are no Transport Streams, which means they will be blank if you tune to them. You can tell this because they are grayed out and there are no values in the columns. By the looks of the Names, it appears they are valid channel names and that they should be available. As it turns out, this cable provider recently started rolling out Switched Digital Video (SDV). I will not go into the details of SDV here, but essentially it is a way for the MSO to save bandwidth by not broadcasting less-viewed channels constantly. If someone wants to view one of those channels, the request normally is sent back to the headend and the channel then is broadcast to a neighborhood. After the show has been viewed, that bandwidth becomes dormant again. As we all know though, Windows Media Center does not support a Reverse Data Channel (RDC) that can send the request to view upstream to the headend. Therefore, these channels will not be viewable (unless a neighbor happens to request one of them at the same time someone using WMC wants to view it). You pretty much have two options.
1) Disable these channels inside of Windows Media Center so that they do not show up in the EPG.
2) Explain SDV to your client and let them know that viewing these will be intermittent at best. I prefer number 1, but that is up to you.
I mentioned that the MSO had started implementing SDV for that area (without alerting anyone, of course). It took us a while to track down someone who could tell us that, but they were kind enough to send us a spread sheet with the current list of channels that were affected. As you can see below, this channel group matches up directly with a group in the list they sent. Without having the MCIA DCT Diag Tool, it really would have been tough to track down this problem and to speak intelligently to the provider about the problem we were experiencing. The UI was able to draw our attention to the cause and saved us hours of troubleshooting time.
•Flix 275
•Encore Action 276
•Encore Love Stories 277
•Encore Mystery 278
•Encore Drama 279
•Encore Westerns 280
•Encore 281
•Encore WAM West 282
•Encore West 284
•Encore WAM 285
•Independent Film Channel 286
Here is another group of grayed out SDV channels that also matched up with a group in the list the MSO sent us. The Names on these channels indicate (at least to me) that they probably are not worth worrying about, so we disabled this group without even checking with the client.
Hopefully these screen shots have shed some light on the MCIA DCT Diag Tool, how it can be used, and why it might be worth joining the MCIA just to be able to get it. It pays for itself the first time you save a day’s worth of troubleshooting aggravation. Please listen to the associated Installment 00B of The Custom Integrator Show for more details and our wrap-up of Digital Cable Tuners and CableCARDs.
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