who sends date/time?

d4g4m · 8-Nov-2014, 1:18 AM

I recently purchased a Vizio E480i-B2. Signals are received with an attic antenna 40 miles from Riverview FL tower [Tampa broadcast area] Signals are strong with no drop out. Problem is with receiving and keeping the correct date/time. While on any channel, date/time drops off and reverts to January 1, 1970 midnight. If the TV is turned off, then back on, correct date/time is shown. Sometimes when changing channels, if it is the correct date, the time may be off by a few minutes and it takes a second or two for the correct time to fix itself. [Channel #, name, program name and info is always correct]
Is the date/time transmitted separately by each station or is there one entity in a local area that does it?
I'm thinking there is a problem with the TV date/time circuit receiving/keeping the correct date/time. Vizio tech support told me that the TV is a 'smart' TV and I should be getting the correct time from a router/modem. I only bought the TV because it is 48" 1080 120 Hz

timgr · 8-Nov-2014, 1:53 PM

The standard date and time - WWV http://www.nist.gov/pml/div688/grp40/wwv.cfm

There's also WWVH in Hawaii - http://tf.nist.gov/stations/wwvh.htm

There are also internet feeds for standard date and time - http://tf.nist.gov/tf-cgi/servers.cgi

This is likely where your internet-connected devices are getting the data and time. There may be a menu option on devices that allows you to choose a date and time server by IP address. If not, Vizio likely has their own time server that echoes the time from one of the NIST sources.

Stereocraig · 8-Nov-2014, 2:20 PM

Quote:

Originally Posted by timgr

The standard date and time - WWV http://www.nist.gov/pml/div688/grp40/wwv.cfm

There's also WWVH in Hawaii - http://tf.nist.gov/stations/wwvh.htm

There are also internet feeds for standard date and time - http://tf.nist.gov/tf-cgi/servers.cgi

This is likely where your internet-connected devices are getting the data and time. There may be a menu option on devices that allows you to choose a date and time server by IP address. If not, Vizio likely has their own time server that echoes the time from one of the NIST sources.

So, is the OP picking up Fort Collins via OTA?

timgr · 8-Nov-2014, 2:41 PM

Quote:

Originally Posted by Stereocraig

So, is the OP picking up Fort Collins via OTA?

Seriously? I don't think so. I would expect the TV to get time and date via an internet server, not OTA. I don't know whether the sub-band (?) that carries programming information (and closed captioning) also carries the date and time. I suspect it does not, since I don't see a date and time on my not-smart Sony DTV, unless I'm Roku-ing.

Stereocraig · 8-Nov-2014, 2:47 PM

Quote:

Originally Posted by timgr

Seriously? I don't think so. I would expect the TV to get time and date via an internet server, not OTA. I don't know whether the sub-band (?) that carries programming information (and closed captioning) also carries the date and time. I suspect it does not, since I don't see a date and time on my not-smart Sony DTV, unless I'm Roku-ing.

That's why I ask, is b/c he states he's using an attic antenna.

Nor, do I have date/ time on my Bravia. Just the current info and time remaining.
Whatever else it will do, I don't know, cause I only use antennas.

timgr · 8-Nov-2014, 3:09 PM

Looks like the time _can_ be there in the metadata - http://en.wikipedia.org/wiki/Program...ation_Protocol - no mention of date information. Possibly the OP is picking up some discrepancies between the broadcasted value and the stored value?

To the OP - Does the TV have an onboard clock that allows tou to set the day and time, like on a computer? Did you set these values?

Could be that the TV is looking for an internet time server, and defaulting to some internal values when it does not find it? Then correcting the default value from the metadata when it is available? hard to say without knowing how the date/time is implemented on the TV.

d4g4m · 8-Nov-2014, 9:12 PM

TV is connected only to antenna and DISH.
In TV set up, choose language, [to get date/time] choose time zone and enter zip code, [and my question is- who is sending it? one entity or each channel separately] do a channel scan.
Date/time is auto set. There is no manual date/time enter.
The time appears in the top/middle of the channel info pop up box. This function does not work when I switch TV input from antenna to cable. DISH info is totally separate and different. I use antenna because all main channels are HD and DISH does not carry any sub-channels like MEtv, anntennatv, movies, THIS, GETtv, bounce, escape, or my local Sarasota news channel and a few other channels.
Seems that this is a question that no one can answer. I've written to a few stations, a few other web sites, even the fcc.gov No answer from anyone.
ADDITIONAL INFO
I used every imaginable words and phrases searching for info about TV date/time and found nothing. So, thanks to timgr for including the Wikipedia link.
According to Wikipedia, 'program and system information protocol' it is defined in ATSC standard A/65:2013 and A/69 Besides regular programming info, data is transmitted to include 'time' [required by the FCC] All PSIP is required to be sent by every digital TV station. All of the info and data is sent OTA, received by an antenna to the TV receiver and the date/time has nothing to do with the TV being or not being connected to the internet with a router/modem. So, since the TV is losing the correct date/time on every channel, I can only assume that there's a problem with the TV tuner or the date/time IC chip. And back to Vizio tech support.

timgr · 9-Nov-2014, 11:11 AM

From the ATSC document a_65-2009.pdf (I can't get a clean link to it - just Google the name and you can see it), it's clear that the "time" is the absolute time, including the date.

From the format description of the STT,

"system_time — A 32-bit unsigned integer quantity representing the current system time as then number of GPS seconds since 00:00:00 UTC, 6 January 1980."

So it's in the meta-data that each real channel transmits. Supposed to be accurate within a second.

d4g4m · 22-Nov-2014, 1:04 AM

update to original post.
Not only didn't the date/time work properly, but I later discovered, after buying two HDMI cables, that the TV HDMI 1 'arc' to a/v receiver HDMI 1 'arc' didn't work, the HDMI from DVD to tv HDMI 2 didn't work, even adding a digi optical wire.
Icing on the cake. Having the TV for only 3 weeks, it developed a bad pixel [blue]
TV was returned to Walmart. Went to a different store and purchased a Samsung un48H6350 Night and day difference. Looking at the Samsung, I also discoved that the Vizio had a grey haze on the picture. No amount of tweaking settings could correct it. Looks like I bought the lemon of lemons.