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I'd really shocked if it wasn't within the RS-232 voltage spec, though (you could easily enough measure to be safe).

Sure, ideally you'd know the format. If anything's clear, we know it's not SMPTE timecode, since there's a special jumper for that. But you don't even really need to know the format (even if it is not RS-232, you don't really care). All you have to do is timestamp the data from the reader and look at the differences, and see if the rate of timecode coming from the reader changes. If they're opaque blobs or if your UART shows them up as "~~{{{{", as long they're regular, then you can make a useful measurement if you look for variations in that regularity.

But if the LED is flashing, then you have even more reason to suspect a problem with the reader. Assuming your print doesn't have a problem with the timecode, you should never have a flashing LED...

--jhawk

I posted a lot of information for you in the first page of this thread! I also asked you to email me. I prefer to not handle on-going discussions or make lengthy postings on message boards.

Drifting sync is not caused by the length of the cable. It is possible for it to be caused by a bad reader but I have never seen that. If the reader has a problem, its green LED will start blinking. The voltage to the reader's LED should be checked and recalibrated when necessary. Details are posted in our online techcenter at www.dtsonline.com/cinema

It is possible for the player's timecode board, D422, to have a problem. I have seen that but it is not very common.

If sync drifts, it is most likely to be a print problem.

As mentioned in the first posting, if the entire print is out of sync, then either (1) the threading pattern has changed -or- (2) your OFFSET is not set correctly and needs to be recalibrated.

If only part of the print is out of sync, then you have either a print problem or hardware problem. The way to tell is if you move the print and the problem stays with the print, the print is bad and needs to be replaced. If the problem stays with the hardware, then you need to look at that.

The other possibility (sync temporarily off) is that is the way the sound track was intended.

I believe you said that you moved the reader and the problem followed the reader. If that is true, then the reader should be swapped (contact your local dealer for a repair/exchange).

If replacing the reader does not help, then the D422 timecode board inside the player is bad and should be replaced.

For more inforamtion, PLEASE SEND ME AN EMAIL.

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One of the other techs here at work was reading this thread and reminded me of another possibility (HI MIKE!). Be sure to verify that the speed of your projector is constant. If the projector speeds up or slows down, it could effect the sync.

Have you checked the firmware version yet?

However, the tech was knowledgeable enough to ponder whether it might be a power-phase issue. Bingo! If the Christies use the power phase to determine their speed, then that may well be it.

How to check the speed of the projector? Well, since quartz crystals are very accurate, I could use a quartz crystal-based battery-operated microcontroller circuit to count frames or perforations / sprocket holes and graph the frame-rate throughout the performance. If I graph that, I will post the graph here. Question to the Christie gurus: where can one find a frame/perf timing signal from the P35GPS that we can use to time it?

At the end of the day... the reader either works or it don't! no if's no but's so that can be counted out.

When you think about it if the projector is running too fast, or for that matter too slow.... or even irregular how can the DTS keep up with it! The time code is fine, it knows where it is in the film. thats the easy bit. But what does the DTS unit do. Does it play back the sound faster or slower.... can it maintain the original pitch of the audio while its trying to keep pace with the position it should be in the film or does it just drop frames to keep sync.

But that's irrelevent. There is no requirement for consistent frequency of power between the DTS player and the timecode reader -- the player synchronizes itself to the pulses from the timecode reader. (I have an unfortunate problem of 2 projectors that run at slightly different speeds, and DTS handles it just fine, though in some cases you can hear the pitch bend across the changeover.)

So even if you run your projector at 25fps, that's not going to cause this problem. And ground is even less plausible to be relevent.

And no, the DTS 6D firmware is a socketted EPROM, not an EEPROM. To reprogram it you would need to remove it from the socket and burn it in an EPROM burner, and at that point, you'd be much better off just getting DTS to ship you a new IC.

--jhawk

I had a free firmware upgrade from DTS, contact Karen and she will help you. However, since both player went out of sync in the same moment I do not believe that firmware upgrade will help you in this case.
Perhaps proj speed is a thing to check.
Be sure that print enters the reader freely (it doesn't have violent pull that can cause the reader to see the print changing its velocity).

I had problem for a reader not firmly screwed to the projector.

Bye

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