HELP...PT won't lock to LTC

[skidd]

I'm using PTIII, 2-888 i/o's, USD, xpansion chassis, PT 4.3, Mac OS 8.1, Powertower Pro 225.
All of the sudden PT won't lock to LTC. It just sits there when I put it on-line. USD sees code, set-up window sees code, and yes I've replaced all the cables and used several SMPTE sourses. It worked fine, I transported the system, and now nothing. Anyone have any insights. I would appreciate anything. Thanks.

[Rail Jon Rogut]

Well you said anything...

1) Have you ensured that you're not set to Generate SMPTE? If so, turn off the option to generate and you should be okay.

2) Do you see the incoming SMPTE numbers in the Session Setup window?

3) Is your session start time perhaps later than the incoming LTC?

Rail

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Recording Engineer

[JBloom]

Did you check under peripherals, under synchronization device is USD and Port should be DigiSerial Port

[skidd]

Thaks for all replies.
1. Not set to generate
2. Yes I see incoming Code on Setup window
3. Session start time is correct.

4. Under peripherals: My options for USD ports are modem and printer. No digiserial.

I am waiting for PT 4.3.1 upgrade from digi so I can try updating firmware from peripherals page.

Are there any utilities that can test my ports?

Thanks again for replies.

[Rail Jon Rogut]

Skidd

If the answer to my #2 was "yes" then your ports should be working okay, and Pro Tools (the app) is seeing the SMPTE values correctly. As to why you're not starting playback...?? Is the cursor positioned after or before the value of the incoming LTC by any chance? Try trashing all relevent prefs and try again.

Rail

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Recording Engineer

[branco]

Is your TC frame rate correct? Double check the master tape for TC frame rate, as it can make the synchronization impossible, too.
Branko

[skidd]

1. Cursor position correct.

2. Frame rate also correct.

I've used at least 6 or 7 different time code sourses, all 30 fps.

Like I said, everything worked fine before, I'm not doing anything different, just doesn't lock to LTC now. If I change the reference to Internal, it will fire at the proper start time, but is not "locked" correctly.

I recently updated myt firmware. No change.

Thanks for all replies.

[Rail Jon Rogut]

Oh... You've got it set to LTC for the time position and Internal for the clock - and it starts at the right spot, but the lock drifts...

In that case, the problem is the BNC cable from the USD to your 888. First thing to check, when you power down the USD, does the 888 change from Slave to Internal? If it always stays on Internal then the clock signal isn't making it from the USD to the 888. If the 888 switches to Slave when you repower up the USD, then I would suspect the BNC cable as either being a) bad or b) too long.

Also make sure that you're feeding 256 x Superclock from the USD to the 888 and not 1 x Word Clock.

Rail

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Recording Engineer

[This message has been edited by Rail Jon Rogut (edited February 13, 2000).]

[JKD99]

Sorry to jump onto someone else's thread, but will I get faster lockup with my USD if I use the Digiserial port instead of the Modem? I've been having trouble with PT taking 10 or more seconds (sometimes) to lock. Slower than my MTP II. Is the Digiserial port "better?" OS8.6, PT4.3.1. Mix++, Blackburst Ref, Superclock to 888|24.
Thanks!

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Joe Milner
Puget Sound

[This message has been edited by JKD99 (edited February 13, 2000).]

[This message has been edited by JKD99 (edited February 13, 2000).]

[DigiTechSupt]

Skidd,

I have seen this when the clock source was unstable. What is the clock ref set to? If you have House sync (Black Burst) connected to the video ref jack (not the video in), your clock ref should be set to video and you should also be using the 75ohm terminator on the parallel video ref jack. Also, the lock light should be solid. If not, you either don't have stable clock or it's not terminated properly.

If you are not clocked to Black, your clock ref should be set to LTC. In this mode, your USD will extrapolate a sample rate from the incoming time code. If the time code coming in is not stable, you could get the same result. Also pertinent here, as Rail pointed out, is the Slave Clock connection between the USD and your 888.

As Rail suggested, you might also trash the PT prefs, digisetup file, and USD prefs. If you're really stuck, you might try updateing the USD firmware using the USD Setup app. I have also seen serial port conflicts cause this problem. You can reset your ports by holding down apple/option and open the chooser. You should hear a chime.

Joe - On the 24bit systems, you should definately be using the DigiSerial Port. It is a direct input to PT with the TC.

One last note...the DigiSerial Port does not exist on PTIII hardware. PTIII users should be using the Modem port for the USD.

Jake Schaefer
Digidesign Product Specialist

[This message has been edited by DigiTechSupt (edited February 14, 2000).]