This is a wierd one. I've been using this setup on a live TV show running click to band rhythm section and additional sequencing to two other stereo pairs out of the Traveller. It can be fine all day - 5/6 hours - then when it comes to the broadcast, I can check the track several times - all is fine - then at some point, it will just not send audio from the outputs of Logic, and the Traveler shows and outputs nothing. Re-launching Core Audio does not resolve the issue, nor does re-booting the Traveler, factory resetting the Traveler, or re-launching Logic Pro. I have re-created the issue at home by leaving the configuration on overnight. In the morning the issue occurs - it appears to be a time thing, not dependant on whether the program is being used or not i.e. it can happen during use as well as after a long period of inactivity. I have not tried previous versions of logic to work around this yet, but I used to use 7.0.1 with MOTU Firewire driver 1.2.5 (2005-05-10) before and don't recall the same issue. This issue occurs in Logic 7.1.1 with MOTU drivers 1.2.5 (2005-05-10) and 1.4.1 (2006-02-28). I have nothing else running, e.g. Widgets, Screen Savers, No Energy Saver settings, all non-essential software is disabled/closed. It occurs with or without firewire bus power or a separate power supply. If I swap back to Built-in audio as my Audio driver I can play stuff through the internal speakers, but if I then switch back to MOTU Traveler as the Audio device the problem is still there. The only way out is to re-boot the machine - which is re-loading the driver, I guess.

Any help would be gratefully received

A few things out of my head (I'm sick these days, don't ask much, and my net connection is a mess so…)

- Are the power mains clean? No spikes?
- Is it at random in timing or more or less after always a few hours?
- in the energy saving features which cause some problems, install the CHUD tools from the developer part of you install CD/DVD of OS X (which version of OS X are you running btw?), it'll install a prefpanel in the system preferences called Processor, in it disable the "nap" checkbox and see if it occurs still (I don't know if it will do something, I'm making some gesses…)
- still in the energy saving setting stuff, but the energy saving pref panel this time, is the system allowed to go down? the drive to spin down? whatever… to be precise in full, just in case…
- is you powerbook regularly maintained? (BSD scripts, permissions, disk repairs, caches cleaned etc. using OnyX for example) to be sure it's not something trivial.

As the problem seems rather localized somewhere along the firewire, I'd try a PMU (power management unit) reset too. In case something fishy lurks somewhere. (see the manual of the powerbook)

My guess is it's a driver bug. It sounds like a classic clock-rollover problem. After some period of hours, the clock value gets too large for whatever time-tag format the MOTU driver uses. I don't know what time-tag format they use, but I played with a few possibilities, and one that I came up with overflows in slightly under 6 hours. I wonder if the 828s (which I believe use the same driver) also have the problem. If I had mine, I'd try it, but my rig is not running right now.

Write to MOTU. Tell them what versions of everything you are running and how you created the problem. Since you can reproduce the problem at will, it should be easier to get their attention.

My suggestion for the show would be to reboot about an hour before show time. This way, you have time in case something goes wrong during the reboot.

Thanks Cornutt

No reply for over 3 days from MOTU, but armed with your info, I'll hassle them again with more details, and hope they take notice. Since your reply, I've tried it with iTunes instead of Logic, and I get the same issue!
Many thanks

Slack