Problem with Daisy Chaining MOTU Ultralite to External HDD

Posted: Sun Jun 01, 2008 6:09 pm

Hello brothers of sound, first of all, excuse my poor english.

I have been asked to do field-recording for a university film project in two weeks. The thing is I'd like to daisy-chain my firewire interface to a firewire external hdd. When using my interface DC powered or bus-powered (firewire) there's no problem at all, the same goes to my External HDD. But when I daisy chain: MOTU -> HDD -> Laptop or HDD -> MOTU -> Laptop, either devices seems to be not available to OSX which is a huge problem for me as I have little space on my internal HDD.

My equipment is:
MOTU Ultralite (2006)
Apple Macbook Pro (2008)
Macally Firewire External HDD (2008)

Any insight on how to solve this, please let me know.

Thanks in advance,

Pablo Rubio

Posted: Sun Jun 01, 2008 9:32 pm

It reads that the Motu and your hdd enclosure are rated IEEE 1394(firewire 400).

But the laptop has a 400 and an 800 port, 800 being backwards compatible.

Put the laptop first in the chain.

You could start with the 800 port on the laptop and chain out from there.

I am not a Mac user.

Posted: Mon Jun 02, 2008 12:29 am

Hello Space, thanks for your reply.

When you tell to put the laptop first... well, isn't it the same as I have explained above?

I mean:

MOTU -> HDD -> Laptop
HDD -> MOTU -> Laptop

isn't the same as:

Laptop -> MOTU -> HDD
Laptop -> HDD -> MOTU ???

Pablo R.

Posted: Tue Jun 03, 2008 5:26 pm

How are you powering these things in the field?

Posted: Tue Jun 03, 2008 6:56 pm

As you can imagine, with the gear I intend to do the recording there's not much portability (Laptop 15.4" + Interface, etc...) The recording itself (to the purist) could hardly be described as field-recording as I won't be following anybody with a boompole, field-mixer, etc. Instead, the shots will be stationary and I'll have my setup on a table, connected to a battery system. That's pretty much how things are going to be.

Pablo R.

Posted: Tue Jun 03, 2008 7:31 pm

"FireWire cable power is present anytime the AC adaptor is powering the system, including shutdown. The MacBook's six-pin FireWire connector provides unregulated 9 V to 12 V power with a maximum load of 0.75 A.

Output voltage depends on the system's battery charge level. Output voltage may be lower when the battery is not fully charged. "

http://developer.apple.com/documentation/HardwareDrivers/Conceptual/

Maybe this is the issue?

Posted: Sat Jun 07, 2008 7:10 am

Thanks for your time Space. Hmm, yeah the FW port at the macbook is on unless the system is in sleep or shutdown. But, thats not the problem. My problem is that the motu should stop receiving power from the FW port, from the moment I connect the power supply to it. At least that's what the manual says, that the motu will follow the higher voltage as a power source.

P. Rubio

Posted: Sat Jun 07, 2008 11:02 am

Not sure about the Ultralite but on the Traveler there is a switch on the side that turns the bus power on or off. If it doesn't automatically switch, maybe there is a manual one somewhere? Then you wouldn't have trouble getting enough power for both the interface and the harddrive.

Posted: Mon Jun 09, 2008 7:12 pm

Hmm yeah, there's the manual & it doens't have a switch for DC power. I ordered a 9-to-6 pin FW cable to try with the motu... If there are still problems I'll get a FW800 HDD.

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