USB Problem

Multitrack recorders, controllers, and other studio equipment
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granam
Posts: 6
Joined: 05:58, 29 August 2006

USB Problem

Post by granam »

I've recently purchased three Roland units - an MC808 groovebox, an Edirol PCR-M80, and an RD700-SX.

All three of the units have a USB 2.0 connection, which I've linked into a USB 2.0 hub. However none of it seems to work unless I also introduce a computer into the situation. In other words, I can't seem to communicate directly from one Roland USB unit to another, without having to go through a computer.

Do I have something configured wrong, or is that the way USB is designed to work?

Regards,
Brian
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Artemiy
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Re: USB Problem

Post by Artemiy »

All of these devices are USB slaves, but USB works with a slave - host connection. Consider this, what will happen if you connect 808's output to RD's output? Nothing really useful. Same with USB - there are slaves and hosts. 808 can act as a USB storage device or as a MIDI device, PCR-M80 and RD can also work as USB MIDI devices.
granam
Posts: 6
Joined: 05:58, 29 August 2006

Re: USB Problem

Post by granam »

So it would seem that USB is not a very good way of transporting MIDI data. MIDI can go point-to-point, but it appears that when it's transported via USB, it must be routed through a computer. MIDI is peer-to-peer, but what I'm understanding from your reply is that USB is master-to-slave.

I'm not able to connect all of my USB instruments to a hub, and then have, for example, the USB MIDI out on the EDIROL PCR-M80 send messages directly to the USB MIDI in on the RD700-SX or the MC808. USB MIDI out messages from any of the instruments must first go to the USB MIDI in on the computer, and the computer then resends the messages from its USB MIDI out. Seems like a very inefficient way of doing things. Why add latency to the system by routing all the MIDI through a computer?

Regards,
Brian
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V-CeeOh
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Joined: 18:13, 28 September 2004
Location: Portugal

Re: USB Problem

Post by V-CeeOh »

Hi granam

"... and then have, for example, the USB MIDI out on the EDIROL PCR-M80 send messages directly to the USB MIDI in on the RD700-SX or the MC808"

And why would you not just use the MIDI conections? - Its what they are there for. It appears to me that you're over complicating things. If you wanna have a MIDI "talk" use the MIDI conections. If you want to have a "data talk" then you'll use the USB ports.
Remember that MIDi firts began when there was no such thing as USB and that a "sinth-PC" talk was much harder to do, "MIDI over USB" comunication has been imployed in order to make things easy avoiding, for example the need for multiple cables and interfaces. But, MIDI is still the most reliable when you want to put several sinths talking. However , for large amounts of data, such as those needed for samples, USB is better and easier to integrate in a PC environement.


o - ...just could not afford the 8
(
\_/
hear what I've done with the 7
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