Frequently Asked Questions Datavideo VP-322 DV Repeater
Q: What we are trying to do is export from a mac (using iMovie, finalcut) to 2 dvd recorders at the same time. Unfortunately this under OS X does not work. Using OS 9 and iMovie 2 this works fine. We are using the datavideo DV repeater. This obviously works fine with DV camera's as well as OS 9 but not with OS X. For example: We are using 1 Mac to stream video to 2 DVD recorders at the same time.
A: The Datavideo "DV Repeater" is just a hub, a pass-through device that doesn't alter the 1394 bus-traffic in any way. There is a difference between how the FireWireDV components in OS-9 verses OS-X handle the transmission of DV.
  First, realize that 1394 allows for 64 different isochronous "channels"
to be used for streaming. A transmitter device needs to select one of these
64 channels for the stream it's generating, and a "listener" device typically only listens to one isochronous channel at a time. For AV/C devices (such as DV devices), they either need to be told to listen on a specific channel (using what is known as CMP, "Connection Management Protocol" to establish point-to-point connections), or if no point-to-point connection is made to an AV/C device, it usually defaults to listening on channel 63.
  The difference is that OS-X video-editing applications now do the more correct thing of allocating a specific isochronous channel, and using point-to-point connections between the Mac and a target DV device. The older OS-9 code just transmitted on channel 63, which is the default channel DV devices listen to when they don't have a point-to-point connection. The change to using a point-to-point connection prevents multi-device stream conflicts, and allows for more flexibility in the future (i.e. support for multiple devices sending/receiving data on different isochronous channels, all on the same bus), but applications need to be designed to support this single-stream/multiple-listener scenario which is available in OS-9, which Apple's current video editing apps under OS-X don't support.
  As as work-around, the AVCBrowser application (part of the FireWire
SDK) is a tool that shows a list of all connected AV/C devices (including DV devices), and lets you open a control panel for each device and view/make/break point-to-point connections, as well as send AV/C commands.
Using this tool, it should be possible to establish a point-to-point connection to the "input plug" on the second DV device on the bus, selecting the same isochronous channel that the video editing app is using to transmit to the first DV device on the bus. If no other isochronous channels are in use on the bus, the customer can probably assume that the isochronous channel number 0 is being used (though, to be sure, he could first select the other DV device with AV/C browser and view the state of it's current "input plug" connections, including the isochronous channel number).
Understand that this work-around is a hack, and is not a normally supported Apple procedure. That being said, it can be made to work if done correctly, but is probably not the best solution for somebody who is doing this over and over as part of their daily business.
Q: Can the VP-332 be used to power Datavideo Inline repeaters in a long DV cable run?
A: Yes, The VP-332 can supply enough power to operate our VP-314 Inline DV repeaters.