Why am I having problems getting two DV camcorders to work on the same FireWire (IEEE 1394) card?
A. The cameras are putting the fw bus in S100 mode (100 Mbps). This isn’t anything you can change. According to the spec, there is slightly more than 50 Mbps taken by each camera (for data + overhead). The MS driver is designed to recognize this and only accept one connection. There isn’t an error message returned explaining this. The reason it sometimes works is that fw is peer-to-peer and the root device can be one of the cameras rather than the computer/card. The camera may not enforce the limit and the actual data streamed may not go over the 100 Mbps limit. TMH verified this with the MSFT engineer responsible for testing DV cameras there. For consistent results, you need one fw controller per camera. You can’t control which device is the root device.
