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View Full Version : 2 camemeras connected to the same FireWire bus



elia
August 29, 2006, 11:11:22
I use 2 camemeras (DFK 31BF03). Both cameras is connected to the same FireWire bus.
My vb code is:
If Not ICImagingControl1.DeviceValid Then
ICImagingControl1.ShowDeviceSettingsDialog
ICImagingControl1.LiveStart

If Not ICImagingControl1.DeviceValid Then
MsgBox "No device was selected."
Unload Me
End If
End If

If Not ICImagingControl2.DeviceValid Then
ICImagingControl2.ShowDeviceSettingsDialog
ICImagingControl2.LiveStart

If Not ICImagingControl2.DeviceValid Then
MsgBox "No device was selected."
Unload Me
End If
End If

but sometime get the error msg:
" An unexpected DShowLibException occured: Error = startLive falied.
VideoCaptureDevice = DFx 31BF03 1
videoFormat = BY8 (1024x768)
in file : ".\GrabberPImpl.cpp" at line: 435 "

Why?

can u help me
thanks

Stefan Geissler
August 29, 2006, 11:19:34
Hi,

You may should tyke care about the FireWire bandwith. BY8 at 30 fps and UYVY at 15 fps use 70% of the available FireWire bandwidth. Thus two cameras will try to allocate 140% of FireWire bandwidth. You should use a lower frame rate, then both cameras will run connected to one FireWire board.

(Keep in mind: Not only the image data but also header data for each transfered block are transfered through FireWire.)