Unibrain 830 - Manual (Page 50)

Unibrain Fire-i 530/630/830 Operation Manual Page 44
4.5. Multi-Camera Auto-sync
.
Not supported in 3.75 fps
In applications incorporating Multi-Camera, there is often a need to synchronize the cameras. Multi-Camera Auto
Synchronization is supported utilizing the FireWire bus time cycle register which is connected on the same FireWire
bus without an external signal. Max 3 cameras can be supported for auto-sync on an OHCI card.
The video mode of the camera must be set within the limit of a single FireWire bus bandwidth of 400Mbps. Also,
the maximum shutter value must be set as per the table below, not exceeding the FireWire bus cycle time. Jitter
may occur due to CPU operation timing. In the auto-sync mode, the shutter time and the fps should be set as
follows:
FPS
Fire-i 530x Fire-i 630x Fire-i 830x
Max Shutter Max Shutter Max Shutter
Value Time Value Time Value Time
60 1110 16.5ms - - -
30 1276 33.1ms 1270 32.5ms - -
15 1608 66.3ms 1598 65.3ms 1606 66.1ms
7.5 1760 131ms 1758 129ms 1760 131ms
3.75 1893 264ms 1889 260ms 1893 264ms
To utilize Auto-sync, please set Bit 31 to Auto-sync Enable, and then check the Bit 27 to verify whether it is ready.
Please refer the details as the following table.
0xF2F10018
Auto-Sync Mode control register
Bit 31 : auto sync enable
Bit 30 : SIO enable mode (0 : Custom mode, 1 : IIDC v1.31)
Bit 27 : auto sync complete (read only. 1: ready, 0: not yet auto-sync)
Read/Write
4.6. Asynchronous Broadcasting
Asynchronous broadcasting is supported when using node 63 of the FireWire bus as a target node for an
asynchronous write request. This enables all the cameras to be triggered by software simultaneously. By utilizing
Asynchronous Broadcasting, the user can operate and control all the cameras on the same FireWire bus at the same
time, with a single command.