8.Features
© China Daheng Group, Inc. Beijing Image Vision Technology Branch 82
2) Frame rate (Unit: fps)
F =
10
6
𝑇
𝑓
It is recommended to use the frame rate calculation tool, the frame rate will be calculated
automatically after the configuration parameters are filled.
8.5.2. USB Interface Bandwidth
The theoretical bandwidth of the USB interface of MARS-U3 series camera is 400MBps, but actually the
value will decrease with the type of the USB3.0 host controller, the version of the host controller driver, the
wastage of the HUB and the host performance. The user can refer the test result of the interface bandwidth
in <TN-USB3.0 host controller bandwidth and CPU utilization> document.
8.5.3. DeviceLinkThroughputLimit
The MARS-U3 series camera provides bandwidth limit function, in order to control the upper limit
bandwidth of single device. When the DeviceLinkThroughputLimit is greater than the current device
acquisition bandwidth, the current device acquisition bandwidth will not change, when the
DeviceLinkThroughputLimit is less than the current device acquisition bandwidth, the current device
acquisition bandwidth will be reduced to the limit of the DeviceLinkThroughputLimit, the current device
acquisition bandwidth can be read from the camera.
When the camera is working in trigger mode, the bandwidth limit will restrict the maximum trigger frequency.
Example 1:
The MARS-1230-23U3M/C is working in continuous mode, the DeviceLinkCurrentThroughput is
35000000Bps,
the
DeviceLinkThroughputLimit
is
40000000Bps,
and
then
the
DeviceLinkCurrentThroughput is still 35000000Bps. If the DeviceLinkCurrentThroughput is 70000000Bps,
the DeviceLinkThroughputLimit is 40000000Bps, and then the DeviceLinkCurrentThroughput will be
40000000Bps.
Example 2:
The MARS-1230-23U3M/C is working in trigger mode, the DeviceLinkCurrentThroughput is
300000000Bps, the maximum trigger frequency is 23.5Hz @ full resolution (8bit), when the
DeviceLinkCurrentThroughput is 35000000Bps, the maximum trigger frequency is 2.8Hz @ full resolution
(8bit).
Model
Min. of
DeviceLinkThroughputLimit
Max. of
DeviceLinkThroughputLimit
Step of
DeviceLinkThroughputLimit
MARS-1230-
23U3M/C
35000000Bps (8bit)
400000000 Bps
1000000Bps
70000000Bps (8bit)
MARS-1231-
32U3M/C
35000000Bps (8bit)
400000000 Bps
1000000Bps
70000000Bps (8bit)
