49
Alvium USB Cameras User Guide V3.3.0
Specifications
Exposure time and frame rate
Stated values were measured for a maximum bandwidth of 375 MBps for Typical
operation, using the following test setup:
Exposure time behavior regarding ExposureMode
This section informs about how exposure time behaves in the different exposure
modes.
All Alvium cameras have an exposure time offset. The exposure time offset and the
exposure time increment depend on sensor and camera characteristics. Both, the
exposure time offset and the exposure time increment, can change if
Width
,
PixelFormat
, or
DeviceLinkThroughputLimit
are changed. See
Component
Property
Desktop workstation Dell Precision T5500 Precision (EHW400)
Chipset
Intel X5520
CPU
Intel Xeon X5670 (6 cores)
CPU frequency
2.93 GHz
RAM
12 GB
Graphics controller
NVIDIA Quadro FX 580
USB controller
Delock U3 PCIe 1XG205-1S Rev. 1.1
(2-port USB 3.0 to PCI Express x1 Gen 2 with Renesas
chipset)
Operating system
Windows 7 Ultimate 64-bit SP1
Measured by
Oscilloscope
Measured signal
ExposureActive
Table 15: Test setup components
Bandwidth, exposure time values, delays, and ROI frame rates
•
The
default bandwidth
for Alvium USB cameras is 200 MBps. For some
models, you can achieve higher frame rates by increasing values for
MaxTransferSize
and
DeviceLinkThroughputLimit
•
Available values and increments for
exposure time
depend on other controls,
such as
DeviceLinkThroughputLimit
•
For
delays
Exposure start delay = exposure area – exposure time.
•
Calculation of maximum
frame rates for different ROIs
for Alvium USB
cameras does not allow to give a formula.
on page 50 defines
the conditions for measuring ROI frame rates.