Allied Vision Alvium Series - Frame rates with rolling shutter sensors

70Alvium USB Cameras User Guide V4.6.1
Specifications
Bandwidth: Data is provided for 200 MByte/s, 375 MByte/s, and 450 MByte/s,
using 8-bit, 10-bit, and 12-bit sensor ADC readout modes, depending on model
abilities. The default value for
DeviceLinkThroughputLimit is 200 MByte/s for
Alvium 1800 U cameras measured as average sensor readout.
Frame rates with rolling shutter sensors
The following table shows how the shutter mode impacts available frame rates.
Reducing the area for ROI reduces readout time. The values in Table 17 apply only
if exposure time is shorter than readout time.
Sensor type Shutter mode Trigger mode
Frame rates at full
resolution* ROI frame rates
All models, except
for...
Global shutter (GS) Freerun 100%
Increased values
Global shutter (GS) External trigger 100%
1800 U-500,
-501 NIR
Rolling shutter (RS) Freerun 100%
Increased values
Rolling shutter (RS) External trigger >50%
1800 U-1240
Rolling shutter (RS) Freerun 100%
No increase
Rolling shutter (RS) External trigger >99%
Global reset shutter (GRS) Freerun >99%
Global reset shutter (GRS) External trigger >99%
1800 U -2050
Rolling shutter (RS) Freerun 100%
Increased values
Rolling shutter (RS) External trigger >99%
Global reset shutter (GRS) Freerun >99%
Global reset shutter (GRS) External trigger >99%
*Related to the values for maximum frame rates stated in the specification tables for each model.
Table 17: Frame rates depending on shutter and trigger modes
Achieved frame rates may not match specified values
• Some sensors have an exposure start jitter that may reduce maximum frame
rates.
• Your individual setup may cause delays in data transmission.
Bandwidth adjustments
Consider the bandwidth available for camera payload depends on your individual
hardware, the operating system, software and drivers, and your application. We
recommend you to adjust
DeviceLinkThroughputLimit and MaxTransferSize
to your requirements. See Host setup and bandwidth on page 306.