Specifications
33
Manta Technical Manual V7.9.0
Frame memory
Normally, an image is captured and transported in consecutive steps. The image is
taken, read out from the sensor, digitized and sent over the GigE network. Manta
cameras are equipped with an image buffer. The memory operates according to
the first in, first out (FIFO) principle. Specification tables for each camera show how
many frames can be stored by each model.
Resolution and ROI frame rate
ROI frame rate is listed after the specification table. The resulting frame rate from
changing sensor height from full image to a single line. Unless otherwise noted,
sensors do not give an increase in readout speed with a reduction in width.
However, in cases where a camera is limited by frame rate due to bandwidth
restrictions, a reduction in width will give a frame rate increase. Cameras with a
burst mode frame rate are able to output more data than the maximum available
bandwidth (124 Mbit/s), and will see a frame rate increase with a reduction in
width.
Number of frames
The number of frames (
StreamHoldCapacity
) depends on resolution, pixel
format, and GigE Vision Streaming Protocol (GVSP) packet size. The stated number
of frames is typical for:
•
Full resolution
•
Mono8/Bayer8
•
GevSCPSPacketSize
=
8192
bytes per packet
Resolution and ROI measurements
•
Data was generated at full resolution using
StreamBytesPerSecond
= 124
Mbit/s (full bandwidth) and an 8-bit pixel format. Frame rate may be lower if
using network hardware incapable of 124 Mbit/s.
•
For maximum speed advantage on quad-tap CCD sensors, ROIs are center
image, where
OffsetY
= (full sensor height – ROI height)/2.
•
There is no frame rate increase with reduced width unless otherwise noted.
•
BinningVertical
is vertical row summing on CCD before readout. The
frame rate for an ROI at the same effective height as binning will be slower
because the CCD still needs to read out the “fast readout rows” in ROI mode.
Frame rate for CCD sensors
The frame rate is a theoretical maximum frame rate (frames per second) of the
CCD sensor according to the given formula.
Frame rate and readout
Although the sensor is capable of higher frame rates, readout is limited by GigE
bandwidth and exposure value. You can improve frame rates with a reduced
region of interest and shorter exposure values.
