Prosilica GX Technical Manual V2.0.8
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Resolution and ROI frame rates
Resolution and ROI frame rates
This section provides performance information about the impact of reducing the
region of interest on the camera’s maximum frame rate. In addition, because
the Prosilica GX camera offers Dual GigE LAG, the impact of using a single Ether-
net connection versus dual Ethernet connections with the host is compared.
Single port GigE connection with the Prosilica GX
When a Prosilica GX camera is connected to the host computer using a single
Ethernet connection, it behaves like a single port GigE Vision camera. The total
bandwidth available for the camera is 125 MB or 1 Gb. A Dual GigE LAG connec-
tion supported by the Prosilica GX camera offers up to 250 MB or 2 Gb of band-
width.
Bandwidth limiting of frame rate
There are several factors that limit the frame rate of a camera, for example,
input trigger speed and mode, exposure time, sensor readout time, and avail-
able bandwidth. For the following discussion and charts we assume input trig-
ger settings and exposure time are set so as not to limit the frame of the camera.
This leaves sensor readout time, the time to physically output the charge off a
camera sensor, and available bandwidth. In most cases, the sensor readout
time dictates the true frame rate of a camera, unless the amount of transmitted
data exceeds what is available on the GigE interface.
In the example chart below, the frame rate for a 16-bit pixel format is given on
a GX1050 camera. The upper line shows the frame rate in Dual GigE mode, where
no bandwidth limitation occurs. The lower line shows the frame rate in single
GigE mode, where bandwidth limitation occurs after a data threshold of 124
Mb/s. This is the shaded region below, occurring at an image height greater
than 200 pixels.
Figure 34: Illustration of bandwidth limiting: frame rate vs. height for Prosilica GX1050 in single port
GigE configuration - 16 bit pixel format
50
100
150
200
250
300
350
400
0
150
300
450
600
750
900
1050
Fr
ame
Rate [fps]
Height [pixels]
Dual GigE - 16 bit
Single GigE - 16 bit
Bandwidth limited
