xiMU - Technical Manual Version 2.10
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"usb20pktsize"=dword:00000000
4.7.3.
Bandwidth control
Different USB host controllers can have different maximum data throughputs. The default behavior of the API is to measure the
value of the maximum data throughput of the host controller (available bandwidth) when the camera is opened and limit the data
rate (bandwidth limit) to the 80% of the maximum measured value. In case multiple cameras are connected to the same USB
controller or target data rates higher than 80% of the maximum throughput are needed, application can manually change the limit
the data rate by setting the value of the XI_PRM_LIMIT_BANDWIDTH parameter. For more information see our
and
4.7.4.
USB HUBs
The maximum possible bandwidth is limited when the xiMU camera is connected through a USB hub. If possible - connect the
camera directly to the USB port of the PC.
4.7.5.
Using multiple MU9 cameras
In case multiple MU9 cameras are used, each camera must be connected to a separate USB2 controller, otherwise streaming will
not work properly and the user will observe the "Fifo overflow" message in debug output of the application.
4.8.
Connecting Two MU9 Cameras with Synchronized Acquisition
Two or more MU9 cameras can be connected with synchronized acquisition of images. To decrease the delay between images
the cameras should be interconnected via the strobe/trigger signal.
4.8.1.
Interconnect Cameras
MU9Px-MH cameras could be synchronized from external source. In this case electrical characteristics in GXn DC electrical
characteristics need to be observed. In similar way cameras could be connected with each other. In this case one camera will be
used as master to trigger all slave cameras. As the output strength of GPO is limited maximum 2 inputs of MU9Px-MH could be
connected to one output as depicted on figure 4-11. This setup ensures low latency between two camera exposures. Latency
should be less than 10us.
Two cameras interconnection
figure 4-11, connecting two MU9 cameras in MASTER-SLAVE (SLAVE on right)
Interconnect the cameras with 2 signals:
•
GND (pin 3 on Trigger Plug of MU9 Patch cable [see
o
Connect this pin to same pin on the other camera (GND)
•
GX2 (pin 1 on Trigger Plug of MU9 Patch cable [see
o
Connect this pin to pin set as trigger input on other MU9 camera (GX1)
o
For connecting different model of XIMEA camera signal conditioning may be needed.
xiMU
xiMU
GND
GND
GX1
GX2
GX2 set to exposure active neg
GX1 set as trigger input rising edge
