Synchronous image acquisition

Three primary methods exist to synchronize the capture of multiple cameras. The first uses software trigger; the second method uses hardware trigger and an external trigger signal; and the third method uses the digital output of one camera to hardware trigger a group of cameras.

Software Trigger

The software trigger method does not require any additional hardware setup. Simply connect your uEye cameras to the PC. All uEye cameras except the USB 2 uEye XS and USB 3 uEye XC have access to a software trigger mode. Due to the nature of operating systems, software triggered mode has an indeterminist delay between the software command and start of image capture. Applications that require more than 10s of milliseconds precision should use one of the other methods below.

For details on the setup, please refer to the uEye MultiCam Demo that is installed with the IDS Software Suite on Windows systems.

Software trigger – trigger acquisition through software commands
Software trigger – trigger acquisition through software commands
Hardware trigger – hardware trigger the cameras using the trigger inputs and a single trigger source
Hardware trigger – hardware trigger the cameras using the trigger inputs and a single trigger source

To test the hardware trigger setup, use uEye Cockpit. Open all of the cameras in separate instances of the program, and set the cameras to ‘continuous trigger’ mode using the button on the toolbar.

The uEye Cockpit toolbar
The uEye Cockpit toolbar
Switching the trigger mode
Switching the trigger mode

Open up the properties window (the wrench icon: ) and navigate to the “Trigger” tab. Change the mode from “Software” to “Falling edge”.

Master/Slave Hardware Trigger

In this option, all cameras are configured to be used in triggered mode. Then, the flash input, or a GPIO is configured to trigger all cameras simultaneously.

Master/slave setup – trigger all cameras off of a digital output of one “master” camera
Master/slave setup – trigger all cameras off of a digital output of one “master” camera
Example wiring of the flash output
Example wiring of the flash output

To test the master/slave hardware setup, use uEye Cockpit. Open all of the cameras in separate instances of the program, and set the cameras to triggered mode using the button on the toolbar.

The uEye Cockpit toolbar
The uEye Cockpit toolbar
Switching the trigger mode
Switching the trigger mode

Next, open up the properties window (the wrench icon: ) and navigate to the “Trigger” tab. Change the mode from “Software” to “Falling edge”.

All of the cameras should stop acquiring frames. Now switch to the “Input/Output” tab in “Properties”. Under the flash output group box, change the output to “Constant high”, then to “Constant low”. This creates a falling edge all of the cameras trigger off of. You should see a new frame captured.

The flash output
The flash output