Hardware trigger cameras / master and slave(s)
To synchronize industrial cameras the I/O port of the industrial camera is required. A master camera will hardware trigger it’s slave cameras to assure perfect synchronization between all cameras. In this example we explain how to connect 1 master camera to 3 slave cameras. As a result the setup will have 4 industrial cameras perfect synchronized.
How to synchronize industrial cameras?
The schematic below illustrates how to synchronize three slave cameras with one master camera using hardware triggering. An external power supply is required for this setup, with a voltage range between 5Vdc and 24Vdc. In this example, a 12Vdc external power supply is used to ensure stable operation.
The Line 1 output of the master camera can handle a maximum of 25mA, while each Line 0 input on the slave cameras requires 7mA to function correctly. This means a single master camera can synchronize up to three slave cameras (7mA × 3 = 21mA) via the trigger input.
If you need to synchronize more cameras, please get in touch with us so we can explain how to use the other I/O available to synchronize a maximum of 10 industrial cameras.
Calculation of resistor to limit the current for the synchronized cameras
To limit the power supply output current to protect the camera electronics, a resistor is required. The value of this resistor depends on the external power supply voltage and the number of slave cameras connected. In our example, we are synchronizing 3 slave cameras with one master camera using a 12Vdc external power supply. The resistor value is calculated as follows:
Resistance (R) = Voltage (V) Current (I) (Ohm)
- 1 Slave Camera: The current will be between 7mA and 25mA, with a preferred value of approximately 12mA.
- 2 Slave Cameras: The current will be between 14mA and 25mA, with a preferred value of approximately 17mA.
- 3 Slave Cameras: The current will be between 21mA and 25mA, with a preferred value of approximately 24mA.
For this setup, using a 12Vdc external power supply to synchronize the cameras, the recommended resistor values are as follows:
- 1 slave camera: 1000 Ohm resistor
- 2 slave cameras: 680 Ohm resistor
- 3 slave cameras: 470 Ohm resistor
In the schematic provided above, where 3 slave cameras are connected, a 470 Ohm resistor is used to ensure proper synchronization of all 4 cameras.
I/O connector to hardware trigger an industrial camera
The Input/Output (I/O) connector of the industrial camera is essential for triggering the slave cameras from the master camera. This connector allows for precise synchronization of the cameras through hardware triggering. Below is the pinout of the I/O connector used for this purpose:
Programming Cameras for Synchronized Camera Mode
To enable synchronization, the Galaxy SDK is required. Follow the five steps outlined in the article to install the machine vision camera and ensure that the SDK is properly set up.
Master Camera Setup:
- The master camera will operate in free-running mode. Each time the master camera captures an image; it will activate the output on Line 1.
- To configure this in the Galaxy SDK, connect to the master camera and navigate to: Features > Device > Remote device > Digital IO-Control.
- Set Line Selector to “Line 1” and Line Source to “Strobe”.
Slave Camera Setup:
- Next, connect to the slave cameras one by one. The slave cameras must be configured for hardware triggering.
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For each slave camera do:
- Go to Features > Device > Remote device > AcquisitionControl.
- Set TriggerMode to “On”.
- Set TriggerSource to “Line 0”.
- Ensure all other settings are configured as shown.
Once this setup is complete, the cameras will be properly synchronized, with the master camera triggering the slave cameras each time an image is captured.
NOTE: keep exposure time of the slave cameras less or equal to the master camera.