How to synchronize industrial machine vision cameras?
To synchronize industrial machine vision 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.
Technical schematic of a synchronized camera setup:
The schematic below shows how to trigger 3 slave cameras from 1 master camera. An external power supply is always required. The external power supply voltage range should be between 5 and 24V. In our example we will use a 12V external power supply for the synchronized camera setup.
The power Line 1 output can withstand 25 mA max. A Line 0 input(s) needs 7mA to work. Thus maximum the master camera can trigger 3 slave cameras (7*3=21mA), using the slave cameras trigger input Line0.
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 extern powersupply voltage and the number of slave cameras connected. In our example we synchronize 3 slave cameras with one master camera using a 12V external power supply. The calculation of the resistor is:
Resistance = Voltage / Current (I)
1 slave camera -> current between 7 and 25mA, preferred approx. 12mA
2 slave cameras -> current between 14 and 25mA, preferred approx. 17mA
3 slave cameras -> current between 21 and 25mA, preferred approx. 24mA
The advised resistors using a 12V external powersupply to synchronize the industrial cameras are:
1 Slave camera, a 1000 Ohm resistor
2 Slave cameras, a 680 Ohm resistor
3 Slave cameras, a 470 Ohm resistor
In the schematic above there are 3 slave cameras, therefore a 470 Ohm resistor is used to synchronize in total 4 cameras.
I/O connector to hardware trigger an industrial camera
The Input/Output (I/O) connector of the industrial camera is used by the master camera to hardware trigger the slave cameras. The pinout of the I/O connector is:
Programming the cameras in synchronized camera mode
To program the cameras for synchronization, the Galaxy SDK is required. Follow the article 5 steps to easily install a machine vision camera, to make sure that the SDK is installed correctly.
The Master camera will be in free-running mode. Every time the master camera captures and image, it will make line 1 output high. To program this in the Galaxy SDK program connect to the master camera an go to: (Menu :Remote device/DigitalIOControl)
Select the Line1, change LineSource to “Strobe”
Next step, connect to the slave cameras one by one. The slave cameras need to be programmed as hardware triggered and the triggersource should be line0. To do this:Go to Menu: Remote device/AcquisitionControl
Change TriggerMode to “ON” and TriggerSource to line0. Make sure the other settings are as shown.