Synchronized Capture with PL-B Cameras

Description

Synchronized image capture can be performed between two or more PL-B cameras, with simple cabling.  See the diagram below to view the cabling diagram and refer to the hardware specs regarding the machine vision connector, if needed.  In essence, the programmable output from one camera is used as an input trigger into itself, and one or more other cameras.

Cabling 

The PL-B cameras have a 9-pin Micro-D connector in the back for external control. This diagram shows the pin-outs on that connector, and how they can be connected together to make synchronised capture work. While it is best to use a custom cable, with Micro-D connectors for any production system, it is possible during prototyping to test this scenario using a few simple pieces of wire inserted into the correct pins.

PixeLINK Capture OEM Test Method 

To make the two cameras capture a frame, it is necessary to setup the camera parameters in the following manner, using PixeLINK Capture OEM to test the procedure.

1. Click Start | Run and type cmd

2. Click Ok, type "cd C:\Program Files (x86)\PixeLINK\Capture OEM", and press "Enter"

3. Type "PxLDevApp.exe /allowmultipleinstances" and press "Enter"

4. Repeat step 2 and 3, to open another instance of Capture OEM

For both cameras, define the Region of Interest (ROI), Decimation, Frame Rate, Data Format, and Shutter (integration)Time to suit your requirements.  Keep in mind, there are limitations on the bandwidth available when running two cameras on the same FireWire OHCI card.  It is also important to understand the frame rate and shutter time, and the time required to output a frame, so that the camera input triggers are coming at an appropriate interval.

Preview both cameras in Free Running mode, using the External Control tab, to frame and focus the camera.  If you're unable to preview both images, you'll need to adjust the shutter (exposure) time, ROI size, and frame rate on the Basic Controls tab until you're able to see both images without interruption.

Once the imaging characteristics are defined for both cameras, use the External Control tab to put one camera into Hardware Trigger mode, using Trigger Mode 0. The preview window for that camera will say “Input Unavailable”. 

Use the External Control tab to put the other camera into Software Trigger mode, with Trigger Mode 0. The preview window for that camera will say “Input Unavailable”. 

Next, select the camera that is the primary camera, using the dropdown menu in the External Control tab.  Chose GPO Number 1, and enable it.  Define the following settings for the primary camera:

Click on the button labelled “Update GPO”. 

To capture an image select the Image Capture tab and click "Capture".