Real-Time Capability

In many typical surveillance situations, such as monitoring the activity on a banking floor, the user needs an automatically captured, continuous stream of images without the need to trigger a camera. If a camera is set for a frame rate of 30 frames (images) per second, it will internally generate the signals required to initiate an image capture every 1/30th of a second.

In some other situations, however, it would be desirable to be able to trigger an image capture at a specific point in time. For example, in a traffic control situation the user might want to trigger an image acquisition immediately after a car passes a sensor on a highway. In Basler IP cameras there is a real-time trigger feature that guarantees that an image capture will start exactly after a trigger signal is applied. For the typical frame rates for IP cameras, the required latency time is in the milliseconds range. The IP camera delivers compressed images (MJPEG/MPEG-4/H.264), which requires less bandwidth than images from an industrial camera.

For industrial cameras, real-time images are a prerequisite. For example, when inspecting components in a production process, the components are transported on the conveyor belts at high speed. For a precise inspection, the camera must acquire the images as quickly as the components are being transported. Timing this precisely requires low latency: a small time delay between receiving the trigger signal and acquiring the image. Further, the time delay must not vary; no jitter can affect the moments of image acquisition. For an application with high image rates (e.g. 300 images per second), the required latency times can be only microseconds.