The application uses Channel Access libraries, therefore it is already integrated with EPICS. 2).Ī motif based application is used to display captured images in live mode. It also shows both vertical and horizontal distributions of the images pixel intensity, and includes an image save option (Fig. improves signal-to-noise ratio), maximum pixelintensity calculation, standard deviation, and calibration.Īn medm GUI is used to control the camera and EPICS server parameters, such as start/stop image transmission, region of interest selection, frame rate, shutter gain and threshold control. Moreover, the server performs on-line centriod finding algorithm, background subtractions, averaging (i.e. Any Channel Access (EPICS) based application can retrieve an image from the waveform. First the single image is captured, processed and then placed in the waveform. An image acquisition process is repeated periodically. *video1394: Fast DMA frame transfer driver.Īt the user space level, Libraw1394 is a library that provides access to the raw1394 bus module and Libdc1394 is a high level API.įig1: System Schematic & System ComponentsĮPICS device support uses non-polling (blocking) DMA capture functions for image acquisition. *raw1394: Higher level driver module for bus access. Recent Linux kernels (> 2.4) are coming with built-in IEEE1394 modules: *ieee1394: Core of the IEEE1394 subsystem. The layered architecture of the EPICS server is presented in Fig. In the following, we explain software and hardware aspects, and typical applications of Firewire camera based systems at the SLS.ĮPICS based image acquisition server depends on several software components which can be dynamically loaded to the Linux kernel at run time. In addition, an X windows (motif) application was developed to provide a live feed from the camera by reading the image waveform. Linux offers open source libraries that support Firewire devices, thus it appeared to be well suited for the camera integration. We decided to benefit from interfacing a Firewire camera to an EPICS server running on a Linux PC. Recent development in EPICS (3.14.x) has allowed for an operating system independent implementation. In order to fulfill all requirements in the SLS, it was decided to integrate the Firewire cameras to the existing control system. These cameras are more preferment, offering more valuable features in comparison to traditional analogue cameras. Many new cameras are equipped with Firewire interface. The IEEE1394 bus supports both Plug-and-Play and hot plugging, and also provides power to peripheral devices. This makes it ideal for devices that need to transfer high priority data in real-time, such as video devices. In addition to its high speed, IEEE1394 also supports isochronous data - delivering data at a guaranteed rate. A single IEEE 1394 port can be used to connect up to 63 external devices. EPICS Video Server using Firewire Camera FIREWIRE CAMERASįirewire (IEEE1394) is a very fast external bus standard that supports data transfer rates of up to 400Mbps in IEEE 1394a, and up to 3.2 Gbps in IEEE1394b.
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