Each sample chamber at CXI has two cameras – inline and off-axis – used for alignment, experiment viewing, and analysis. The image streams are served via an EPICS IOC viewable from the camViewer, and can be included in the CXI primary or secondary DAQ data streams via the IOC recorder.
(Picture of like an opal or something and maybe a screenshot)
Each camera has a host server that is running an EPICS IOC to handle low-level command, image acquisition, and to broadcast the data via channel access. Recorded cameras need to run on IOC hosts with hard disk drives, so the CXI sample chamber cameras run on ioc-cxi-rec03 (Rack 59 : Red Hat 5) and ioc-cxi-rec04 (Rack 52A : Red Hat 7). Access to the host and IOC process can be achieved using the IOC manager. The cameras are also synced to LCLS timing, and thus require a TTL trigger signal from their host's EVR hardware – typically a SLAC EVR PCI card in the server chassis. This is usually routed from the host to the camera via a user patch panel over coaxial cable.
Troubleshooting Tip:
If the trigger signal is disconnected from the camera, the IOC will continue to report that the camera is connected but will stop acquiring images! If a camera is not triggering properly, verify that there are no connection interruptions between the host and the camera and take a look at the camera's sync settings on its expert screen.
(Screenshot of expert screen)
The expert screens for each camera can be pulled up from the CXI Home Screen, on the left sidebar under the IOC Cameras dropdown menu.
(Screenshot of dropdown menu)
As a result of changing setups, hutch reconfiguration and different experiment requirements, the type of camera used at a sample chamber may change. Most often, GigE type cameras or "framegrabber" type cameras such as an Adimec Opal are used. GigE cameras are powered over ethernet so they need only be connected to a trigger signal and a network switch on the cds-cxi.pcdsn subnet with PoE capability to maintain function. Frame grabber cameras communicate over optical fiber, which is transceived on either side by EDT RCX camera links. RCX camera links require separate power (5V), and must be configured to the correct blink code in order to send and receive data between the camera and frame grabber PCI card. If a camera link fails then the IOC host will lose connection to the camera. Network and fiber connections to the sample chamber cameras are routed from the racks to the camera via a user patch panel.
SOME INFO ABOUT PREFERED SETTINGS FOR THE CAMERAS.
INFO ABOUT DIFFERENCES BETWEEN CAMERAS, MOTORIZED OPTICS, ETC.